Abstract
A rotor (2) for an electric machine (1) includes a rotor shaft (3) having at least one cooling duct (4), through which a coolant is flowable, and a laminated core (5) arranged on the rotor shaft (3). The laminated core (5) is arranged axially between a first end plate (6) and a second end plate (7) arranged on the rotor shaft (3). The laminated core (5) includes multiple axial ducts (8) for guiding the coolant through the rotor (2). The axial ducts (8) are fluidically connected to at least one distribution duct (9) in the particular end plate (6, 7) for the inflow of the coolant. The axial ducts (8) are fluidically connected to at least one return duct (16) in the particular other end plate (7, 6) for the outflow of the coolant. The at least one distribution duct (9) in the particular end plate (6, 7) is fluidically connected to the at least one cooling duct (4) at the rotor shaft (3).
Claims
1-15. (canceled)
16. A rotor (2) for an electric machine (1), comprising: a rotor shaft (3) including at least one cooling duct (4) formed within the rotor shaft (3) and through which a coolant if flowable; a first end plate (6) arranged on the rotor shaft (3); a second end plate (7) arranged on the rotor shaft (3); and a laminated core (5) arranged on the rotor shaft (3), the laminated core (5) arranged axially between the first end plate (6) and the second end plate (7), wherein the laminated core (5) includes a plurality of axial ducts (8) for guiding the coolant through the rotor (2), each of the plurality of axial ducts (8) is fluidically connected to at least one distribution duct (9) in a respective one of the first and second end plates (6, 7) configured for inflow of the coolant, each of the plurality of axial ducts (8) is fluidically connected to at least one return duct (16) in a respective one of the first and second end plates (7, 6) configured for outflow of the coolant, and the at least one distribution duct (9) in the respective one of the first and second end plates (6, 7) configured for inflow of the coolant is fluidically connected to the at least one cooling duct (4) at the rotor shaft (3).
17. The rotor (2) of claim 16, wherein an inflow (10) for the coolant is formed at an inner circumference of the respective one of the first and second end plates (6, 7) configured for inflow of the coolant, and the inflow (10) is fluidically connected to the at least one distribution duct (9).
18. The rotor (2) of claim 16, wherein an outflow (11) for the coolant is formed by at least one end-face opening (12) in the return duct (16) of the respective one of the first and second end plates (7, 6) configured for outflow of the coolant.
19. The rotor (2) of claim 18, wherein the at least one end-face opening (12) is configured for spraying coolant onto components of the electric machine (1).
20. The rotor (2) of claim 18, wherein the at least one opening (12) is configured for accommodating an orifice (20).
21. The rotor (2) of claim 16, wherein the at least one distribution duct (9) are each configured as an indentation in an end face of the respective one of the first and second end plates (6, 7) configured for inflow of the coolant facing the laminated core (3), and the at least one return duct (16) are each configured as an indentation in an end face of the respective one of the first and second end plates (7, 6) configured for outflow of the coolant facing the laminated core (3).
22. The rotor (2) of claim 16, wherein the plurality of axial ducts (8) are formed in the laminated core (5) such that the plurality of axial ducts (8) are continuously distributed over a circumference of the stator (2).
23. The rotor (2) of claim 16, wherein the plurality of axial ducts (8) are configured for being impinged upon by a flow of coolant from the first end plate (6) and the second end plate (7) in alternation.
24. The rotor (2) of claim 16, wherein cooling fins (13) for heat dissipation are formed in the plurality of axial ducts (8).
25. The rotor (2) of claim 24, wherein: each of the plurality of cooling fins (13) comprises a first web (14a), a second web (14b), and a third web (14c); and the first, second, and third webs (14a, 14b, 14c) divide each of the plurality of axial ducts (8) into three axial duct areas and extend at least partially in the axial direction of the respective axial duct of the plurality of axial ducts (8).
26. The rotor (2) of claim 16, wherein each of the plurality of axial ducts (8) comprises a fluid seal.
27. The rotor (2) of claim 16, wherein each of the plurality of axial ducts (8) comprises means for forming turbulence.
28. The rotor (2) of claim 16, wherein the plurality of axial ducts (8) are arranged at the rotor (2) proximate magnets (15).
29. The rotor (2) of claim 16, wherein the at least one distribution duct (9) and the at least one return duct (16) are each designed in an I-shape or a Y-shape in the respective one of the first and second end plates (6, 7).
30. An electric machine (1) for driving a motor vehicle, comprising the rotor (2) of claim 16.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] 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:
[0028] FIG. 1 shows a perspective schematic of an only partially represented electric machine according to example aspects of the invention;
[0029] FIG. 2 shows a diagrammatic longitudinal sectional representation of the example electric machine according to FIG. 1;
[0030] FIG. 3 shows a perspective schematic of two end plates and an only partially represented rotor of the example electric machine according to FIG. 1 and FIG. 2;
[0031] FIG. 4a shows a perspective schematic of one of the two identically designed end plates according a first exemplary embodiment;
[0032] FIG. 4b shows a perspective schematic of one of the two identically designed end plates according a second exemplary embodiment;
[0033] FIG. 5 shows a diagrammatic cross-sectional representation of the example electric machine according to FIG. 1 through FIG. 3; and
[0034] FIG. 6 shows a diagrammatic cross-sectional representation of a preferably designed axial duct in the laminated core of the rotor.
DETAILED DESCRIPTION
[0035] 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.
[0036] According to FIG. 1, an only partially represented electric machine 1 according to example aspects of the invention includes a housing-affixed stator 17 and a rotatable rotor 2, which is arranged within the stator 17 and, in the present case, is concealed by the stator 17, i.e., is not visible. In FIG. 1, all that is visible of the rotor 2 is a rotor shaft 3 having a cooling duct 4 formed therein.
[0037] According to FIG. 2, the electric machine 1 according to FIG. 1 is represented in a longitudinal section, wherein the rotor 2 is visible in a cutting plane in the present case. The rotor 2 includes the rotor shaft 3 and a laminated core 5 arranged on the rotor shaft 3. The rotor shaft 3 has a cooling duct 4, wherein coolant flows through the cooling duct 4 in order to cool the rotor shaft 3. Moreover, the laminated core 5 has multiple axial ducts 8, which are fluidically connected to the cooling duct 4 in the rotor shaft 3 in order to cool the rotor 2. For this purpose, a first end plate 6 and a second end plate 7 are arranged on the end faces of the laminated core 5 and coaxially to the rotor shaft 3.
[0038] Multiple distribution ducts 9, which are distributed over the circumference, are formed as an indentation in the end face of the particular end plate 6, 7 facing the laminated core 5. The distribution ducts 9 are utilized for introducing the coolant out of the cooling duct 4 into the axial ducts 8. Moreover, multiple return ducts 16, which are distributed over the circumference, are also formed as an indentation in the end face of the particular end plate 6, 7 facing the laminated core 5. The return ducts 16 are utilized for discharging the coolant out of the axial ducts 8.
[0039] According to FIG. 1 and FIG. 2, the stator 17 includes winding overhangs 18 toward both end faces, which protrude out of the end faces of the stator 17. These winding overhangs 18 are sprayed by three coolant jets 19 on both sides and are cooled as a result, wherein only two of the three coolant jets 19 are represented in the present case. The coolant flows via the cooling duct 4 in the rotor shaft 3 into the distribution ducts 9 at the first end plate 6 and the second end plate 7. The distribution ducts 9 introduce the coolant into the axial ducts 8 formed in the laminated core 5. Via the return ducts 16 in the particular end plate 6, 7, the coolant is discharged out of the axial ducts 8 via a particular outflow 11. The outflow 11 for the coolant is formed by an end-face opening 12 in the particular return duct 16 of the particular end plate 6, 7. This opening 12 is configured for spraying coolant, in a targeted and controlled manner, onto components of the electric machine 1, in the present case onto the winding overhangs 18 of the stator 17. For this purpose, a particular orifice 20 is arranged in the particular opening 12, which adjusts the coolant flow, in particular the through-flow and pressure, in the axial ducts 8.
[0040] In FIG. 3, the stator 17, the rotor shaft 3, and the laminated core 5 of the rotor 2 are not shown, wherein only the two end plates 6, 7, the axial ducts 8 formed in the laminated core 5, and the cooling duct 4 formed in the rotor shaft 3 are represented. The distribution ducts 9 and the return ducts 16 are distributed over the circumference of the particular end plate 6, 7 and arranged in alternation, wherein the three coolant jets 19 at the second end plate 7 spraying out of the openings 12 in the return ducts 16 are represented in the present case. Due to the perspective representation, only two of the three coolant jets 19 are visible at the return ducts 16 in the first end plate 6. Moreover, the distribution ducts 9 and the return ducts 16 in the second end plate 7 are also not visible in the present case due to the perspective representation.
[0041] FIG. 4a shows the first end plate 6 according to FIG. 3 in an enlarged perspective representation. The two end plates 6, 7 of the electric machine 1 are identically designed and, in the installed condition, are arranged on the end faces of the laminated core 5 turned by sixty degrees (60°) in the circumferential direction with respect to one another. The representation and explanation of the first end plate 6 also applies for the second end plate 7 due to the identical design. The distribution ducts 9 and the return ducts 16, which are distributed in an alternating and continuous manner in the circumferential direction, are designed as an indentation in the end face of the particular end plate 6, 7 facing the laminated core 5. Consequently, the axial ducts 8, which are fluidically connected thereto, are also formed in the laminated core 5 so as to be continuously distributed over the circumference of the rotor 2 (see FIG. 3). The axial ducts 8 are impinged upon by the flow of coolant from the first end plate 6 and the second end plate 5 in alternation in the circumferential direction in order to establish a homogeneous temperature distribution over the circumference of the rotor 2. The particular distribution duct 9 and the particular return duct 16 are designed essentially in a Y-shape, wherein the particular distribution duct 9 and the particular return duct 16 are simultaneously fluidically connected to multiple axial ducts 8. The inflow 10 for the coolant is designed as an end-face indentation at an inner circumference of the particular end plate 6, 7. The inflow 10 is designed in a ring shape and is fluidically connected to all three distribution ducts 9. By comparison, the outflow 11 for the coolant is formed by the particular end-face opening 12 in each of the three return ducts 16. Coolant is sprayed onto components of the electric machine 1 through the particular opening 12. The particular orifice 20 is accommodated in the particular opening 12 for adjusting a flow rate and a geometry of the coolant jet 19.
[0042] According to FIG. 4b, one further example embodiment for the end plates 6, 7 is represented. This example embodiment of the end plates 6, 7 has a simplified geometry for the distribution ducts 9 and the return ducts 16. In the installed condition at the electric machine 1, the identically designed end plates 6, 7 are arranged on the end faces of the laminated core 5 so as to be turned by sixty degrees (60°) in the circumferential direction with respect to one another. The distribution ducts 9 and the return ducts 16, which are distributed in an alternating and continuous manner in the circumferential direction, are designed as an indentation in the end face of the particular end plate 6, 7 facing the laminated core 5, and so the axial ducts 8 are impinged upon by the flow of coolant from the first end plate 6 and the second end plate 7 in alternation in the circumferential direction in order to establish a homogeneous temperature distribution over the circumference of the rotor 2. The particular distribution duct 9 and the particular return duct 16 are designed essentially in an I-shape, wherein the particular distribution duct 9 and the particular return duct 16 are simultaneously fluidically connected to multiple axial ducts 8. The inflow 10 for the coolant is designed as an end-face indentation at an inner circumference of the particular end plate 6, 7. The inflow 10 is designed in a ring shape and is fluidically connected to all three distribution ducts 9. By comparison, the outflow 11 for the coolant is formed by the particular end-face opening 12 in each of the three return ducts 16. Coolant is sprayed onto components of the electric machine 1 through the particular opening 12.
[0043] FIG. 5 shows a cross-section of the rotor 2 of the electric machine 1 according to FIG. 1 through FIG. 3. According to this preferred example embodiment, eighteen (18) magnets 15 are arranged in the laminated core 5 of the rotor 2. The pattern formed from the three magnets 15 labeled with reference characters repeats uniformly five times in the circumferential direction. Moreover, according to this preferred example embodiment, forty-two (42) axial ducts 8 are arranged in the laminated core 5 of the rotor 2, wherein the pattern formed from the seven axial ducts 8 labeled with reference characters repeats uniformly five times in the circumferential direction. In the present case, each of three magnets 15 of elongate design is arranged between two axial ducts 8. In each case, three magnets 15 of elongate design essentially form, together, a triangle, wherein an axial duct 8 having a round and larger cross-sectional area is arranged in the center of each particular triangle. The arrangement of the axial ducts 8 in the area of the magnets 15 enables an efficient cooling of the rotor 2. The coolant is introduced into the axial ducts 8 via the cooling duct 4 formed in the rotor shaft 3 and the distribution ducts 9 formed in the end plates 6, 7 and is sprayed onto the winding overhangs 18 of the stator 17 via the openings 12 in the return ducts 16 of the end plates 6, 7.
[0044] FIG. 6 shows one preferred example embodiment of an axial duct 8 in the laminated core 5 of the rotor 2. In the present case, a cooling fin 13 is formed in the axial duct 8 for improved heat dissipation. The cooling fin 13 has a first web 14a, a second web 14b, and a third web 14c, wherein the three webs 14a, 14b, 14c divide the axial duct 8 into three axial duct areas. The cooling fin 13 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 in the radial direction via the laminated core 5. Optionally, although not represented here, means for forming turbulence can be formed in the axial ducts 8, preferably at the cooling fins 13.
[0045] 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
[0046] 1 electric machine [0047] 2 rotor [0048] 3 rotor shaft [0049] 4 cooling duct [0050] 5 laminated core [0051] 6 first end plate [0052] 7 second end plate [0053] 8 axial duct [0054] 9 distribution duct [0055] 10 inflow [0056] 11 outflow [0057] 12 opening [0058] 13 cooling fin [0059] 14a first web [0060] 14b second web [0061] 14c third web [0062] 15 magnet [0063] 16 return duct [0064] 17 stator [0065] 18 winding overhang [0066] 19 coolant jet [0067] 20 orifice
