Axial-flux electric machine and cooling plate of an axial-flux electric machine

Abstract

The present invention relates to an axial-flux electric machine (1), comprising a casing (2) and an active core, comprising at least one stator (7) and at least one rotor (8), the machine further comprising at least one cooling plate (9) with at least one internal cooling channel (10), the at least one cooling plate (9) being adjacent to the at least one stator (7).

Description

“AXIAL FLUX ELECTRIC MACHINE AND COOLING PLATE OF AN AXIAL FLUX ELECTRIC MACHINE” FIELD OF INVENTION

[0001] The present invention relates to an axial flux electrical machine and, more specifically, to an axial flux motor or generator. BACKGROUND OF THE INVENTION

[0002] Axial electromagnetic flux electric machines are widely known in the art and essentially comprise at least one stator and at least one disc-shaped rotor, in which the electromagnetic flux travels in the axial direction of the machine's rotating shaft. They can include both electric motors and electric generators.

[0003] In one of the known solutions for cooling axial flux motors, an external pump pumps cooling fluid into the motor (preferably inside the casing and / or stator) so that the fluid can extract heat from the motor.

[0004] Thus, it is known from the prior art to form cooling channels for the passage of cooling fluid through the internal components of the engine.

[0005] Document EP2606561, for example, shows an electrical machine with an annular chamber through which a cooling medium can circulate around the stator coils.

[0006] Document KR101999860, in turn, discloses an electric motor with a cooling solution comprising a cooling fluid distribution chamber that includes a portion of the introduced cooling fluid and a second cooling fluid distribution path for guiding another portion of the cooling fluid to the side of the rear cover.

[0007] Document WO2019 / 171318 discloses a cooling component for an electric motor comprising a channel defined by an outer ring, an inner ring concentric to the outer ring and linear segments extending radially from the inner ring towards the outer ring. OJECTIVES OF THE INVENTION

[0008] It is an object of the present invention to provide an axial flux electric machine with a cooling plate that enables greater heat extraction capacity.

[0009] It is another objective of the present invention to provide an axial flux electric machine with a cooling plate that allows a cooling channel whose heat exchange area presents greater efficiency in relation to the machine's stator.

[0010] It is another object of the present invention to provide an axial flux electric machine with a cooling plate that is part of the structural assembly of the machine.

[0011] It is yet another object of the present invention to provide an axial flux electric machine with a cooling plate that is capable of making the connection between two stators. Summary of the Invention

[0012] The present invention relates to a cooling plate for an axial flux electrical machine and to an axial flux electrical machine comprising at least one cooling plate.

[0013] The axial flux electric machine comprises a housing and an active core comprising at least one stator and at least one rotor. The cooling plate comprises at least one internal cooling channel and is adjacent to the at least one stator.

[0014] In one embodiment of the invention, the cooling plate is manufactured by overmolding at least one stator. However, in alternative embodiments, the plate could be manufactured by a different method, such as by machining.

[0015] In one embodiment of the invention, the machine has two stators and the cooling plate makes the connection between the two stators.

[0016] The cooling plate may have a radial dimension extending to the housing, and in this case, the housing may have a portion configured to receive an outer edge portion of the cooling plate. In one embodiment of the invention, the housing is formed by a front cover and a lid. rear and the outer edge portion is formed at the junction of the front and rear covers. In this embodiment, the outer edge portion of the cooling plate has holes that coincide with holes in the housing.

[0017] In one embodiment of the invention, the cooling plate is formed in two parts with face-to-face assembly.

[0018] In one embodiment of the invention, the two cooling plate parts are mounted in a rotated and offset manner to create at least one cooling channel.

[0019] The cooling plate can also be fitted with a seal to prevent the cooling fluid from escaping.

[0020] In embodiments of the invention, the cooling plate further comprises cooling fluid inlet and outlet holes.

[0021] The cooling channel may have different shapes, such as a zigzag channel, a double C channel, a channel with a plurality of double C bends, a channel with curved zigzags, or a combination of shapes. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be described below in more detail, with reference to the attached drawings, in which:

[0023] Figure 1 is a perspective view of an axial flux electric machine according to an embodiment of the present invention, the machine being illustrated with a cutaway portion excluded for viewing the interior of the motor;

[0024] Figure 2 - is a plan view of one of the cutting planes in Figure 1;

[0025] Figure 3 is a perspective view of a portion of the internal elements - stators and cooling plate - of the axial flux electric machine according to an embodiment of the present invention;

[0026] Figure 4 - is a schematic plan view of an embodiment of the cooling plate of the axial flux electric machine according to a embodiment of the present invention, with a cross-section along line A also shown;

[0027] Figure 5 is a plan view of a cooling plate of an axial flux electric machine according to an embodiment of the present invention;

[0028] Figure 6 is a schematic illustration of a shape of a cooling channel of a cooling plate of an axial flux electric machine according to an embodiment of the present invention;

[0029] Figure 7 is a schematic illustration of a shape of a cooling channel of a cooling plate of an axial flux electric machine according to an embodiment of the present invention; and

[0030] Figure 8 is a schematic illustration of a shape of a cooling channel of a cooling plate of an axial flux electric machine according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0031] Figure 1 shows an axial flux motor according to an embodiment of the present invention.

[0032] Although the present invention is described as embodied in an electric motor, it should be understood that the solution of the present invention could equally be applied to other axial flux electrical machines such as, for example, axial flux generators.

[0033] As can be seen in Figure 1, the motor 1 comprises a housing 2 with a central through hole 3. The through hole 3 is intended to receive a shaft 4.

[0034] In the embodiment of the invention shown in the figures, the housing 2 is formed by a front cover 5 and a rear cover 6. However, it should be understood that the housing could be formed differently, for example with a central body part and two side covers.

[0035] As best illustrated in Figure 2, the motor further comprises at least one stator 7 and at least one rotor 8. The figure shows a symmetrical configuration with two stators and two rotors, but other embodiments of the present invention could present another configuration, such as, for example, a motor with a central rotor and two stators or even a motor with a stator and a rotor in a unilateral arrangement.

[0036] The axial flux machine of the present invention further comprises at least one cooling plate 9 for cooling the internal components of the motor, wherein the at least one cooling plate is arranged adjacent to the at least one stator 7.

[0037] Figure 3 shows a cross-sectional view of the cooling plate 9, in which it is possible to see internal cooling channels 10 (see also figures 5 to 8) for the passage of cooling fluid.

[0038] In a preferred embodiment of the present invention, the cooling plate 9 is injected onto the laminated stator. Also in the preferred embodiment, the cooling plate is made of aluminum injected onto the laminated steel stator.

[0039] In other embodiments of the invention, however, the plate 9 could be manufactured differently, for example from a machined component to be mounted on the stator or it could be made from another material, such as resin.

[0040] Thus, as best illustrated in figures 1 to 3, in the embodiment of the invention illustrated in the drawings, the cooling plate 9 makes the connection between the two stators 7.

[0041] Furthermore, as can be seen in figures 1 and 2, in the illustrated embodiment of the present invention, the cooling plate 9 has a radial dimension extending to the housing 2 and the housing 2 has a portion 2a configured to receive an outer edge portion 9a of the plate 9 (see figures 1a-4). In the illustrated embodiment, the portion 2a is formed in the junction region of the covers 5 and 6 of the housing 2.

[0042] In this embodiment of the invention, the outer edge portion 9a of the cooling plate 9 may have holes 9b coinciding with holes 13 present in the housing 2, allowing the fixing of the plate 9 together with the fixing of the covers 5 and 6 that form housing 2. In this embodiment, a seal can also be added, such as an o-ring or assembly paste.

[0043] In this way, the cooling plate 9 can be constructed as part of the structural assembly of the machine.

[0044] It should be noted, however, that the cooling plate could have other shapes in alternative embodiments of the invention, such as, for example, a non-circular shape that does not extend to the housing.

[0045] In the embodiment of the invention shown in the figures, the cooling plate 9 is formed in two parts 9c, 9d, face-to-face assembled (see especially Figures 2 to 5). This configuration allows the stator assembly to be combined on both sides and provides improved cooling performance by increasing the channel area. The two plate parts 9c, 9d may be identical, allowing the use of a single tool for manufacturing; however, in other embodiments, the plate parts may be different.

[0046] In this embodiment of the invention, the plate parts 9c, 9d have holes 9e for their attachment to each other. However, it should be noted that other attachment methods could be used, such as adhesive.

[0047] The cooling plate 9 may further be provided with a seal to prevent the cooling fluid from escaping.

[0048] It should be noted that in alternative embodiments of the present invention, the cooling plate 9 could be formed as a single piece or even in more parts.

[0049] Figure 4 schematically shows a cooling plate and its cross-section along section AA. As shown schematically in Figure 4, in one embodiment of the invention, the two plate parts 9c, 9d can be assembled in a rotated and offset manner to form the cooling channels 10.

[0050] However, the cooling channels 10 may have different shapes and may be manufactured in different ways.

[0051] In this sense, figure 5 shows a preferred embodiment of the invention in which the cooling channel has a zig-zag shape.

[0052] Figures 6 to 8 show different exemplary embodiments for the cooling channel of a cooling plate according to the present invention.

[0053] The figures also show cooling fluid inlet and outlet holes 11, 12 that are provided in the cooling plate.

[0054] In the exemplary embodiment of figure 6, the cooling channel 10 is formed as a double C. Thus, the cooling fluid that enters through the inlet 11 flows through the channel formed in double C and leaves through the outlet 12, after exchanging heat, cooling the internal components of the machine.

[0055] In the exemplary embodiment of Figure 7, the cooling channel 10 is formed as a channel with curved zigzags. Thus, the cooling fluid that enters through the inlet 11 flows through the channel formed in curved zigzags and exits through the outlet 12, after exchanging heat, cooling the internal components of the machine.

[0056] In the exemplary embodiment of figure 8, the cooling channel 10 is formed as a channel formed by a plurality of double C bends. Thus, the cooling fluid that enters through the inlet 11 flows through the channel formed in different double C bends and exits through the outlet 12, after exchanging heat by cooling the internal components of the machine.

[0057] It should be noted that, as mentioned above, the cooling channel 10 can take other shapes, as well as a combination of shapes.

[0058] Having described examples of embodiments of the present invention, it should be understood that the scope of the present invention encompasses other possible variations of the described inventive concept, being limited solely by the content of the claims alone, including possible equivalents.

Claims

CLAIMS 1. Axial flux electric machine (1) comprising a housing (2) and an active core comprising at least one stator (7) and at least one rotor (8), the machine being characterized in that it further comprises at least one cooling plate (9) with at least one internal cooling channel (10), the at least one cooling plate (9) being adjacent to the at least one stator (7).

2. Machine according to claim 1, characterized in that the machine has two stators (7) and at least one cooling plate (9) makes the connection between the two stators (7). Machine according to either of claims 1 or 2, characterized in that the at least one cooling plate (9) has a radial dimension extending to the housing (2) and the housing (2) has a portion (2a) configured to receive an outer edge portion (9a) of the cooling plate (9). Machine according to any one of claims 1 to 3, characterized in that the at least one cooling plate (9) is formed in two plate parts (9c, 9d) with face-to-face assembly.

5. Machine, according to claim 4, characterized by the fact that the two cooling plate parts (9c, 9d) are mounted in a rotated and offset manner to create at least one cooling channel (10). Machine according to any one of claims 1 to 5, characterized in that the at least one cooling plate (9) receives a seal to prevent the escape of cooling fluid. Machine according to any one of claims 1 to 6, characterized in that the at least one cooling plate (9) further comprises cooling fluid inlet and outlet holes (11, 12). Machine according to any one of claims 1 to 7, characterized in that the cooling channel (10) is formed as a channel with curved zigzags.

9. Cooling plate (9) for an axial flux electric machine (1) comprising a housing (2) and an active core comprising at least one stator (7) and at least one rotor (8), the plate being characterized in that comprising at least one internal cooling channel (10), the cooling plate (9) being adjacent to the at least one stator (7).

10. Cooling plate (9) according to claim 9, characterized in that it is formed in two parts (9c, 9d) with face-to-face assembly.

11. Cooling plate (9) according to either of claims 9 or 10, characterized in that the two cooling plate parts (9c, 9d) are mounted in a rotated and offset manner to create at least one cooling channel (10).

12. Cooling plate (9) according to any one of claims 9 to 11, characterized in that it has a seal to prevent the escape of cooling fluid.

13. Cooling plate (9), according to any one of claims 9 to 12, characterized in that it further comprises cooling fluid inlet and outlet holes (11, 12).

14. Cooling plate (9) according to any one of claims 9 to 13, characterized in that the cooling channel (10) is formed as a zigzag channel.

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