An oil-cooled axial flux motor

Abstract

The present application relates to a kind of oil-cooled axial flux motor, including motor housing, rotor magnetic steel, rotor yoke, rotating shaft and stator body, rotating shaft is arranged in the through-hole of stator body, rotating shaft at least one end is fixed with motor housing, stator body includes stator support and stator unit, stator support includes hollow cylindrical body and multiple spokes, which are arranged radially outside annular body, one stator unit is inserted and fixed between every two spokes, cooling oil channel is provided in stator body, and oil injection hole towards stator unit is provided on each spoke, rotor yoke is fixed in the inner wall of motor housing, rotor magnetic steel is fixed in the inner side of rotor yoke, and rotor magnetic steel is located at the two sides of stator unit.The present application can fix multiple stator units of motor while providing good cooling mode for it, and can play a cooling role in radial direction on the inside, outside middle part and other parts of winding, so that the overall heat dissipation of motor is more uniform, and the performance is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of permanent magnet synchronous drive motor technology for new energy vehicles, and more specifically, to an oil-cooled axial flux motor. Background Technology

[0002] The YASA (Yondrome-less Axial Flux Split Core) motor offers irreplaceable advantages for distributed hub drives, where the size, especially the axial dimension and weight, of the motor is extremely critical. The YASA motor, by eliminating the stator and yoke, theoretically possesses advantages such as small axial dimension and high power density, making it the preferred choice for hub drives in new energy vehicles. However, because the yoke is eliminated, the stator consists of multiple independent stator units. Structurally, these units need to be fixed, and from a heat dissipation perspective, the absence of a stator yoke makes it difficult to integrate a cooling system, leading to insufficient heat dissipation.

[0003] Currently, common fixing and heat dissipation methods for axial flux segmented core stator yokeless motors include: encapsulating the stator unit with resin material and then integrating copper tubes at the outer diameter of the stator for heat dissipation. However, this fixing and cooling method results in a long heat dissipation path, a small contact area between the cooling pipe and the stator winding, poor heat dissipation capacity, and low heat dissipation efficiency; or fixing the stator unit with structural components and opening water channels on the structural components to cool the stator. This cooling method is more efficient, but often results in inaccurate stator positioning, uneven cooling, and local hot spots caused by the structural components.

[0004] In summary, due to its unique topology, the YASA motor offers superior power density and extremely short axial length, making it highly suitable for distributed hub drives. However, effective mounting and good heat dissipation are essential for the YASA motor to achieve its full performance. Summary of the Invention

[0005] In order to solve the above-mentioned technical problems, the purpose of this invention is to provide an oil-cooled axial flux motor with strong heat dissipation capacity and good performance.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0007] An oil-cooled axial flux motor includes a motor housing, rotor magnets, a rotor yoke, a shaft, and a stator. The stator has a through hole in its center. The shaft is disposed within the through hole and rotatably connected to the stator via a bearing. At least one end of the shaft is fixed to the motor housing. The stator includes a stator support and stator units. The stator support comprises a hollow cylindrical body and multiple spokes radially arranged on the outer side of the annular body. A stator unit is inserted and fixed between every two spokes. The stator has cooling oil channels, and each spoke has an oil spray hole facing the stator unit. The rotor yoke is fixed to the inner wall of the motor housing, and the rotor magnets are fixed to the inner side of the rotor yoke, located on both sides of the stator units.

[0008] As a preferred embodiment, the hollow cylindrical body is a stator structural component, and stator fixing components are fixed at both ends of the stator structural component along the axial direction. The stator fixing component includes a fixing ring and multiple fixing spokes. The stator structural component is provided with an annular oil passage, and the fixing spokes are provided with radial oil passages that communicate with the oil injection holes, and the radial oil passages are connected to the annular oil passages.

[0009] As a preferred embodiment, the oil injection holes are in multiple sets, respectively located on the inner side of the spokes of the fixing member near the pivot and away from the pivot. Each set of oil injection holes includes two through holes that are staggered circumferentially and radially.

[0010] As a preferred embodiment, oil holes are respectively provided on both sides of the end of the fixing member spoke away from the rotating shaft along the circumferential direction.

[0011] As a preferred embodiment, stator oil baffles are fixed on both sides of the stator unit, and the two oil baffles are connected by a stator oil baffle ring to form an oil cavity.

[0012] As a preferred embodiment, the fastener spokes are further provided with fixing wings on both sides along the circumferential direction for fixing the stator unit.

[0013] As a preferred embodiment, the stator unit includes a stator core and a concentrated winding wound around the stator core. The stator core is inserted between two fixed spokes, and the fixed side wings of the fixed spokes are inserted between the inner side of the end face of the stator core and the concentrated winding.

[0014] As a preferred embodiment, the stator core includes two trapezoidal lugs and a longitudinal support plate that is vertically and fixedly connected to the two trapezoidal lugs. The centralized winding is wound around the longitudinal support plate and located between the two trapezoidal lugs.

[0015] As a preferred embodiment, the two ends of the centralized winding are stepped, and the fixed side wing is inserted into the groove formed by the trapezoidal baffle of the stator core and the end of the centralized winding.

[0016] As a preferred embodiment, the length of the fixed side wing is less than the length of the fixing spoke, and the thickness of the fixed side wing is 12% to 50% of the thickness of the fixing spoke.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] The motor of the present invention, by setting a stator support and opening oil channels and oil injection holes on the stator support, fixes multiple stator units of the motor while providing them with a good cooling method. It can also cool multiple parts such as the inner side and the middle of the outer side of the winding in the radial direction, so that the overall heat dissipation of the motor is more uniform, thereby greatly improving the performance. Attached Figure Description

[0019] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute a limitation thereof.

[0020] Figure 1 This is a schematic cross-sectional view of the motor of the present invention;

[0021] Figure 2 This is a schematic diagram of the stator body of the motor of the present invention;

[0022] Figure 3 This is a schematic diagram of the end face structure of the stator structure component of the present invention;

[0023] Figure 4 This is a cross-sectional structural diagram of the stator structure of the present invention;

[0024] Figure 5 This is a three-dimensional structural diagram of the stator fixing member of the present invention;

[0025] Figure 6 This is a cross-sectional structural diagram of the stator fastener of the present invention;

[0026] Figure 7 This is a front structural diagram of the stator fastener of the present invention;

[0027] Figure 8 This is a schematic diagram of the stator core structure of the present invention;

[0028] Figure 9 This is a schematic diagram of the structure of two adjacent stator units of the present invention;

[0029] Figure 10 This is a schematic diagram of the structure of the present invention, in which a spoke is inserted into two adjacent stator units;

[0030] Figure 11 This is a schematic diagram showing the flow direction of the cooling oil in the motor of the present invention.

[0031] The attached diagram is labeled as follows: 1. Front rotor magnet; 2. Front rotor yoke; 3. Front end cover; 4. Side housing; 5. Rear end cover; 6. Rear rotor yoke; 7. Rear rotor magnet; 8. Stator structural component; 9. Bearing; 10. Shaft; 11. Rear stator fixing component; 12. Stator oil baffle; 13. Stator unit; 14. Front stator fixing component; 13-1. Stator core; 13-2. Concentrated winding; 11-1. Fixing component spokes; 11-2. Fixing side wing; 11-3. Radial oil passage; 11-4. Oil hole; 11-5. Through hole; 8-1. Upper oil inlet hole; 8-2. Lower oil inlet hole; 8-3. Upper through oil groove; 8-4. Lower through oil groove. Detailed Implementation

[0032] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0033] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0034] Furthermore, in the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more, unless explicitly defined otherwise.

[0036] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0037] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0038] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0039] like Figure 1 As shown, an oil-cooled axial flux motor includes a motor housing, rotor magnets, rotor yoke, rotating shaft 10, and stator body. The stator body has a through hole in the middle. The rotating shaft 10 is disposed in the through hole of the stator body and is rotatably connected to the stator body through a bearing 9. At least one end of the rotating shaft 10 is fixed to the motor housing. The stator body includes a stator support member and a stator unit 13. The stator support member includes a hollow cylindrical body and multiple spokes arranged radially on the outside of the annular body. A stator unit 13 is inserted and fixed between every two spokes. The included angle between two adjacent spokes is equal to the slot pitch angle of the stator unit.

[0040] The stator body is provided with cooling oil channels, and each spoke is provided with an oil spray hole facing the stator unit. Stator oil baffles are fixed on both sides of the stator unit, and the two oil baffles are connected by stator oil baffle ring 12 to form an oil cavity. The rotor yoke is fixed to the inner wall of the motor housing, the rotor magnet is fixed to the inner side of the rotor yoke, and the rotor magnet is located on both sides of the stator unit 13.

[0041] The motor housing includes a side housing 4, a front cover 3, and a rear cover 5; the middle of the rear cover 5 is fixed to one end of the rotating shaft 10, the outer edge of the rear cover 5 is fixed to one side of the side housing 4, and the outer edge of the front cover 3 is fixed to the other side of the side housing 4; the rotor yoke includes a front rotor yoke 2 fixed to the front cover 3 and a rear rotor yoke 6 fixed to the rear cover 5; the rotor magnets include a front rotor magnet 1 fixed to the front rotor yoke 2 and a rear rotor magnet 7 fixed to the rear rotor yoke 6.

[0042] like Figures 2 to 5 As shown, the hollow cylindrical body is a stator structural component 8. Stator fixing components are fixed at both ends of the stator structural component 8 along the axial direction. The stator fixing component includes a fixing ring and multiple fixing spokes 11-1. The stator structural component 8 is provided with an annular oil passage. The fixing spokes 11-1 are provided with a radial oil passage 11-3 that communicates with the oil injection hole, and the radial oil passage 11-3 communicates with the annular oil passage.

[0043] The end face of the stator structural component 8 is also provided with an upper oil inlet hole 8-1 and a lower oil inlet hole 8-2. The annular oil passage includes an upper oil channel 8-3 that communicates with the upper oil inlet hole 8-1 and a lower oil channel 8-4 that communicates with the lower oil inlet hole 8-2. The upper oil channel 8-3 and the lower oil channel 8-4 are respectively connected to the inner radial oil passage 11-3 of the fixing spokes 11-1 of the two stator fixing components.

[0044] The fixed spoke 11-1 has multiple sets of oil injection holes, respectively located on the inner side of the fixed spoke 11-1 near the pivot and away from the pivot. Each set of oil injection holes includes two through holes 11-5 that are staggered circumferentially and radially. Oil holes 11-4 (e.g., oil holes 11-4) are respectively opened on both sides of the end of the fixed spoke 11-1 away from the pivot 10 along the circumferential direction. Figure 4 and Figure 5 (As shown).

[0045] Two opposing fixing spokes 11-1 cool the two ends of the stator unit axially, and their staggered arrangement allows them to spray oil onto the windings of adjacent single stator units; the oil holes 11-4 of the fixing spokes 11-1 allow oil to be sprayed onto the windings at the outer diameter of the stator.

[0046] like Figure 9As shown, the cooling oil flow path in the motor of the present invention is as follows: the cooling oil enters the annular oil channel of the stator structure 8, and a portion of the cooling oil is sprayed from the through hole 11-5 of the fixed spoke 11-1 to the winding. Depending on the motor placement, the cooling oil sprayed onto the upper half of the winding is drawn into the inner oil cavity near the shaft under the influence of gravity, and flows down along the oil cavity, passing through the winding at the inner diameter of the stator, and carrying away its heat; the cooling oil sprayed onto the lower half of the winding is drawn into the outer diameter oil cavity under the influence of gravity, and flows down along the outer diameter oil cavity, passing through the winding at the outer diameter of the stator, and carrying away its heat; another portion of the cooling oil is sprayed from both sides of the outer diameter of the fixed spoke 11-1 to the outer diameter winding, and the oil in the upper half of the outer diameter winding flows out from the outer diameter oil cavity under the influence of gravity.

[0047] The fastener spokes 11-1 are also provided with fastening side wings 11-2 on both sides along the circumferential direction for fixing the stator unit 13 (e.g., ...). Figure 4 (As shown).

[0048] like Figures 6 to 8 As shown, the stator unit 13 includes a stator core 13-1 and a concentrated winding 13-2 wound on the stator core 13-1. The stator core 13-1 is inserted between two fixing spokes 11-1, and the fixing side wing 11-2 of the fixing spoke 11-1 is inserted between the inner side of the end face of the stator core 13-1 and the concentrated winding 13-2.

[0049] The stator core 13-1 includes two trapezoidal side lugs and a longitudinal support plate that is vertically and fixedly connected to the two trapezoidal side lugs. The concentrated winding 13-2 is wound around the longitudinal support plate and located between the two trapezoidal side lugs. The two ends of the concentrated winding 13-2 are stepped, and the fixed side wing 11-2 is engaged in the groove formed by the trapezoidal baffle of the stator core 13-1 and the end of the concentrated winding 13-2.

[0050] To ensure the insertion of the fixed side wing 11-2, when the concentrated winding of a single stator unit is wound from the inside to the outside, the number of turns in each layer decreases by one or several turns, and a certain space is symmetrically left at the axial end of the stator core to form a stepped shape.

[0051] The length of the fixed side wing 11-2 is less than the length of the fixing spoke 11-1, and the thickness of the fixed side wing 11-2 is 12% to 50% of the thickness of the fixing spoke 11-1.

[0052] The structure of the motor of the present invention changes the common fixing method of the current axial flux segmented iron core stator yokeless motor (by potting the entire stator unit with resin material), thereby overcoming the problems of difficult disassembly, maintenance and reuse of the potted motor; at the same time, the stator support component used in the motor of the present invention is accurately positioned, which can reduce the harmonics of the air gap magnetic field of the motor, reduce motor loss, and improve a series of performance such as NVH.

[0053] This invention proposes an oil-cooled axial flux motor design, which can provide a good fixing and cooling method for the multi-stator unit of the YASA motor, ultimately achieving the goal of improving the output performance of the YASA motor.

[0054] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0055] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. An oil-cooled axial flux motor, characterized in that, The stator includes a motor housing, rotor magnets, rotor yoke, shaft (10), and stator body. The stator body has a through hole in the middle. The shaft (10) is located in the through hole of the stator body and is rotatably connected to the stator body through a bearing (9). At least one end of the shaft (10) is fixed to the motor housing. The stator body includes a stator support and a stator unit (13). The stator support includes a hollow cylindrical body and multiple spokes arranged radially on the outside of the annular body. A stator unit (13) is inserted and fixed between every two spokes. The stator body has a cooling oil passage and an oil spray hole facing the stator unit on each spoke. The rotor yoke is fixed to the inner wall of the motor housing. The rotor magnets are fixed to the inner side of the rotor yoke. The rotor magnets are located on both sides of the stator unit (13). The hollow cylindrical body is a stator structural component (8). The stator structural component (8) has stator fixing components fixed at both ends of its axial direction. The stator fixing component includes a fixing ring and multiple fixing spokes (11-1). The stator structural component (8) has an annular oil passage. The fixing spokes (11-1) have radial oil passages (11-3) that communicate with the oil injection hole. The radial oil passages (11-3) communicate with the annular oil passages. The fixing spokes (11-1) are also provided with fixing wings (11-2) on both sides along the circumferential direction for fixing the stator unit (13). The stator unit (13) includes a stator core (13-1) and a concentrated winding (13-2) wound on the stator core (13-1). The stator core (13-1) is inserted between two fixed spokes (11-1), and the fixed side wings (11-2) of the fixed spokes (11-1) are inserted between the inner side of the end face of the stator core (13-1) and the concentrated winding (13-2).

2. The oil-cooled axial flux motor according to claim 1, characterized in that, The oil injection holes are in multiple sets, respectively located on the inner side of the fixed part spoke (11-1) near the rotating shaft and away from the rotating shaft. Each set of oil injection holes includes two through holes (11-5) that are staggered in both circumference and radial direction.

3. The oil-cooled axial flux motor according to claim 1, characterized in that, Oil holes (11-4) are respectively opened on both sides of the end of the fixed component spoke (11-1) away from the rotating shaft (10) along the circumferential direction.

4. The oil-cooled axial flux motor according to claim 1, characterized in that, The stator unit is fixed with stator oil baffles on both sides, and the two oil baffles are connected by a stator oil baffle ring (12) to form an oil cavity.

5. The oil-cooled axial flux motor according to claim 1, characterized in that, The stator core (13-1) includes two trapezoidal side lugs and a longitudinal support plate that is vertically fixed to the two trapezoidal side lugs. The centralized winding (13-2) is wound around the longitudinal support plate and is located between the two trapezoidal side lugs.

6. The oil-cooled axial flux motor according to claim 5, characterized in that, The two ends of the centralized winding (13-2) are stepped, and the fixed side wing (11-2) is inserted into the groove formed by the trapezoidal baffle of the stator core (13-1) and the end of the centralized winding (13-2).

7. The oil-cooled axial flux motor according to claim 1, characterized in that, The length of the fixed side wing (11-2) is less than the length of the fixing spoke (11-1), and the thickness of the fixed side wing (11-2) is 12% to 50% of the thickness of the fixing spoke (11-1).

Images