Axial flux motor cooling structure

Abstract

The present invention discloses an axial flux motor cooling structure, including a cooling structure channel and a sealed end cover installed in the stator core, the two cooperate to form a cooling cavity, and the winding coil is fixed inside the cooling cavity. A channel guide structure and an end cover guide structure are provided in the cooling cavity. The channel guide structure includes a liquid ejection structure, wing-shaped guide blades, a sub-cavity separation structure and an outlet guide structure. The end cover guide structure includes a gap guide baffle, a diversion pressure plate and an outlet return structure. After the cooling liquid enters the sealed cooling cavity through the flow channel inlet, it forms a directional high-speed flow inside the cooling cavity, and is discharged from the flow channel outlet after achieving efficient heat exchange with the winding coil. The present invention significantly improves the cooling efficiency and temperature uniformity of the winding coil through the integration of the immersion cooling structure and the design of the guide system path. At the same time, the compact structural design is conducive to improving the motor power density and system integration.

Description

Technical Field

[0001] The invention relates to cooling of an axial flux motor, and in particular to a cooling structure of an axial flux motor. Background Art

[0002] With the increasing demand for high-performance, lightweight drive systems, axial-flux motors are developing towards higher torque density and higher current density. This trend significantly increases losses in the motor's internal windings, and the problem of winding temperature rise is becoming increasingly prominent, becoming a key factor limiting its continuous operating capability, thermal stability, and lifespan. Especially under high-load operating conditions, if the winding heat cannot be dissipated effectively and promptly, it will lead to insulation aging, increased risk of demagnetization, and even thermal runaway, seriously affecting the reliability and safety of the system. Therefore, how to effectively improve winding cooling efficiency within a limited space has become a critical technical issue that needs to be addressed in the current design of axial-flux motors.

[0003] Based on current applications and research progress, existing technologies typically dissipate heat from the winding coils of axial flux permanent magnet motors using natural cooling, air cooling, or simple water jacket cooling. These cooling structures primarily rely on stator periphery cooling, preventing the cooling medium from effectively reaching the winding coil area, resulting in high thermal resistance and limited heat dissipation efficiency. Additionally, some studies have attempted to improve cooling efficiency through immersion oil cooling, but the sealing designs of currently available implementations are limited in functionality and structure, and can easily increase the motor's size and affect the air gap magnetic circuit design and performance stability.

[0004] Existing technologies have made various attempts to cool axial flux permanent magnet motors, but the following key technical bottlenecks still exist, restricting the improvement of motor power density and system reliability:

[0005] (1) Low flow efficiency. In existing immersion cooling structures, there are often blind spots in the flow path of the cooling fluid near the windings, resulting in uneven distribution of the coolant flow rate and poor local cooling effect. At the same time, the inner wall roughness and narrow flow channels caused by the casting process will further aggravate hydraulic losses, requiring the use of high-lift cooling pumps to maintain flow, resulting in a significant increase in system energy consumption and noise.

[0006] (2) Poor cooling uniformity, prone to local thermal runaway. Existing technologies make it difficult to achieve heat load matching. The cooling points are concentrated at the outlet, and the coolant has already heated up significantly by the time it reaches the target area, making it impossible to cool the windings at the rear end of the flow direction. In addition, the existing flow channel is basically a single channel, and the internal fluid is relatively inefficient in cooling the hot spots.

[0007] (3) The air gap size is limited, which affects the optimization of the magnetic circuit. Some existing solutions require the introduction of a sealing cover plate in the air gap between the stator and rotor to achieve coolant sealing. This type of structure occupies the air gap space, limiting the compression and precise control of the air gap size. The electromagnetic performance of the axial flux motor is extremely sensitive to the air gap thickness. A slight increase in the air gap will lead to a decrease in magnetic flux density, a decrease in electromagnetic performance, an increase in assembly errors and the risk of high-speed operation, which limits the realization of high power density of axial flux permanent magnet motors.

[0008] (4) System complexity and maintenance costs. Traditional solutions rely on external high-power pumps and complex piping, resulting in pressure loss, leakage risks, and installation space occupation. Closed water cooling systems have strict requirements on cooling media, and maintenance costs are significantly higher than open systems. Summary of the Invention

[0009] An object of the present invention is to provide an axial flux motor cooling structure that solves one of the technical problems in the related art at least to a certain extent.

[0010] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0011] An axial flux motor cooling structure comprises a cooling structure channel and a cooling structure end cover fixed on one axial side of the cooling structure channel, wherein the cooling structure end cover and the cooling structure end cover are sealed and matched to form a cooling cavity;

[0012] The cooling structure channel is periodically arranged along the circumferential direction with stator core mounting holes that match the shape of the stator core, and the cooling structure channel is matched with the stator core by axial plugging;

[0013] The winding coil is fixed in the cooling cavity, and its lead wire passes through the side of the cooling structure channel.

[0014] Furthermore, the cooling structure channel has an outer circular wall surface, an inner circular wall surface and a plurality of stator core tooth wall surfaces; sealing grooves and sealing rings are provided on the inner and outer circular surfaces of the mating surfaces of the cooling structure channel and the cooling structure end cover and the stator core tooth wall surfaces, and a sealed cooling cavity is formed by tightly fitting the fixing assembly;

[0015] The winding coil is inserted into the cooling structure channel from the axial direction through the wall surface of the stator core tooth portion.

[0016] Furthermore, the bottom surface of the cooling structure channel is periodically arranged along the circumferential direction and is respectively provided with a plurality of flow channel inlets, channel guide structures and flow channel outlets;

[0017] The surface of the cooling structure end cover is provided with a plurality of end cover guide structures periodically arranged along the circumferential direction;

[0018] The cooling liquid flows into the sealed cooling cavity through the flow channel inlet, and the flow and heat dissipation performance are enhanced under the action of the channel guide structure and the end cover guide structure. After direct contact with the winding coil to achieve heat exchange, it flows out of the cooling cavity from the flow channel outlet, realizing efficient cooling of the winding coil.

[0019] Furthermore, the channel guide structure includes a liquid ejection structure arranged at each flow channel inlet on the bottom surface of the cooling structure channel. The ejection direction of the liquid ejection structure is radially outward and the outlet cross-section is a tapered Venturi structure, which increases the initial kinetic energy of the liquid flowing into the flow channel inlet.

[0020] Furthermore, the channel guide structure also includes wing-shaped guide blades whose distribution positions correspond one-to-one to the liquid ejection structure, and whose axial cross-section presents a wing-shaped profile with a continuous variable curvature; the leading edge curvature radius of the wing-shaped guide blade is large and aligned with the axis of the liquid ejection structure, reducing the risk of fluid flow separation; the middle to the tail of the wing-shaped guide blade gradually flattens, pointing to the gap between the winding coils, guiding the cooling liquid to flow into the gap between the winding coils in a directionally accelerated manner, thereby achieving efficient heat exchange.

[0021] Furthermore, the channel guide structure also includes a sub-cavity separation structure arranged at the axis of each winding coil and extending radially to the winding coil, which divides the sealed cooling cavity into multiple independent sub-cavities distributed on both sides of the wing-shaped guide blades, blocks the non-directional cross-flow between the sub-cavities, and improves the coolant flow rate and heat exchange efficiency by suppressing the circumferential pressure balance.

[0022] Furthermore, a groove is opened inside the sub-cavity partition structure for leading out the lead wires of the winding coil.

[0023] Furthermore, the channel guide structure also includes an outlet guide structure provided at each flow channel outlet on the bottom surface of the cooling structure channel, which is composed of two arc-shaped guide surfaces symmetrically arranged along the radial axis, intersecting at the inner ends and gradually expanding toward the outer ends, and its axial cross-section presents a trumpet-shaped profile with continuous variable curvature;

[0024] The inner end of the outlet drainage structure is aligned with the central axis of the gap between two adjacent winding coils, and the cooling fluid is guided to the ends of the winding coils through the arc-shaped guide surface to improve the heat exchange efficiency; the curvature direction of the arc-shaped guide surface is the same as the curvature direction of the ends of the adjacent winding coils, and the curvature of the arc-shaped guide surface is smaller than the curvature of the ends of the winding coils;

[0025] The outer end opening of the outlet drainage structure is trumpet-shaped, surrounding both sides of the flow channel outlet and having a certain gap with the inner wall of the outer circle of the cooling structure channel, thereby constructing a diffusion-type Venturi structure; this diffusion-type Venturi structure can realize a gradual slowing down of the flow velocity when the cooling fluid leaves the sealed cavity, and effectively convert part of the kinetic energy into static pressure, thereby improving the pressure recovery capacity at the flow channel outlet, and facilitating the formation of a stable flow pressure gradient, thereby reducing local turbulence and flow losses.

[0026] Furthermore, the end cover flow guide structure includes a plurality of gap flow guide baffles, flow diversion and compression plates and outlet return flow structures that are periodically arranged along the circumferential direction on the bottom surface of the cooling structure end cover;

[0027] The gap drainage baffle is distributed between every two stator mounting holes and extends radially. Its top is pointed and can be tightly inserted between two winding coils. It can limit the flow between the gaps of two adjacent winding coils to the space between the winding coils, preventing overflow and weakening the cooling effect.

[0028] The flow splitting and pressing plates are distributed on both sides of the gap drainage baffle, dividing the cooling fluid between the winding coil and the cooling structure end cover into multiple channels for flow, while also playing a role in pressing and fixing the winding coil;

[0029] The outlet reflux structure has a curved wall reflux shape and is respectively arranged on the radial inner and outer sides of each stator mounting hole, cooperating with the cooling structure channel to form a reflux, thereby achieving enhanced cooling of the local hot spots of the winding coil.

[0030] Furthermore, an axial expansion groove is provided on the outer periphery of the stator core tooth wall of the cooling structure channel for cooling the inner side of the winding coil to prevent local overheating caused by close fitting.

[0031] The beneficial effects of the present invention are:

[0032] (1) Improve flow channel efficiency and heat exchange capacity

[0033] The wing-shaped guide vanes in this invention optimize fluid dynamics through their wing-shaped cross-section flow channel design. The wing-shaped structure reduces the risk of boundary layer separation and turbulent losses. Furthermore, the Venturi and Bernoulli effects are leveraged to enhance local flow velocity, addressing backflow issues. Combined with low-pressure zone ejection technology, this creates a directional negative pressure in critical heat-load areas, actively guiding the coolant toward high-temperature points.

[0034] (2) Non-air-gap intrusion sealing structure and lightweight structure advantages

[0035] The cooling skeleton structure proposed in this invention utilizes a non-air-gap-intrusive sealing method, placing the sealing structure outside the air gap. This avoids the encroachment of traditional sealing structures on the motor's air gap thickness, ensuring the stability of the motor's air gap dimensions and the consistency of its electromagnetic performance. Furthermore, the proposed cooling skeleton structure utilizes lightweight materials and an integrated structural layout, significantly reducing the cooling system weight while improving the cooling efficiency of the stator windings. This further enhances the power density and system integration of the axial flux permanent magnet motor.

[0036] (3) Structural integration and reliability enhancement

[0037] The present invention uses additive manufacturing technology (or injection molding technology) to embed the wing flow channel and the ejection cavity into the cooling structure body, eliminating the connection points of the split structure implementation and reducing the risk of leakage; through the optimization of the flow channel topology, the winding coil is embedded to achieve a compact layout, and the installation space requirement is reduced compared to traditional solutions, which is suitable for the narrow thermal management space of high-power density motors and engines. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is an exploded view of the main components of the present invention;

[0039] Figure 2 This is an axial view of the cooling structure channel and the cooling structure end cover in the present invention after being combined;

[0040] Figure 3 This is a bottom view of the cooling structure channel and the cooling structure end cover in the present invention after being combined;

[0041] Figure 4 This is a schematic diagram of the combination of the cooling structure channel and the winding coil in the present invention;

[0042] Figure 5 for Figure 4 Enlarged view of point A in the middle;

[0043] Figure 6 Schematic diagram of the cooling structure end cover of the present invention;

[0044] Figure 7 for Figure 6 Enlarged view of point B in the middle;

[0045] Figure 8 Graph showing design parameters for the inlet drainage structure of the present invention;

[0046] Figure 9 Schematic diagram of the cooling liquid flow path in the present invention.

[0047] The accompanying drawings are for illustrative purposes only and are not to be construed as limiting the present invention. To better illustrate the present embodiment, certain components of the accompanying drawings may be omitted, enlarged, or reduced in size, and do not represent the dimensions of actual products. It is understandable to those skilled in the art that certain well-known structures and their descriptions may be omitted from the accompanying drawings. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0049] Example 1:

[0050] like Figures 1 to 9As shown, this embodiment discloses an axial flux motor cooling structure, including a cooling structure channel 1, a cooling structure end cover 2, a sealing ring assembly 9, a winding coil 3 and a stator core 5.

[0051] The cooling channel 1 is inserted axially into the stator core teeth 501 through the stator core mounting holes 101, which are periodically arranged along the circumference of the stator core, and fits tightly against the stator core 5. The mating surface 102 at the bottom of the cooling channel 1 aligns closely with the upper surface 502 of the stator core yoke. The winding coil 3 is axially inserted into the cooling channel 1 through the core mounting holes 101 and is compressed and secured within the cooling cavity formed by the cooling channel 1 and the cooling structure end cover 2.

[0052] The cooling structure channel 1 and cooling structure end cap 2 can be formed from insulating materials through additive manufacturing (or injection molding) and are tightly secured axially by multiple inner ring fixing screw holes 41 and outer ring fixing screw holes 42. To enhance the sealing performance of the cooling cavities within the two, a corresponding sealing structure is provided at the connection between the cooling structure channel 1 and the cooling structure end cap 2, which tightly cooperates with the sealing ring assembly 9.

[0053] The cooling structure channel 1 has an outer circular wall surface, an inner circular wall surface and multiple stator core tooth wall surfaces; a sealing structure is provided at the inner circle, outer circle and stator core tooth wall surfaces of the matching surface between the cooling structure channel and the cooling structure end cover.

[0054] The sealing structure specifically includes: an inner wall sealing groove 91 and an inner wall sealing rubber ring 911 installed in cooperation with it; an outer wall sealing groove 92 and an outer wall sealing rubber ring 921 installed in cooperation with it; a tooth top sealing groove 93 set on the wall surface of each stator core tooth, and a tooth top sealing rubber ring 931 installed in cooperation with it.

[0055] The sealing structure also includes the following components provided on the cooling structure end cover 2: an inner sealing groove 95 of the end cover (cooperating with the inner wall sealing rubber ring 911), an outer sealing groove 94 of the end cover (cooperating with the outer wall sealing rubber ring 921), and a tooth top sealing groove 96 of the end cover (cooperating with the tooth top sealing rubber ring 931).

[0056] The cooling channel 1 is periodically arranged along its circumference, with a cooling circulation channel inlet 5 (located radially inward of the channel's bottom surface), a channel guide structure, and a cooling circulation channel outlet 6 (located radially outward of the channel's bottom surface). The channel guide structure includes a liquid ejection structure 51, wing-shaped guide vanes 10, a sub-cavity partitioning structure 11, and an outlet guide structure 13, all of which are arranged periodically.

[0057] The cooling structure end cover 2 is provided with an end cover guide structure periodically arranged along the circumferential direction, specifically including an outlet reflux structure 20, a gap guide baffle 21 and a diversion pressing plate 22, all of which are periodically arranged.

[0058] The cooling liquid flows in through the cooling circulation channel inlet 5, is guided by the end cover guide structure and the channel guide structure, and flows out from the cooling circulation channel outlet 6. During this process, the winding coil 3 is in direct contact with the cooling liquid entering the cooling chamber, achieving sufficient cooling of the winding coil.

[0059] The following introduces the specific details and functions of the channel diversion structure and the end cover diversion structure:

[0060] The channel flow-guiding structure includes a sub-cavity partitioning structure 11, located between each winding coil and the outer wall of the cooling channel. This structure secures the winding coils 3 and simultaneously divides the sealed cooling chamber into multiple independent sub-cavities, preventing non-directional cross-flow between the sub-cavities. This improves coolant flow rate and heat exchange efficiency by suppressing circumferential pressure equalization. In this embodiment, slots are provided within the sub-cavity partitioning structure 11 for connecting the coil winding lead wires 31 in parallel or in series to the inner phase winding terminations 32 (ultimately leading out through the three-phase winding lead terminals 33).

[0061] In each sub-cavity separated by the sub-cavity partition structure 11 and the winding coil 3, a liquid ejection structure 51 is arranged at each flow channel inlet on the bottom surface of the cooling structure channel. The liquid ejection direction is radially outward and the outlet cross-section is a tapered Venturi structure, which increases the initial kinetic energy of the liquid flowing into the flow channel inlet.

[0062] The wing-shaped guide blades 10 are arranged on the radial inner circumference of the cooling structure channel, corresponding one to one with the liquid ejection structure 51, and their axial cross-sections present a wing-shaped profile with a continuous variable curvature.

[0063] The leading edge (inner end) of the wing-shaped guide vane has a large radius of curvature and is aligned with the axis of the liquid ejection structure. The trailing end (outer end) of the wing-shaped guide vane 10 points toward the gap between the two winding coils, guiding the cooling liquid to flow into the gap in a directional and accelerated manner. Simultaneously, low-pressure areas are formed at the impact points near the inner ends on both sides of the vane, driving the cooling liquid in the nearby cavity forward.

[0064] based on Figure 8 The design parameters shown, the design parameters of the liquid ejection structure 51 in the channel guide structure and the design of the wing-shaped guide blades 10 are based on the following design method:

[0065] 1) The radius of the flow channel entrance The leading edge radius of the airfoil blade The relationship between can be expressed as:

[0066]

[0067] in, is the distance between the inlet edge and the leading edge of the wing blade (in this embodiment Take 0, the two are in contact).

[0068] 2) Opening angle of the liquid ejection structure Chord length of airfoil blade and the leading edge radius of the airfoil blade It can be designed to satisfy the following relationship:

[0069]

[0070] 3) Radius of the leading edge of the airfoil blade and chord length The relationship can be designed to satisfy the following relationship:

[0071]

[0072] 4) Wing blade thickness and chord length The relationship satisfies:

[0073]

[0074] in, is the thickness ratio of the airfoil blade, which is 0.15 in this example.

[0075] 5) According to Bernoulli's equation, the inlet pressure and speed , pressure in the middle of the airfoil blade and speed and outlet pressure and speed The relationship satisfies:

[0076]

[0077] in, is the density of the fluid (in kg / m 3 ).

[0078] After the inlet fluid passes through the head of the wing-shaped blade and reaches the middle, the fluid velocity increases and the pressure decreases to form a low-pressure area. Gradually increases to ,correspond Reduce to When the fluid flows from the middle of the wing blade to the tail, the curvature of the wing surface is small, and the low-pressure area sucks the fluid in the surrounding chamber and flows radially toward the outlet. At this time, a high-pressure accumulation area is formed at the outlet, pressing the fluid into the gap between the two winding coils. Gradually decrease to ,correspond Increase to Therefore, the thickness of the airfoil blade is and outlet pressure and speed The relationship is expressed as

[0079]

[0080]

[0081] Optimizing the structural dimensions based on the relationships between the parameters described in the above formula can yield a design with excellent flow diversion performance. In practice, further optimization and adjustments can be made based on specific application scenarios and requirements.

[0082] The liquid ejection structure 51 and the wing-shaped guide vanes 10 in the above-mentioned channel guide structure are mainly responsible for improving the cooling effect of the winding coil gap.

[0083] The channel guide structure forms a high-speed-low-pressure synergistic effect through the coordinated cooperation of the liquid ejection structure, the wing-shaped guide vanes and the sub-cavity separation structure. The cooling liquid flowing in from the flow channel inlet is accelerated by the liquid ejection structure to form a low-pressure area at the leading edge of the wing-shaped guide vanes, and is guided and accelerated by the wing-shaped guide vanes to be injected into the winding gap. At the same time, the secondary flow of the cooling liquid in the cavities on both sides of the wing-shaped guide vanes along the drainage direction is strengthened, thereby enhancing the directionality and heat exchange efficiency of the cooling liquid flow.

[0084] The channel guide structure also includes an outlet drainage structure 13 arranged on the radial outer circumference of the cooling structure channel. It is composed of two arc-shaped guide surfaces arranged symmetrically along the radial axis, intersecting at the inner ends and gradually expanding toward the outer ends. The axial cross-section is a trumpet-shaped profile with a continuously variable curvature, with a smaller radial inner end and a larger outer end. The outer end of the outlet drainage structure 13 corresponds one-to-one with the outlet 6 of the cooling circulation flow channel, and the inner end of the outlet drainage structure is located between the two winding coils 3. The curvature direction of the arc-shaped guide surface is the same as the curvature direction of the adjacent winding coil ends, and the curvature of the arc-shaped guide surface is smaller than the curvature of the winding coil ends. The cooling fluid passing through the gap between the winding coils flows along the arc-shaped guide surface to both sides, cooling the radial outer end area of ​​the winding coil.

[0085] The trumpet-shaped opening at the outer end of the outlet drainage structure 13 surrounds the cooling circulation channel outlet 6 and is spaced a certain distance from the inner wall of the outer circle of the cooling structure channel, thereby forming a diffuser-type Venturi structure. This diffuser-type Venturi structure gradually slows the flow rate of the cooling fluid as it leaves the sealed cavity, effectively converting some of its kinetic energy into static pressure, improving the pressure recovery capability at the channel outlet and facilitating the formation of a stable flow pressure gradient, thereby reducing local turbulence and flow losses.

[0086] In order to further enhance the cooling effect on the top and radially outer ends of the winding coil, the end cover guide structure provided on the cooling structure end cover 2 has the following features:

[0087] The gap diversion baffle 21 included in the end cover guide structure extends radially, and its top is pointed to be tightly inserted between two winding coils. It can limit the flow in the gap between two adjacent winding coils to between the winding coils, preventing overflow and weakening of the cooling effect.

[0088] The diverter and clamping plates 22 are respectively located on both sides of the gap diversion baffle 21. The diverter and clamping plates 22 can not only compress the corresponding winding coil 3, but also regulate the flow state of the cooling fluid between the winding coil 3 and the cooling structure end cover 2. Dividing it into multi-channel flow can reduce liquid flow loss and enhance heat exchange capacity.

[0089] The outlet return flow structures 20 are respectively located radially outside the winding coils, and both sides thereof are curved wall return flow shapes (with smaller hydraulic loss), for forming return flow to cool the radially outer end regions of the winding coils.

[0090] The working principle of the present invention is as follows:

[0091] Through innovative immersion cooling structure integration methods and optimized design of the flow guide system path, the cooling efficiency and temperature uniformity of the winding coil are significantly improved.

[0092] The cooling structure seals the winding coil inside the cooling cavity, improving the cooling efficiency of the winding coil through the efficient circulation of the cooling liquid; at the same time, the non-air gap intrusive design of the cooling structure and the integrated installation method based on hole plug-in ensure that the rotor magnetic circuit design of the axial flux motor is not affected.

[0093] The optimized design of the flow guide system path optimizes the flow path of the cooling liquid into three parts: gap flow, end flow and top flow, while achieving targeted and efficient heat dissipation of the high-temperature areas in the gap, end and top of the winding coil.

[0094] The top flow near the end cover of the cooling structure is to enhance the heat exchange between the upper winding coil and the cooling liquid, such as Figure 9 In (a), the flow of the cooling liquid is indicated by the dotted arrows. The cooling medium enters the structure through the cooling circulation channel inlet 5, is accelerated by the liquid ejection structure 51, and enters the top area of ​​the winding coil 3. In this area, the gap diversion baffle 21 and the diversion and compression plate 22 divide it into four flow channels, minimizing overall flow losses.

[0095] When the cooling medium flows to the vicinity of the cooling outlet, the outlet reflux structure 20 has a curved wall reflux shape with small hydraulic loss, and cools the radially outer end of the winding coil through reflux.

[0096] The flow path in the gap between the winding coils is as follows Figure 9 The dashed arrows in (b) indicate that after the cooling medium is accelerated through the cooling circulation channel inlet 5 and the liquid ejection structure 51, a low-pressure area is formed at the front impact point on both sides of the airfoil-shaped guide vanes 10. This drives the cooling liquid in the cavities on both sides to flow secondary, entering the gap area between the two adjacent winding coils 3. It then flows through the outlet drainage structure 13 to enhance cooling of the winding coil ends, and finally flows out through the cooling circulation channel outlet 6.

[0097] Figure 9 Figure (c) illustrates the overall flow path of the flow guide system. The dashed arrows indicate flow near the top of the cooling structure end cap, the dashed arrows indicate flow between the winding coils and at the ends, and the solid arrows indicate the flow of cooling liquid in and out of the flow channel inlet 5 and outlet 6.

[0098] Example 2:

[0099] like Figure 5 As shown, based on the first embodiment, this embodiment is provided with an axial flow expansion groove 12 on the outer periphery of the stator core tooth wall of the cooling structure channel, so that the inner side of the winding coil 3 has a stronger axial flow heat dissipation capability, which is used to cool the inner side of the winding coil to prevent local overheating caused by close fitting.

[0100] The above embodiments are only used to illustrate rather than limit the technical solutions of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the present invention can still be modified or replaced by equivalents. Any modification or partial replacement that does not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

[0101] If words such as "first" and "second" are used in this document to limit components, those skilled in the art should know that the use of "first" and "second" is only for the convenience of describing the present invention and simplifying the description. Unless otherwise stated, the above words have no special meaning.

[0102] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0103] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

Claims

1. An axial flux motor cooling structure, characterized by: It includes a cooling structure channel and a cooling structure end cover fixed on one axial side of the cooling structure channel, and the two are sealed and matched to form a cooling cavity; The cooling structure channel is periodically arranged along the circumferential direction with stator core mounting holes that match the shape of the stator core, and the cooling structure channel is matched with the stator core by axial plugging; The winding coil is fixed in the cooling cavity, and its lead wire passes through the side of the cooling structure channel; The bottom surface of the cooling structure channel is periodically arranged along the circumferential direction and is respectively provided with a plurality of flow channel inlets, channel guide structures and flow channel outlets; The surface of the cooling structure end cover is provided with a plurality of end cover guide structures periodically arranged along the circumferential direction; The cooling liquid flows into the sealed cooling cavity through the flow channel inlet, and under the action of the channel guide structure and the end cover guide structure, it directly contacts the winding coil to achieve heat exchange, and then flows out of the cooling cavity from the flow channel outlet; The channel guide structure includes a liquid ejection structure provided at each flow channel inlet on the bottom surface of the cooling structure channel, wherein the ejection direction of the liquid ejection structure is radially outward and the outlet cross section is a tapered Venturi structure; The channel guide structure also includes wing-shaped guide blades whose distribution positions correspond one-to-one to the liquid ejection structure, and whose axial cross-section presents a wing-shaped profile with a continuous variable curvature; the leading edge curvature radius of the wing-shaped guide blade is large and aligned with the axis of the liquid ejection structure; the middle to the tail of the wing-shaped guide blade gradually flattens, pointing to the gap between the winding coils, guiding the cooling liquid to flow into the gap between the winding coils in a directionally accelerated manner.

2. The axial flux motor cooling structure according to claim 1, characterized in that: The channel guide structure also includes a sub-cavity separation structure arranged at the axis of each winding coil and extending radially to the winding coil, which divides the sealed cooling cavity into multiple independent sub-cavities distributed on both sides of the wing-shaped guide blades, thereby blocking non-directional cross-flow between the sub-cavities.

3. The axial flux motor cooling structure according to claim 2, characterized in that: A groove is provided inside the sub-cavity partition structure for leading out the lead wires of the winding coil.

4. The axial flux motor cooling structure according to claim 2, characterized in that: The channel guide structure also includes an outlet guide structure provided at each flow channel outlet on the bottom surface of the cooling structure channel, which is composed of two arc-shaped guide surfaces arranged symmetrically along the radial axis, intersecting at the inner ends and gradually expanding toward the outer ends, and its axial cross-section presents a trumpet-shaped profile with continuous variable curvature; The inner end of the outlet drainage structure is aligned with the central axis of the gap between two adjacent winding coils, and the cooling fluid is guided to the ends of the winding coils through the arc-shaped guide surface to improve the heat exchange efficiency; the curvature direction of the arc-shaped guide surface is the same as the curvature direction of the ends of the adjacent winding coils, and the curvature of the arc-shaped guide surface is smaller than the curvature of the ends of the winding coils; The outer end opening of the outlet drainage structure is trumpet-shaped, surrounding both sides of the flow channel outlet and having a certain gap with the inner wall of the outer circle of the cooling structure channel, thereby constructing a diffusion-type Venturi structure; this diffusion-type Venturi structure can achieve a gradual slowing down of the flow velocity when the cooling fluid leaves the sealed cavity, and effectively convert part of the kinetic energy into static pressure.

5. The axial flux motor cooling structure according to any one of claims 1 to 4, characterized in that: The end cover flow guide structure includes a plurality of gap flow guide baffles, flow diversion and compression plates and an outlet return flow structure that are periodically arranged along the circumferential direction on the bottom surface of the cooling structure end cover; The gap drainage baffle is distributed between every two stator mounting holes and extends radially. Its top is pointed and can be tightly inserted between two winding coils. It can limit the flow between the gaps of two adjacent winding coils to the space between the winding coils to prevent overflow. The flow splitting and pressing plates are distributed on both sides of the gap drainage baffle, dividing the cooling fluid between the winding coil and the cooling structure end cover into multiple channels for flow, while also playing a role in pressing and fixing the winding coil; The outlet reflux structure has a curved wall reflux shape and is respectively arranged on the radial inner and outer sides of each stator mounting hole, cooperating with the cooling structure channel to form a reflux, thereby achieving enhanced cooling of the local hot spots of the winding coil.

6. The axial flux motor cooling structure according to claim 1, characterized in that: The cooling structure channel has an outer circular wall surface, an inner circular wall surface and a plurality of stator core tooth wall surfaces; sealing grooves and sealing rings are provided on the inner and outer circles of the mating surface between the cooling structure channel and the cooling structure end cover and the stator core tooth wall surface, and a sealed cooling cavity is formed by tightly fitting the fixing assembly; The winding coil is inserted into the cooling structure channel from the axial direction through the wall surface of the stator core tooth portion.

7. The axial flux motor cooling structure according to claim 6, characterized in that: An axial flow expansion groove is provided on the outer periphery of the stator core tooth wall of the cooling structure channel.

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