ELECTRIC MACHINE FOR A MOTOR VEHICLE, COIL CARRIER FOR AN ELECTRIC MACHINE, AND MOTOR VEHICLE

Abstract

An electric machine for a motor vehicle includes a rotor, and a stator interacting with the rotor. The stator includes a laminated core, a coil carrier configured for a flow of a cooling fluid there through, and a coil assembly having a plurality of stator coils and arranged in the coil carrier. The coil carrier has an enclosed configuration so as to form a fluid seal against the laminated core and the rotor.

Claims

1. An electric machine for a motor vehicle, comprising: a rotor; and a stator interacting with the rotor, said stator including a laminated core, a coil carrier configured for a flow of a cooling fluid there through, and a coil assembly having a plurality of stator coils and arranged in the coil carrier, said coil carrier having an enclosed configuration so as to form a fluid seal against the laminated core and the rotor.

2. The electric machine of claim 1, wherein the laminated core has several teeth, said coil carrier having through openings defined by walls and traversed by the teeth.

3. The electric machine of claim 2, wherein the walls of the coil carrier define flow passageways inside the coil carrier, with cooling fluid flowing through the flow passageways in an axial direction.

4. The electric machine of claim 3, further comprising a bulkhead extending in axial and radial directions and splitting at least one of the flow passageways.

5. The electric machine of claim 4, wherein the bulkhead is structured to generate turbulence in the cooling fluid flowing through the at least one of the flow passageways.

6. The electric machine of claim 2, wherein the teeth are configured for insertion into the laminated core and securement to the laminated core.

7. The electric machine of claim 1, wherein the coil carrier has an inlet line and an outlet line for circulation of the cooling fluid through the coil carrier.

8. The electric machine of claim 1, wherein the coil carrier has an opening which is sealed in a fluidtight manner, and an electrical connection received in the opening for connection to the coil assembly.

9. The electric machine of claim 1, wherein the coil carrier includes a plurality of ring-segment shaped coil carrier segments separated from one another in a fluidtight manner, and further comprising a plurality of said coil assembly, said coil assemblies received in the coil carrier segments in one-to-one correspondence.

10. The electric machine of claim 1, wherein the laminated core is made of a plurality of ring-segment shaped core segments.

11. The electric machine of claim 10, wherein the coil carrier includes a plurality of ring-segment shaped coil carrier segments separated from one another in a fluidtight manner and arranged on the stator in registry with the core segments.

12. The electric machine of claim 10, wherein the coil carrier includes a plurality of ring-segment shaped coil carrier segments separated from one another in a fluidtight manner and arranged on the stator in circumferential offset relationship to the core segments.

13. The electric machine of claim 1, wherein the coil carrier includes a plurality of ring-segment shaped coil carrier segments separated from one another in a fluidtight manner, each said coil carrier segment being made of multiple parts including an outer wall and a base body which is open towards the outer wall for receiving the outer wall to close the base body, said outer wall being fastened to the base body.

14. A coil carrier for an electric machine for a motor vehicle, said coil carrier comprising a hollow body configured for flow of a cooling fluid there through, said hollow body having a plurality of a coil receiving spaces for placement of stator coils of a coil assembly, respectively, said hollow body being configured so as to seal the coil assembly in a fluidtight manner against a laminated core and a rotor of the electric machine.

15. The coil carrier of claim 14, wherein the hollow body includes walls to define through openings for traversal of teeth of the electric machine.

16. The coil carrier of claim 15, wherein the walls define flow passageways in the hollow body for flow of cooling fluid there through in an axial direction.

17. The coil carrier of claim 16, further comprising a bulkhead extending in axial and radial directions and splitting at least one of the flow passageways.

18. The coil carrier of claim 17, wherein the bulkhead is structured to generate turbulence in the cooling fluid flowing through the at least one of the flow passageways.

19. The coil carrier of claim 14, wherein the coil carrier has an inlet line and an outlet line for circulation of the cooling fluid through the coil carrier and/or an opening which is sealed in a fluidtight manner, with an electrical connection received in the opening for connection to the coil assembly.

20. The coil carrier of claim 14, wherein the coil carrier is made of multiple parts including an outer wall and a base body which is open towards the outer wall for receiving the outer wall to close the base body, said outer wall being fastened to the base body.

21. A motor vehicle, comprising an electric machine, said electric machine comprising a rotor, and a stator interacting with the rotor, stator including a laminated core, a coil carrier configured for a flow of a cooling fluid there through, and a coil assembly having a plurality of stator coils and arranged in the coil carrier, said coil carrier having an enclosed configuration so as to form a fluid seal against the laminated core and the rotor.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0027] Other features and advantages of the present invention will be more readily apparent upon reading the following description of currently preferred exemplified embodiments of the invention with reference to the accompanying drawing, in which:

[0028] FIG. 1 is a basic cross sectional illustration of an electric machine according to the present invention;

[0029] FIG. 2 is a perspective view of a stator of the electric machine of FIG. 1;

[0030] FIG. 3 is a perspective view of a coil carrier segment of the electric machine of FIG. 1;

[0031] FIG. 4 is a perspective view of a base body of the coil carrier segment of FIG. 3;

[0032] FIG. 5 is a perspective detailed view of a modified bulkhead for placement in the coil carrier segment of FIG. 3; and

[0033] FIG. 6 is a schematic basic representation of a motor vehicle according to the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0034] Throughout all the figures, same or corresponding elements may generally be indicated by same reference numerals. These depicted embodiments are to be understood as illustrative of the invention and not as limiting in any way. It should also be understood that the figures are not necessarily to scale and that the embodiments may be illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted.

[0035] Turning now to the drawing, and in particular to FIG. 1, there is shown a basic cross sectional illustration of an electric machine according to the present invention, generally designated by reference numeral 1. The electric machine 1 includes a stator 2 and a rotor 3 which is coupled to a shaft 5 rotating about a rotation axis 4.

[0036] The electric machine 1 includes a coil carrier 6 which is inserted into slots 7 of a laminated core 8 of the stator 2 and is configured in the form of a hollow body flowed through by a cooling fluid in a direction of arrow 9. The slots 7 are respectively formed between two adjacent teeth 10 of the laminated core 8, with the teeth 10 extending through through openings 12 of the coil carrier 6, with the through openings 12 being bounded by walls 11. Arranged in each of plural coil receiving spaces 13 is a stator coil 14 of several coil assemblies 15. A bulkhead 16 of the coil carrier 6 is arranged between each two through openings 12 or stator coils 14, with cooling fluid flowing along the bulkhead 16 through the coil carrier 6. Cooling fluid enters through inlet lines 17 on one end face of the coil carrier 6 and exits through outlet lines 18 on an opposite end face of the coil carrier 6. The coil carrier 6 further includes openings 19 at an end face for electric feeds for the coil assemblies 15. The coil carrier 6 thus has an enclosed configuration so as to form a fluid seal against the laminated core 8 and the rotor 3.

[0037] FIG. 2 shows a perspective view of the stator 2 of the electric machine 1 with the coil carrier 6. As is readily apparent from FIG. 2, the coil carrier 6 is comprised of four ring-segment shaped coil carrier segments 20 which are arranged in a fluidtight manner relative to one another. Each coil carrier segment 20 receives a coil assembly 15 and includes a corresponding one of the inlet lines 17, a corresponding one of the outlet lines 18, and the openings 19 for a corresponding electric feed.

[0038] FIG. 2 further shows the teeth 10 of the laminated core 8 to respectively extend through the through openings 12 of the coil carrier 6 so that each of the stator coils 14 is arranged about a corresponding one of the teeth 10 for a magnetic flux, generated by the stator coils 14, to be conducted in the direction of the rotor 3. By dividing the coil carrier 6 into the coil carrier segments 20, it becomes possible to place the coil carrier segments 20 upon the teeth 10, when assembling the electric machine 1, with clearances being provided depending on the circumference of the stator 2 and with the slots 7 being formed with parallel flanks. Although not shown in greater detail, the teeth 10 may also be configured for insertion into the laminated core 8 and for securement thereto. In this way, tooth geometries can be realized that do not allow per se a placement of the coil carrier segments 20, like teeth with parallel flanks or special tooth heads.

[0039] As is further readily apparent from FIG. 2, the laminated core 8 is comprised of four core segments 21 which are arranged in a congruent manner with the coil carrier segments 20. When assembling the electric machine 1, the coil carrier segments 20 may initially be inserted onto the corresponding ones of the core segments 21, and the core segments 21 are then joined together to form the laminated core 8 through securement in a detachable or permanent manner. In this way, the afore-described clearance between the coil carrier segments 20 may be omitted. Although not shown in detail, the coil carrier segments 20 and the core segments 21 may also be arranged in circumferential offset relationship so as to establish an overlap. It is also conceivable to use a single-piece coil carrier 6 onto which the core segments 21 can be placed from outside, when assembling the electric machine 1.

[0040] FIG. 3 is a perspective view of one of the coil carrier segments 20 of the electric machine 1. Readily apparent from FIG. 3 are the individual through openings 12 which are bounded on four sides by the walls 11 to thereby establish a ribbed structure for engagement of the teeth 10 of the laminated core 8.

[0041] The coil carrier segment 20 includes a base body 22 (shown in greater detail in FIG. 4) and a separate outer wall 23 which extends in axial and circumferential directions. This split configuration enables a simple arrangement of the stator coils 14 by placing them into the trough-shaped base body 22. The outer wall 23 is then attached to the base body 22 by a joining process to close the base body 22. The base body 22 and the outer wall 23 are made of electrically insulating and thermally and mechanically resistant material, such as, e.g., polyetheretherketone (PEEK). Manufacture of the coil carrier segment 20 involves, e.g., a stereolithography process or a selective laser sintering process. In this way, slight material thicknesses of the walls 11, base body 22, and outer wall 23, can be realized.

[0042] While FIG. 3 shows the outer wall 23 in single-piece configuration with an end wall 24, it is, of course, also conceivable to use a separate end wall 24 instead of the outer wall 23. Although this would somewhat complicate the arrangement of the stator coils 14 in the respective base body. However, the coil carrier segment 20 requires only a single continuous joining seam about the end wall 24 in order to close the base body 22 coil carrier segment 20.

[0043] FIG. 4 is a perspective view of the base body 22 of the coil carrier segment 20 shown in FIG. 3. The base body 22 of the coil carrier segment 20 has the coil receiving spaces 13, respectively defined about the walls 11 of each through opening 12. A flow passageway 25 is further formed between the walls 11 of adjacent through openings 12, with a bulkhead 16 extending axially along the flow passageway 25 so as to divide the flow passageway 25 into two flow sub-passages. As a result, the flow cross section for the cooling fluid is reduced to thereby enhance heat dissipation. Cooling fluid flowing in the direction of arrow 9 through the flow sub-passages settles down thermally and hydrodynamically much later so as to achieve an improved Nusselt number of the flow process.

[0044] FIG. 5 is a perspective detailed view of a modified bulkhead 16 for placement in the coil carrier segment 20. In this variation, the bulkhead 16 is configured in axial direction with several notch-like structures 26 by which a turbulence is generated in the cooling fluid as it flows through the flow passageways 25. The turbulence of the cooling fluid causes targeted swirling to thereby further enhance heat dissipation of the stator coils 14 onto the cooling fluid. Configurations other than the notch-like structure 26 are, of course, also conceivable, such as, e.g. undulated structure, indented structure, or zigzag structure to generate the turbulence.

[0045] As described above, it is within the scope of the present invention, to provide a single-piece coil carrier 6 having a single hollow space which is closed in circumferential direction, Although FIG. 1 shows the rotor 3 of the electric machine as internal rotor, it is, of course, also conceivable to configure the rotor 3 as external rotor.

[0046] Referring now to FIG. 6, there is shown a schematic basic representation of a motor vehicle according to the present invention, generally designated by reference numeral 27. The motor vehicle 27 includes several wheels 29 which can be propelled by a drive train 28, and an electric machine 1 which is configured to at least temporarily and to at least assist a propulsion of the wheels 29 via the drive train 28.

[0047] While the invention has been illustrated and described in connection with currently preferred embodiments shown and described in detail, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit and scope of the present invention. The embodiments were chosen and described in order to explain the principles of the invention and practical application to thereby enable a person skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.

[0048] What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims and includes equivalents of the elements recited therein: