Electrical machine stator

Abstract

A stator for an electric machine (23) comprising a stator shaft (2) and a laminated core (3) with stator teeth (4) and stator slots (5) located between the stator teeth (4) and including a plurality of laminations (6), the stator teeth (4) being connected to one another via an annular stator yoke (7), a conductor bundle (10) including a single conductor (9) or a plurality of conductors (9), in particular a laminate of rectangular conductors, is provided in each of the stator slots (5) to form an electric stator winding (8), the stator slots (5) each having a slot base (5.1) facing the stator yoke (7) and a slot slot (5.2) facing in the opposite direction to the slot base (5.1), the stator shaft (2) being provided with a stator core (3) including a plurality of laminations (6) and ... a plurality of support points (11) spaced apart from one another in the axial direction are formed in each of the stator grooves (5) for supporting the conductors (9) or the conductor bundles (10) located in the respective stator grooves (5); at least one groove gap is formed between a wall (5.1, 4.2) of each of the stator grooves (5) and the conductors (9) or the conductor bundles (10) arranged in the stator grooves (5), the groove gap forming a groove gap flow passage (14) extending in the axial direction, in which a cooling medium, in particular oil, can flow along a cooling path (15), the respective groove gap flow passage (14) being at least narrowed at the support points (11); - the groove slot (5.2) of each stator groove (5) is closed by a groove closure (16); - a bypass (18) is provided in each of the stator grooves (5) at the support points (11) for transporting cooling medium past the narrowed support points (11) in the groove gap flow passages (14); - a stator, characterized in that the bypasses (18) at the different support points (11) of the same stator groove (5) are arranged at different radial positions so that a serpentine cooling path (15) is formed in the stator groove (5).

Description

Technical Field

[0001] The present invention is based on a stator of an electrical machine described in the generic concept of the independent claims.

Background Art

[0002] From German Patent Application Publication No. 102019113785, a stator shaft, stator teeth, and stator grooves located between the stator teeth are configured, and a laminated iron core including a plurality of thin plate pieces is provided. The stator teeth are interconnected via an annular stator yoke. A conductor bundle including a plurality of conductors is respectively provided in the stator grooves to form an electrical stator winding. The stator grooves respectively have a groove base facing the stator yoke and a groove slot facing the opposite direction of the groove base. A plurality of support points spaced apart from each other in the axial direction with respect to the stator shaft are respectively formed in the stator grooves to support the conductors or conductor bundles located in the respective stator grooves. At least one groove gap is formed between the wall portion of each stator groove and the conductor bundle arranged in the stator groove to form a groove gap flow path extending in the axial direction. A cooling medium, particularly oil, can flow through this groove gap flow path along the cooling path. Each groove gap flow path is at least narrowed at the support points. The stator of the electrical machine is known. Uniform cooling along the cooling path of each conductor bundle in the groove gap flow path is not guaranteed because, for example, a non-uniform flow distribution can occur across the flow cross-section of the groove gap flow path.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Means for Solving the Problems

[0004] On the one hand, the stator of the electric machine according to the invention having the inherent features of the independent claim has the advantage that each conductor bundle in the groove gap flow path along the cooling path is cooled more uniformly.

[0005] According to the invention, this is achieved in that the groove slots of each stator groove are closed by groove closures, and bypasses for transferring the cooling medium beyond the narrowed support points in the groove gap flow path are respectively provided in each stator groove at the support points, and the bypasses at different support points of the same stator groove are arranged at different radial positions so that a meandering cooling path is formed in the stator groove.

[0006] By means of the means recited in the dependent claims, advantageous improvements and modifications of the stator of the electric machine described in the independent claim are possible. It is particularly advantageous if the bypasses at different support points of the same stator groove are respectively configured in the groove base, in particular in or on the tooth surface of the groove base, or in the groove closure, so that a meandering cooling path having a radially wide meander is achieved, and thus very uniform cooling in the stator groove is achieved.

[0007] According to an advantageous embodiment, the bypasses at different support points of the same stator groove are alternately configured in the groove base or in the groove closure in order to form a meandering cooling path from one support point to the next. Alternatively, the meander may be configured to be long when viewed axially.

[0008] It is very advantageous if the bypass is formed, for example, by a groove-shaped bypass flow path. In this way, the bypass can be manufactured very easily in each stator groove of the laminated iron core of the stator. If the bypass flow path has a flow path width smaller than the conductor width of the conductor or conductor bundle, it is advantageously ensured that the conductor or conductor bundle cannot close or block the bypass flow path, for example by slipping into the bypass flow path.

[0009] It is also advantageous if the laminated core has a plurality of identical thin plate pieces, each of the identical thin plate pieces has a plurality of groove recesses forming stator grooves, and bypass recesses forming bypass channels are provided at the groove bases of specific groove recesses determined according to a pattern and distributed over the entire circumference with respect to each of the thin plate pieces. No bypass recesses are provided in the remaining groove recesses of the thin plate pieces. In this way, using the same thin plate pieces, bypasses can be formed at the groove bases of the respective stator grooves at predetermined axial positions of each stator groove of the laminated core. That is, even though an additional bypass according to the present invention is provided, the manufacturing cost of the laminated core does not increase or does not increase significantly.

[0010] This can be advantageously achieved by twisting a plurality of the same thin plate pieces in the laminated core about the stator axis such that the bypasses are formed in the individual stator grooves over a specific length at specific axial positions.

[0011] According to an advantageous embodiment, the groove closures of the stator grooves may each be formed by individual groove closure members or may be constituted by one or more in a separating tube. It is also advantageous if the support points are formed by twisting at least two thin plate pieces of the laminated core about the stator axis by a predetermined twist angle. In this way, the conductor bundles of the respective stator grooves are clamped between the two tooth surfaces at the respective support points. In order to reliably protect the electrical insulation of the conductor or conductor bundle, a protective member may be provided around the conductor bundle in the region of the support point as an alternative to the normally provided groove insulating paper. Thereby, it becomes possible to at least partially omit the use of the impregnating resin as an insulator in the groove gap between the laminated core and the conductor bundle.

[0012] Also, by twisting the thin plate pieces of the laminated core to form respective support points, support portions of the thin plate pieces protruding into the stator grooves from the opposing surfaces of the respective stator grooves are formed. As a result, on the holding surface of the conductor or conductor bundle, the conductor or conductor bundle is held, particularly clamped, between the support portions. In this way, it becomes possible to support the conductor or conductor bundle at the center or the center of each stator groove in the circumferential direction with respect to the stator axis.

[0013] The present invention further relates to an electric machine provided with a housing in which the stator according to the present invention is arranged. The stator winding forms winding heads on each end face of the stator, and in the housing on each end face of the stator, winding head cooling chambers for accommodating the respective winding heads are provided to cool the respective winding heads. The stator grooves starting from one of the two winding head cooling chambers can flow through the cooling path of the stator grooves to the other winding head cooling chamber. In this way, particularly good cooling of the stator can be achieved.

Brief Description of the Drawings

[0014] Embodiments of the invention are schematically shown in the drawings and will be described in detail in the following description.

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0015] FIG. 1 is a partial view of a stator of an electric machine according to the present invention. The stator 1 of the electric machine has a stator shaft 2, and stator teeth 4 and stator grooves 5 located between the stator teeth 4 are formed, and includes a laminated iron core 3 formed by a laminate of thin plate pieces 6.

[0016] The stator teeth 4 are connected to each other via an annular stator yoke 7 of the laminated iron core 3 and may have tooth heads 4.1. Either a single conductor 9 or a conductor bundle 10 including a plurality of conductors 9 forming an electrical stator winding 8 may be respectively provided in the stator groove 5. For the purpose of explaining the present invention, in FIG. 1, only one of the stator grooves 5 shows the conductor bundle 10.

[0017] The conductors 9 of the stator 1 can each be configured as flat conductors having a square, particularly rectangular, conductor cross-section. Further, the conductors 9 of the stator 1 can each be configured as hairpin conductor members or I-pin conductor members. The conductors 9 are coated, for example, with an insulating varnish by a known method.

[0018] FIG. 2 is a cross-sectional view of the stator described in FIG. 1, provided with a conductor bundle supported in one of the stator grooves at a plurality of support points according to the present invention. As shown in FIG. 2, in the stator groove 5, a plurality of, for example, three support points 11 that are axially spaced from each other with respect to the stator shaft 2 are respectively formed in the stator groove 5 for clamping, tightening, or supporting the conductor 9 or the conductor bundle 10 located in each stator groove 5.

[0019] The support points 11 can be formed, for example, by twisting at least two thin plate pieces 6 of the laminated core 3 by a predetermined twist angle φ with respect to the stator axis 2. By twisting the thin plate pieces 6 to form each support point 11, a support portion 6.1 of the thin plate piece 6 is formed, and this support portion 6.1 projects into each stator groove 5 from the opposing surface of the stator groove 5 in order to hold, for example, clamp the conductor bundle 10 between the support portions 6.1 of the holding surface 13 of the conductor bundle 10. The twisted thin plate pieces 6 are fixed to the laminated core 3 so as to prevent further twisting, particularly by material-bonded joining, so that stable and sustainable support points 11 are formed on the laminated core 3.

[0020] Between the support points 11 according to the invention, the conductor bundles 10 of the respective stator grooves 5 are, for example, freely floating, i.e., supported in a non-contact manner with respect to the laminated core 3. That is, the conductor bundles 10 of the respective stator grooves 5 are in contact with the laminated core 6 only, for example, at the support points 11.

[0021] A protective layer (not shown), particularly configured in a sleeve shape, cap shape, tubular shape, clamp shape, U-shape, strip shape or flat strip shape, may be provided between the conductor bundle 10 of each stator groove 5 and each support point 11.

[0022] FIG. 3 is a longitudinal cross-sectional partial view of an electric machine provided with the stator according to the invention shown in FIGS. 1 and 2. The stator groove 5 has a groove base 5.1 facing the stator yoke 7 and a groove slot 5.2 facing in the opposite direction to the groove base 5.1, particularly formed between two tooth heads 4.1 of each stator tooth 4.

[0023] At least one groove gap is formed between the wall portion of each stator groove 5 and the conductor 9 or conductor bundle 10 arranged in the stator groove 5, and this groove gap forms an axially extending groove gap flow path 14 through which a cooling medium, particularly oil, can flow along the cooling path 15.

[0024] Each groove gap flow path 14 of the stator groove is narrowed at least at the support point 11. According to the present invention, each groove slot 5.2 of each stator groove 5 is closed by a groove closing portion 16 toward a so-called gap when viewed in the radial direction, and bypasses 18 are respectively provided in each stator groove 5 at the support point 11 in order to transfer the cooling medium across the narrowed support point 11 in the groove gap flow path 14. Furthermore, according to the present invention, it is contemplated that the bypasses 18 are arranged at different radial positions with respect to the stator axis 2 at different support points 11 of the same stator groove 5 such that a meandering cooling path 15 is formed in the stator groove 5. The groove closing portion 16 seals or at least substantially seals the groove gap flow path 14 in the radial direction with respect to the gap.

[0025] The meandering cooling path 15 has at least one meander extending from the groove base 5.1 to the groove slot 5.2 and then to the groove base 5.1, or from the groove slot 5.2 to the groove base 5.1 and then to the groove slot 5.2 along the longitudinal direction of the stator groove 5 when viewed in the flow direction.

[0026] The bypasses 18 at different support points 11 of the same stator groove 5 are respectively arranged, for example, in the groove base 5.1, particularly in the groove base 5.1, or on the tooth surface 4.2 of the groove base 5.1, or in the groove closing portion 16 such that a meandering cooling path 15 is formed in the stator groove 5.

[0027] According to the embodiment of FIG. 3, the bypasses 18 at different support points 11 of the same stator groove 5 are alternately configured in the groove base 5.1 or the groove closing portion 16 from one support point 11 to the next support point 11 when viewed in the axial direction, thereby forming a meandering cooling path 15.

[0028] The electric machine 23 has a housing 24 in which the stator 1 according to the present invention is arranged. The stator winding 8 forms winding heads 8.1 on each end face of the stator 1. In the housing 24, winding head cooling chambers 25 for accommodating the respective winding heads 8.1 are provided on each end face of the stator 1 in order to cool the respective winding heads 8.1. Here, the stator grooves 5 of the stator 1 can flow from one of the two winding head cooling chambers 25 through the cooling path 15 of the stator grooves 5 to the other winding head cooling chamber 25, for example, by parallel connection, series connection, or a combination of parallel connection and series connection. Each winding head cooling chamber 25 is surrounded by an annular wall 26, for example, a seal sleeve, on the radially inner side with respect to the stator axis 2. The seal sleeve 26 may reach, for example, into the gap formed between the stator 1 and the rotor 27 of the electric machine 23 and penetrate this axially with respect to the stator axis 2.

[0029] The groove closing portion 16 of the stator groove 5 can be formed respectively by individual groove closing members arranged and attached in the respective stator grooves 5. Alternatively, the groove closing portion 16 of the stator groove 5 may be arranged in the gap between the stator 1 and the rotor 27 of the electric machine 23 and may be constituted by one or a plurality of so-called separation tubes made of, for example, fiber-reinforced plastic (CFRP, GFRP).

[0030] FIG. 4 shows one of the thin plate pieces of the stator according to the present invention described in FIGS. 1 to 3. The bypass 18 is formed respectively by a bypass flow path in the groove base 5.1, particularly in the groove base 5.1, or on or in the vicinity of the tooth surface 4.2 (shown by a broken line in FIG. 4) of the groove base 5.1, or in the groove closing portion 16 of each stator groove 5. The bypass flow path 18 is, for example, groove-shaped and / or has a flow path width b smaller than the conductor width B of the conductor bundle 10.

[0031] The bypass 18 of the groove base 5.1 is constituted respectively in the corresponding thin plate piece 6 of the laminated iron core 3 of the stator 1. The laminated core 3 has, for example, a plurality of identical thin plate pieces 6, and each of the identical thin plate pieces 6 has a plurality of groove recesses 20 that form the stator grooves 5. For each of the thin plate pieces 6, bypass recesses 19 that form bypass channels 18 are provided, for example, on the groove bases 5.1 of specific groove recesses 20 that are determined according to a pattern and are distributed over the entire circumference of the thin plate piece 6, and no bypass recesses 19 are provided in the remaining groove recesses 20 of the thin plate piece 6. That is, according to the pattern, bypass recesses 19 are formed in some of the groove recesses 20 of the thin plate piece 6, and bypass recesses 19 are not formed in the remaining portions of the groove recesses 20.

[0032] By twisting some of the identical thin plate pieces 6 of the laminated core 3 about the stator axis 2, it is possible to achieve the formation of bypasses 18 at desired axial positions and over a desired length in the individual stator grooves 5.

Claims

1. A stator of an electrical machine (23), comprising a stator shaft (2), a laminated core (3) including a plurality of thin plate pieces (6), and stator teeth (4) and stator grooves (5) located between the stator teeth (4), wherein the stator teeth (4) are interconnected via an annular stator yoke (7), and a conductor bundle (10) including a single conductor (9) or a plurality of conductors (9) is respectively provided in the stator grooves (5) to form an electrical stator winding (8); the stator grooves (5) respectively have a groove base (5.1) facing the stator yoke (7) and a groove slot (5.2) facing in a direction opposite to the groove base (5.1); a plurality of support points (11) spaced apart from each other in the axial direction with respect to the stator shaft (2) are respectively formed in the stator grooves (5) to support the conductor (9) or the conductor bundle (10) located in the stator grooves (5); at least one groove gap is formed between the wall portions (5.1, 4.2) of the respective stator grooves (5) and the conductor (9) or the conductor bundle (10) disposed in the stator grooves (5) to form an axially extending groove gap flow path (14), and a cooling medium can flow through the groove gap flow path (14) along a cooling path (15); in cases where the respective groove gap flow paths (14) are at least narrowed at the support points (11), - the groove slots (5.2) of the respective stator grooves (5) are closed by groove closing portions (16), - bypasses (18) for transferring the cooling medium beyond the narrowed support points (11) in the groove gap flow paths (14) are respectively provided in the respective stator grooves (5) at the support points (11), - the bypasses (18) at different support points (11) of the same stator groove (5) are arranged at different radial positions such that the cooling path (15) is formed in a meandering shape in the stator groove (5), characterized in that the bypasses (18) at different support points (11) of the same stator groove (5) are respectively configured on the groove base (5.1) such that the cooling path (15) is formed in a meandering shape in the stator groove (5). Stator, characterized by the above.

2. The stator according to claim 1, characterized in that the conductor bundle (10) is a laminate of flat conductors.

3. The stator according to claim 1, characterized in that the cooling medium is oil.

4. The stator according to claim 1, characterized in that the bypass (18) is respectively configured in the groove base (5.1), or on the tooth surface (4.2) of the groove base (5.1), or in the groove closing portion (16).

5.

5. The stator according to claim 1, characterized in that the bypasses (18) at the different support points (11) of the same stator groove (5) are alternately configured in the groove base (5.1) to form the cooling path (15) from one support point (11) to the next support point (11).

6. The stator according to claim 5, characterized in that the bypasses (18) are alternately configured in the groove base (5.1), or on the tooth surface (4.2) of the groove base (5.1), or in the groove closing portion (16).

7.

7. The stator according to claim 1, characterized in that the bypasses (18) are each formed by a bypass flow path, and the bypass flow path has a flow path width (b) smaller than the conductor width (B) of the conductor (9) or the conductor bundle (10).

8.

8. The laminated core (3) has a plurality of identical thin plate pieces (6), each of the identical thin plate pieces (6) has a plurality of groove recesses (20) forming the stator groove (5), and bypass recesses (19) forming the bypass flow path are provided in the groove base (5.1) of specific groove recesses (20) determined according to a pattern and distributed over the entire circumference for each of the thin plate pieces (6). The stator according to claim 7, characterized in that it is provided.

9.

9. In the laminated core (3), a plurality of the same thin plate pieces (6) are twisted around the stator axis (2) such that the bypass (18) is formed in the individual stator grooves (5) over a specific length at a specific axial position. The stator according to claim 8, characterized in that it is.

10.

10. The stator according to claim 1, characterized in that the groove closing portions (16) of the stator grooves (5) are each formed by individual groove closing members or are composed of one or more in a separation tube.

11. The stator according to claim 1, characterized in that the support points (11) are formed by twisting at least two thin plate pieces (6) of the laminated core (3) by a predetermined twist angle (φ) with respect to the stator axis (2).

12. By twisting the thin plate pieces (6) of the laminated core (3) to form the respective support points (11), a support portion (6.1) of the thin plate piece (6) protruding into the stator groove (5) from the opposing surface of the respective stator groove (5) is formed, whereby the conductor (9) or the conductor bundle (10) is held between the support portions (6.1) on the holding surface (13) of the conductor (9) or the conductor bundle (10). The stator according to claim 1, characterized in that

13. The stator according to claim 12, characterized in that the conductor (9) or the conductor bundle (10) between the support portions (6.1) is clamped.

14. An electromechanical machine comprising a housing (24) in which the stator (1) according to claim 1 is arranged, wherein the stator winding (8) forms a winding head (8.1) at each end face of the stator (1), and in the housing (24) at each end face of the stator (1), a winding head cooling chamber (25) for accommodating the respective winding head (8.1) is provided to cool the respective winding head (8.1), and the stator groove (5) starting from one of the two winding head cooling chambers (25) can flow through the cooling path (15) of the stator groove (5) to the other winding head cooling chamber (25). An electromechanical machine, characterized in that

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