Abstract
A stator (2) for an electric machine (1) includes a laminated core (3) arranged axially between a first end plate (4) and a second end plate (5). A cooling line (6) for introducing a coolant into at least one distribution duct (7) at the particular end plate (4, 5) is arranged outside the end plates (4, 5) and the stator (2) and is fluidically connected to the at least one distribution duct (7) in the particular end plate (4, 5). The laminated core (3) includes multiple axial ducts (8) for guiding the coolant through the stator (2). The axial ducts (8) are fluidically connected to the at least one distribution duct (7) in the particular end plate (4, 5) for the inflow of the coolant. An outflow for the coolant is formed by at least one end-face opening (9) in the particular end plate (4, 5). The at least one opening (9) is configured for spraying the coolant out of the axial ducts (8) onto winding overhangs (10) of the stator (2).
Claims
1-15. (canceled)
16. A stator (2) for an electric machine (1), comprising: a laminated core (3) arranged axially between a first end plate (4) and a second end plate (5); a cooling line (6) configured for introducing a coolant into at least one distribution duct (7) at a particular one of the first and second end plates (4, 5), the cooling line (6) arranged outside the first and second end plates (4, 5) and the stator (2), the cooling line (6) fluidically connected to the at least one distribution duct (7) in the particular one of the first and second end plates (4, 5), wherein the laminated core (3) includes a plurality of axial ducts (8) configured for guiding the coolant through the stator (2), the axial ducts (8) fluidically connected to the at least one distribution duct (7) in the particular one of the first and second end plates (4, 5) as an inlet for the coolant, an outlet for the coolant formed by at least one end-face opening (9) in the particular one of the first and second end plates (4, 5), the at least one end-face opening (9) configured for spraying the coolant out of the axial ducts (8) onto winding overhangs (10) of the stator (2).
17. The stator (2) of claim 16, wherein: a plurality of deflection ducts (14) are arranged in the particular one of the first and second end plates (4, 5); and each deflection duct (14) is configured for deflecting the coolant out of a respective one of the axial ducts (8) into a circumferentially adjacent one of the axial ducts (8).
18. The stator (2) of claim 17, wherein one or both of the at least one distribution duct (7) and the plurality of deflection ducts (14) are formed as indentations in an end face of the particular one of the first and second end plates (4, 5) facing the laminated core (3).
19. The stator (2) of claim 16, wherein the at least one distribution duct (7) is formed as an indentation in an end face of the particular one of the first and second end plates (4, 5) facing the laminated core (3).
20. The stator (2) of claim 16, wherein an inflow (11) for the coolant is formed at an outer circumference of the particular one of the first and second end plates (4, 5), and the inflow (11) is fluidically connected to the at least one distribution duct (7).
21. The stator (2) of claim 16, wherein the at least one distribution duct (7) is formed at the particular one of the first and second end plates (4, 5) continuously, at least in sections, in the circumferential direction.
22. The stator (2) of claim 16, wherein the at least one distribution duct (7) includes multiple recesses (12) formed in the radial direction for introducing the coolant into the particular axial duct (8).
23. The stator (2) of claim 22, wherein: a plurality of deflection ducts (14) are arranged in the particular one of the first and second end plates (4, 5); and each deflection duct (14) is formed circumferentially between a respective recess (12) and a respective opening (9); each deflection duct (14) is configured for deflecting the coolant out of a respective one of the axial ducts (8) into a circumferentially adjacent one of the axial ducts (8).
24. The stator (2) of claim 16, wherein the at least one opening (9) is configured for accommodating an orifice (13).
25. The stator (2) of claim 16, wherein the axial ducts (8) are formed in the laminated core (3) such that the axial ducts (8) are distributed over a circumference of the stator (2).
26. The stator (2) of claim 16, wherein the axial ducts (8) are configured such that the flow of coolant from the first end plate (4) and the second end plate (5) alternatingly impinges upon the axial ducts (8) in order to establish a homogeneous temperature distribution over a circumference of the stator (2).
27. The stator (2) of claim 16, further comprising a plurality of cooling fins (15) formed in the axial ducts (8) and configured for heat dissipation.
28. The stator (2) of claim 27, wherein at least one of the cooling fins (15) comprises a first web (16a), a second web (16b), and a third web (16c), and the first, second, and third webs (16a, 16b, 16c) divide the axial duct (8) into three axial duct portions and extend at least partially in an axial direction of the axial duct (8).
29. The stator (2) of claim 16, wherein the axial ducts (8) comprise a fluid seal.
30. The stator (2) of claim 16, wherein the axial ducts (8) are arranged proximate stator teeth (22).
31. An electric machine (1) for driving a motor vehicle, comprising the stator (2) of claim 16.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] Preferred exemplary embodiments of the invention are explained in greater detail in the following with reference to the drawings, wherein identical elements are labeled with the same reference character, wherein
[0032] FIG. 1 shows a perspective schematic of an electric machine according to example aspects of the invention,
[0033] FIG. 2 shows a diagrammatic longitudinal sectional representation of the electric machine according to FIG. 1,
[0034] FIG. 3 shows a perspective schematic of two end plates and axial ducts arranged therebetween in a transparently represented stator of the electric machine according to FIG. 1 and FIG. 2,
[0035] FIG. 4 shows a perspective schematic of one of the two identically designed end plates according to FIG. 3,
[0036] FIG. 5 shows a diagrammatic detailed sectioning through multiple axial ducts of the stator,
[0037] FIG. 6 shows an enlarged detailed schematic of an axial duct according to FIG. 5, and
[0038] FIG. 7 shows an enlarged detailed schematic of an axial duct according to one further exemplary embodiment.
DETAILED DESCRIPTION
[0039] Reference will now be made to embodiments of the invention, one or more examples of which are shown in the drawings. Each embodiment is provided by way of explanation of the invention, and not as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be combined with another embodiment to yield still another embodiment. It is intended that the present invention include these and other modifications and variations to the embodiments described herein.
[0040] According to FIG. 1, an electric machine 1 according to example aspects of the invention includes a housing-affixed stator 2 and a rotatable rotor 17, which is arranged within the stator 2 and, in the present case, is partially concealed by the stator 2. The rotor 17 includes a rotor shaft 18 having a cooling duct 19 formed therein. A first end plate 4 and a second end plate 5 are arranged on the end faces of a laminated core 3 of the stator 2. Consequently, the laminated core 3 of the stator 2 is arranged axially between the two end plates 4, 5. Moreover, a cooling line 6 is arranged outside the end plates 4, 5 and the stator 2, which is configured for guiding and introducing a coolant into a particular distribution duct 7 at the particular end plate 4, 5 and, for this purpose, is fluidically connected to the particular distribution duct 7 in the particular end plate 4, 5. The distribution ducts 7 in the particular end plate 4, 5 are not shown in FIG. 1, for reasons related to perspective, although the distribution ducts 7 are represented in the following figures.
[0041] According to FIG. 2, the electric machine 1 according to FIG. 1 is represented in a longitudinal section. In FIG. 2, the cooling duct 19 in the rotor shaft 18 of the rotor 17 is clearly visible, wherein coolant flows through the cooling duct 19 in order to cool the rotor shaft 18. In the present case, the stator 2 is represented in a cutting plane and includes the laminated core 3 arranged axially between the two end plates 4, 5. The laminated core 3 includes multiple axial ducts 8 for guiding coolant through the stator 2. The axial ducts 8 are fluidically connected to the particular distribution duct 7 in the particular end plate 4, 5 for the inflow of the coolant. An outflow for the coolant takes place through multiple end-face openings 9 in the particular end plate 4, 5. The openings 9 are configured for spraying the coolant out of the axial ducts 8 onto winding overhangs 10 of the stator 2 in order, as a result, to also cool the winding overhangs 10 of the stator 2, which extend outwardly on the end faces. A particular orifice 13 is accommodated in the particular opening 9 for adjusting a flow rate and a geometry of a particular coolant jet 20. As a result, a larger wetting of the winding overhangs 10 with coolant is effectuated. The coolant jets 20 spraying out of the openings 9 are also shown in FIG. 1 and FIG. 3.
[0042] In FIG. 3, the rotor 17, the rotor shaft 18, and the laminated core 3 of the stator 2 are not shown, wherein only the two end plates 4, 5, the axial ducts 8 formed in the laminated core 3, and the cooling line 6 are represented. An inflow 11 for supplying coolant out of the cooling line 6 is formed at an outer circumference of each of the particular end plates 4, 5. The particular inflow 11 is fluidically connected to the particular distribution duct 7. Consequently, the coolant flows via the particular inflow 11 into the particular distribution duct 7 of the particular end plate 4, 5. The particular distribution duct 7 is formed continuously in the circumferential direction at the particular end plate 4, 5 and includes multiple recesses 12 formed in the radial direction for introducing the coolant into the particular axial duct 8. Moreover, multiple deflection ducts 14 are arranged in the particular end plate 4, 5. The particular deflection duct 14 is configured for deflecting the coolant out of one of the axial ducts 8 into an axial duct 8 adjacent thereto in the circumferential direction. The end-face openings 9 in the particular end plate 4, 5 act as an outflow for the coolant, wherein the coolant is sprayed out of the axial ducts 8 via the openings 9 onto the winding overhangs 10 of the stator 2. The coolant jets 20 represented in FIG. 1, FIG. 2, and FIG. 3 illustrate how the coolant is sprayed out of the openings 9. Due to the perspective representation, the distribution duct 7, the recesses 12, and the deflection ducts 14 in the second end plate 5 are not visible in the present case.
[0043] FIG. 4 shows one of the two end plates 4, 5 according to FIG. 1 through FIG. 3 in an enlarged perspective representation. The two end plates 4, 5 of the electric machine 1 are identically designed and, in the installed condition, are arranged on the end faces of the laminated core 3. The distribution duct 7 and the deflection ducts 14 are each designed as indentations in the end face of the particular end plate 4, 5 facing the laminated core 3. The inflow 11 for the coolant is also designed as an indentation at the outer circumference of the particular end plate 4, 5 and is fluidically connected to the distribution duct 7. The distribution duct 7 is formed continuously in the circumferential direction at the particular end plate 4, 5 and includes multiple recesses 12 formed in the radial direction for introducing the coolant into the particular axial duct 8. Each deflection duct 14 is formed between a recess 12 and an opening 9 in the circumferential direction. In the present case, the deflection duct 14 always follows the recess 12 in the clockwise direction, wherein the opening 9 follows the deflection duct 14 in each case. According to the present example embodiment, the particular end plate 4, 5 includes nine recesses 12, nine deflection ducts 14, and nine openings 9.
[0044] According to FIG. 3, the two end plates 4, 5, in the installed condition at the laminated core 3 of the stator 2, are turned with respect to each other in such a way that the particular recesses 12 at the first end plate 4 are always fluidically connected via a particular axial duct 8 to the particular deflection ducts 14 at the second end plate 5, wherein the particular deflection ducts 14 at the second end plate 5 are always fluidically connected, via one particular further axial duct 8, to the openings 9 at the first end plate 4. Consequently, the axial ducts 8 are configured for being impinged upon by the flow of coolant from the first end plate 4 and the second end plate 5 in alternation in order to establish a homogeneous temperature distribution over the circumference of the stator 2. The arrows in some of the axial ducts 8 and deflection ducts 14 visualize the flow direction of the coolant. According to the present example embodiment, a total of 36 axial ducts 8 are formed in a uniformly distributed manner in the laminated core 3 of the stator 2.
[0045] In FIG. 5, a detail of the stator 2 is represented, wherein five axial ducts 8 are shown in the laminated core 3 of the stator 2 in the present case. The axial ducts 8 are arranged in the area of stator teeth 22. In the present case, each of the axial ducts 8 is formed centrally between two stator grooves 21 in the circumferential direction and outside the stator teeth 22 in the radial direction. Cooling fins 15 are formed in the axial ducts 8 for improved heat dissipation, wherein the particular cooling fin 15 includes a first web 16a, a second web 16b, and a third web 16c. The three webs 16a, 16b, 16c divide the axial duct 8 into three axial duct areas and extend, at least partially, in the axial direction of the axial duct 8. As a result, an essentially heart-shaped cross-section of the particular axial duct area results.
[0046] FIG. 6 shows, in an enlarged view, one of the axial ducts 8 represented in FIG. 5. The axial duct 8 formed in the laminated core 3 of the stator 2 extends in a linear manner from a first end face of the stator 2 up to a second end face of the stator 2. The cooling fin 15 formed from the three webs 16a, 16b, 16c extends across the entire length of the axial duct and subdivides the axial duct into the three axial duct areas. The original cross-section of the axial duct 8 without the cooling fin 15 essentially corresponds to a triangle having inwardly rounded corners. This yields, in the present case, the three heart-shaped axial duct areas, which are partially turned and distorted.
[0047] FIG. 7 shows one further preferred example embodiment of an axial duct 8 in the laminated core 5 of the stator 2. In the present case, a cooling fin 15 is formed in the axial duct 8 for improved heat dissipation. The cooling fin 15 has a first web 16a, a second web 16b, and a third web 16c, wherein the three webs 16a, 16b, 16c divide the axial duct 8 into three axial duct areas. The cooling fin 15 extends in the axial direction of the axial duct 8 and includes a fluid seal, as is also the case for the wall of the axial duct 8 adjacent to the laminated core 5. Therefore, no coolant can leak out of the axial duct 8 into the stator 2 in the radial direction via the laminated core 3. The original cross-section of the axial duct 8 without the cooling fin 15 essentially corresponds to a triangle having outwardly rounded corners. This yields, in the present case, three elliptical arc-shaped axial duct areas, which are partially turned and distorted.
[0048] Modifications and variations can be made to the embodiments illustrated or described herein without departing from the scope and spirit of the invention as set forth in the appended claims. In the claims, reference characters corresponding to elements recited in the detailed description and the drawings may be recited. Such reference characters are enclosed within parentheses and are provided as an aid for reference to example embodiments described in the detailed description and the drawings. Such reference characters are provided for convenience only and have no effect on the scope of the claims. In particular, such reference characters are not intended to limit the claims to the particular example embodiments described in the detailed description and the drawings.
REFERENCE CHARACTERS
[0049] 1 electric machine
2 stator
3 laminated core
4 first end plate
5 second end plate
6 cooling line
7 distribution duct
8 axial duct
9 opening
10 winding overhang
11 inflow
12 recess
13 orifice
14 deflection duct
15 cooling fin
16a first web
16b second web
16c third web
17 rotor
18 rotor shaft
19 cooling duct
20 coolant jet
21 stator groove
22 stator tooth
