Stator core and aircraft generator integrated with bent multi-parallel axial microchannels

Abstract

The present invention discloses a stator core and an aircraft generator integrated with multiple parallel axial microchannels, belonging to the field of motor cooling technology. The stator core comprises an inlet section core and two flow channel section cores on either side thereof. The flow channel section core is axially divided into multiple sections, each section comprising multiple groups of axial flow channels, each group of axial flow channels comprising multiple parallel axial flow channels or comprising only one axial flow channel, with adjacent groups of flow channels converging radially to form a whole of axially parallel, radially converging zigzag flow channels. Adjacent zigzag flow channels are connected by a group of axial flow channels closest to the tooth yoke junction or closest to the tooth tip. The flow channel section core is formed by laminating silicon steel sheets in a specific form. The inlet section core is provided with an inlet flow channel connected to the zigzag flow channels in the flow channel section cores on both sides. The present invention can achieve sufficient cooling of the stator core and windings.

Description

Technical Field

[0001] The present invention belongs to the technical field of motor cooling, and more particularly, relates to a stator core and an aircraft generator integrated with bent multi-parallel axial micro-channels. Background Art

[0002] Aviation electrification and the development of more-electric aircraft have significantly simplified aircraft system architecture, reduced fuel consumption, and improved engine efficiency. With the widespread installation of large-capacity electrical equipment, the demand for onboard electrical energy in military and civilian more-electric aircraft has increased significantly. Under strict weight constraints and integrated design, generator systems, as core electrical components of aircraft, have assumed an even more crucial role in the electrification revolution. Large-capacity, even megawatt-class, high-power-density aircraft generator systems are key to the development of aviation electrification for large and medium-sized aircraft. In permanent magnet motor topologies, high-speed, high-electromagnetic load designs are often employed to increase motor power density. However, this high-speed, high-electromagnetic load design significantly increases internal heat sources such as copper and iron losses, and their distribution becomes more uneven. Furthermore, the high-temperature and low-pressure operating conditions of more-electric aircraft exacerbate heat dissipation conditions. Large-capacity, ultra-high-power-density aircraft generators face exceptionally severe thermal management challenges. Therefore, new, efficient cooling technologies for high-loss active components, such as motor windings and cores, have become a key technology in the design of megawatt-class, high-power-density aircraft generators.

[0003] At present, the base frequency of large-capacity aircraft generators can reach above 1000Hz, and the current density can reach 20A / mm 2 Above, the average copper loss density can reach 1×10 7 W / m 3 , the average iron loss density can reach 5×10 6 W / m 3 Excessive temperature rise in motors under extremely high loss density will not only cause aging of motor materials and shorten the life of the motor; in severe cases, it may even cause accidents such as short circuit and burning of the motor windings. Therefore, how to improve heat dissipation performance is the key to increasing the power density of large-capacity aircraft generators. Compared with water, oil has good insulation properties. As a cooling medium, it can directly contact the surface of the effective parts of the motor, such as the windings and the iron core, greatly reducing the thermal resistance between the heat source and the cooling medium. Therefore, oil cooling has been widely used in high-power density motors.

[0004] At present, the mainstream cooling technology used in large-capacity aircraft generators is a combination of stator casing oil circulation and winding end oil injection. However, in this cooling technology, the cooling medium generally only contacts the outer surface of the stator core and the surface of the winding end, resulting in a limited heat dissipation area. In addition, the heat dissipation path from the stator core heat source, i.e., the stator teeth, to the cooling medium is long, making it difficult to meet the heat dissipation requirements of higher power density.

[0005] The new stator oil immersion cooling technology completely immerses the heat-generating components of the motor stator core and windings in cooling oil, which can achieve a more efficient cooling effect. In the patent document with application publication number CN115459501A, a semi-sealed hybrid cooling high-speed permanent magnet motor is disclosed, such as Figure 1 As shown, it includes a stator core I1, a slot bottom flow channel I11, an inner slot flow channel I12, a stator winding I2, a support frame I3, a special-shaped stator sheath I4, a casing I5, an oil outlet hole I51, an axial flow channel I52, a heat dissipation fin I53, a driving end cover I6, an oil inlet hole I61, an annular distribution groove I62, an additional supporting cylinder wall I63, a non-driving end cover I7, a sealing ring I8, and an airtight electrical connector I9. This solution constructs a slot bottom flow channel between the bottom arc surface of the stator core and the supporting frame, and constructs an in-slot flow channel between the supporting frame, the stator winding and the stator heterogeneous sheath. Combined with liquid cooling and natural cooling of the casing, the overall cooling structure has the advantages of compact structure and high reliability. However, the slot bottom flow channel and the in-slot flow channel have a good cooling effect on the motor winding, but are far away from the heat source of the motor stator core teeth. The thermal resistance on the heat transfer path is large, and the stator teeth cannot be efficiently cooled. At the same time, the support structure between the stator yoke and the winding occupies additional slot area, which is not conducive to the improvement of power density.

[0006] In the patent document with application publication number CN111555486A, a motor stator cooling structure and a motor are disclosed, such as Figure 2 As shown, it includes a stator core II2, a first cover plate II31; a first plug-in platform II311, a second cover plate II41, a second plug-in platform II411, and a baffle II5. This solution has two covers at both axial ends of the stator core, and multiple slots and baffles arranged circumferentially. The first cover, the second cover, the baffles, and the multiple slots form a cooling channel extending circumferentially along the stator core, isolating the coolant from the motor rotor. This solves the problem of motor energy loss caused by the rotation of the motor rotor stirring the coolant, and improves the power density of the motor. However, the structure is relatively complex, and while the cooling system has a good cooling effect on the winding ends and the stator core yoke, the temperature of the windings in the slots and the core teeth is relatively high.

[0007] In general, existing oil immersion cooling usually sets axial flow channels at the stator slots and yokes. The temperature difference between the oil channel inlet and outlet is large, the axial heat dissipation effect of the motor is uneven, and the distance between the heat source and the cooling medium is still far. The heat dissipation performance still cannot meet the heat dissipation requirements of extremely high loss density. Summary of the Invention

[0008] In response to the defects and improvement needs of the existing technology, the present invention provides a stator core and an aircraft generator integrated with bent multi-parallel axial microchannels, the purpose of which is to achieve sufficient cooling of the stator core and windings.

[0009] According to one aspect of the present invention, there is provided a stator core integrated with bent-type multiple parallel axial micro-channels, comprising: an inlet section core and channel section cores on both sides thereof;

[0010] Along the axial middle portion to the axial end portion of the stator core, the flow channel section core sequentially includes a shunt core segment, a plurality of parallel core segments, and an outlet core segment; a first converging unit or a second converging unit is provided between every two adjacent parallel core segments, and the first converging units and the second converging units are alternately arranged along the axial direction;

[0011] Each stator tooth of the parallel core segment is provided with radially arranged K A set of axial flow channels, each set of axial flow channels consists of N The axial flow channels are connected in parallel; N is a positive integer, K is an odd number, and N ≥ 2, K ≥3;

[0012] In the shunt core section, each stator tooth is provided with a radial shunt channel and The first converging flow channel is connected to the adjacent parallel core segments; the diverging flow channel is connected to a group of axial flow channels closest to the yoke, and each first converging flow channel is connected to two adjacent groups of axial flow channels in the adjacent parallel core segments;

[0013] In the lead-out core section, each stator tooth is provided with a radial lead-out channel and The outlet flow channel is connected to a group of axial flow channels closest to the tooth tip in the adjacent parallel core segment, and each second converging flow channel is connected to two adjacent groups of axial flow channels in the adjacent parallel core segment;

[0014] The first convergence unit includes two first convergence core segments and a yoke flow channel core segment arranged between the two first convergence core segments; in the first convergence core segment, each stator tooth is provided with N The first yoke flow channel and radial flow channels, N The first yoke flow passages are respectively connected to the adjacent parallel core segments closest to the tooth yoke junction. N The axial flow channels are matched, and each radial flow channel is connected to the two adjacent axial flow channels in the adjacent parallel core segments; each stator tooth in the yoke flow channel opening core segment is provided with a N The first yoke flow passages are respectively matched with N a second yoke flow passage;

[0015] The second convergence unit includes two second convergence core segments and a tooth tip flow channel core segment arranged between the two second convergence core segments; in the second convergence core segment, each stator tooth is provided with N The first tooth tip flow channel and radial flow channels, N The first tooth tip flow channel openings are respectively connected to the adjacent parallel core segments closest to the tooth tip. N The axial flow channels are matched, and each radial flow channel is connected to the two adjacent axial flow channels in the adjacent parallel core segments; each stator tooth in the tooth tip flow channel opening core segment is provided with a N The first tooth tip flow channel openings are respectively matched N A second tooth tip flow channel;

[0016] An inlet flow channel corresponding to each tooth portion is provided on the inlet section core. One end of the inlet flow channel is used to inject cooling medium, and the other end is matched with the shunt flow channel on the shunt core section.

[0017] Furthermore, the inlet flow channel on the inlet section core is a stepped flow channel.

[0018] Further, the entrance section core comprises: an entrance core section, the outer edge of which is circumferentially provided with grooves corresponding to the teeth;

[0019] Each side of the entrance core segment is provided with M The secondary drainage core segment; each side of the inlet core segment M In the drainage core segments, the yoke of each drainage core segment is provided with drainage holes corresponding to the teeth along the circumference. The drainage holes on the drainage core segments closer to the corresponding side flow channel segment are closer to the junction of the teeth and yoke.

[0020] The drainage holes on the first-stage drainage core segment partially overlap with the corresponding grooves on the inlet core segment; the corresponding drainage holes on the two adjacent drainage core segments partially overlap; the drainage holes on the last-stage drainage core segment match with the diversion channels on the diversion core segment;

[0021] in, M Is a positive integer.

[0022] Furthermore, the end of the groove on the outer edge of the inlet core segment is an arc; the first and last ends of each level of the drainage core segment are arcs; the first and last ends are the radially outermost and innermost ends respectively;

[0023] The arc at the end of the groove on the outer edge of the inlet core segment coincides with the center of the arc at the beginning of the hole of the yoke of the adjacent drainage core segment and the apertures are equal; in two adjacent drainage core segments, the arc at the end of the hole of the yoke of the previous drainage core segment coincides with the center of the arc at the beginning of the hole of the yoke of the next drainage core segment and the apertures are equal.

[0024] Furthermore, the width of the radial converging channel d 1 and the width of the axial flow channel in the parallel core segment d 2 Satisfaction: d 1= N ×d 2;

[0025] The radial converging flow channels include the radial flow channels in the first converging core segment, the radial flow channels in the second core segment, the first converging channel in the diverting core segment, and the second converging channel in the leading core segment.

[0026] The width of the radial flow channel in the first converging core segment and the second core segment d 1 and the width of the axial flow channel in the parallel core segment d 2 Satisfaction: d 1= N × d 2.

[0027] According to another aspect of the present invention, there is provided a stator core integrated with a bent axial micro-channel, comprising: an inlet section core and flow channel section cores on both sides thereof;

[0028] Along the axial middle portion to the axial end portion of the stator core, the runner section core sequentially includes a first converging core segment, a plurality of parallel core segments, and a second converging core segment. A first converging unit or a second converging unit is provided between every two adjacent parallel core segments, and the first converging units and the second converging units are alternately arranged along the axial direction.

[0029] Each stator tooth of the parallel core segment is provided with radially arranged K Axial flow channel; K is an odd number, and K ≥3;

[0030] The first convergence unit includes two first convergence core segments and a yoke flow channel core segment arranged between the two first convergence core segments; in the first convergence core segment, each stator tooth is provided with a first yoke flow channel and The first yoke runner opening matches the axial runner in the adjacent parallel core segment closest to the tooth yoke junction, and each radial runner is connected to two adjacent axial runners in the adjacent parallel core segment; a second yoke runner opening matching the first yoke runner opening is provided on each stator tooth in the core segment of the yoke runner opening;

[0031] The second convergence unit includes two second convergence core segments and a tooth tip flow channel core segment disposed between the two second convergence core segments; in the second convergence core segment, each stator tooth is provided with a first tooth tip flow channel and a radial flow channels, the first tooth tip flow channel opening matches the axial flow channel closest to the tooth tip in the adjacent parallel core segment, and each radial flow channel is connected to two adjacent axial flow channels in the adjacent parallel core segment; a second tooth tip flow channel opening matching the first tooth tip flow channel opening is provided on each stator tooth in the core segment with the tooth tip flow channel opening;

[0032] An inlet flow channel corresponding to each tooth portion is provided on the inlet section core. One end of the inlet flow channel is used to inject cooling medium, and the other end is matched with the first yoke flow channel opening on the adjacent first converging core segment.

[0033] Furthermore, the inlet flow channel on the inlet section core is a stepped flow channel.

[0034] Further, the entrance section core comprises: an entrance core section, the outer edge of which is circumferentially provided with grooves corresponding to the teeth;

[0035] Each side of the entrance core segment is provided with M The secondary drainage core segment; each side of the inlet core segment M In the drainage core segments, the yoke of each drainage core segment is provided with drainage holes corresponding to the teeth along the circumference. The drainage holes on the drainage core segments closer to the corresponding side flow channel segment are closer to the junction of the teeth and yoke.

[0036] The drainage holes on the first-stage drainage core segment partially overlap with the corresponding grooves on the inlet core segment; the corresponding drainage holes on the two adjacent drainage core segments partially overlap; the drainage holes on the last-stage drainage core segment match with the first yoke flow channel opening on the adjacent first converging core segment;

[0037] in, M Is a positive integer.

[0038] Furthermore, the end of the groove on the outer edge of the inlet core segment is an arc; the first and last ends of each level of the drainage core segment are arcs; the first and last ends are the radially outermost and innermost ends respectively;

[0039] The arc at the end of the groove on the outer edge of the inlet core segment coincides with the center of the arc at the beginning of the hole of the yoke of the adjacent drainage core segment and the apertures are equal; in two adjacent drainage core segments, the arc at the end of the hole of the yoke of the previous drainage core segment coincides with the center of the arc at the beginning of the hole of the yoke of the next drainage core segment and the apertures are equal.

[0040] According to another aspect of the present invention, an aircraft generator is provided, comprising any one of the above-mentioned stator cores integrated with bent-type multi-parallel axial micro-channels provided by the present invention.

[0041] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

[0042] (1) The stator core provided by the present invention is integrated with bent multi-parallel axial micro-channels. The cooling medium is injected from the middle and flows out from both ends, thereby effectively solving the problem of uneven axial heat dissipation of the motor. When the motor shaft is long, its advantage is more obvious. Inside each flow channel section core, there are multiple parallel core sections. The stator teeth of the parallel core sections are provided with multiple groups of parallel axial flow channels (each group of axial flow channels specifically includes one axial flow channel or multiple parallel axial flow channels). Each parallel core section is connected to the corresponding converging core section on both sides. The two adjacent groups of flow channels are converged together through the radial flow channels on the converging core segment. The axial flow channels cooperate with the radial flow channels to form a curved "snake-shaped" cooling channel with axial parallel connection and radial convergence, which increases the contact area between the cooling medium and the heat source of the stator core, and reduces the distance between the winding heat source and the cooling medium. In addition, the turbulence of the cooling medium flow is enhanced, the thermal boundary layer of the microchannel wall is effectively destroyed, and the convection heat transfer coefficient is significantly increased, thereby achieving full cooling of the stator core and winding.

[0043] (2) In the stator core provided by the present invention, which is integrated with bent multi-parallel axial microchannels, in its preferred embodiment, the inlet flow channel in the inlet section of the core is set to be stepped, which can reduce the influence of each section of the inlet flow channel on the magnetic circuit of the stator core yoke, and avoid the influence of the electromagnetic performance of the inlet section of the core due to the interruption of the yoke magnetic circuit.

[0044] (3) In the stator core provided by the present invention, which is integrated with multiple parallel bent microchannels, the width of the radial channel is d 1 is the width of the axial flow channel in the parallel core segment d 2 of N times ( N is the number of parallel branches of each group of axial flow channels), thereby ensuring that the flow velocity of the cooling medium in the axial flow channels is not affected after it converges in the radial direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a schematic diagram of an existing semi-sealed hybrid cooling high-speed permanent magnet motor;

[0046] Figure 2 The figure is a schematic diagram of an existing motor stator cooling structure and a motor;

[0047] Figure 3 This is an overall schematic diagram of a stator core integrated with bent multi-parallel axial microchannels provided in Example 1 of the present invention;

[0048] Figure 4 A diagram showing the assembly of the inlet section core provided in Example 1 of the present invention;

[0049] Figure 5Schematic diagram of the structure of various core segments in the inlet core provided in Example 1 of the present invention; wherein (a) is the inlet core segment, (b) is the first-stage drainage core segment, and (c) is the second-stage drainage core segment;

[0050] Figure 6 A schematic diagram of the flow of the cooling medium in the iron core of the inlet section provided by Example 1 of the present invention;

[0051] Figure 7 Schematic diagram of the structures of various core segments in the flow channel segment core provided in Example 1 of the present invention; wherein (a) is a shunt core segment, (b) is a parallel core segment, (c) is a lead core segment, (d) is a first converging core segment, (e) is a yoke flow channel opening core segment, (f) is a second converging core segment, and (g) is a tooth tip flow channel opening core segment;

[0052] Figure 8 A schematic diagram of stacking the drain core segments provided in Example 1 of the present invention;

[0053] Figure 9 Schematic diagram of the integral stacking of the core segments in the runner segment core provided in Example 1 of the present invention;

[0054] Figure 10 Schematic diagram of microchannel core assembly and cooling medium flow provided in Example 1 of the present invention;

[0055] Figure 11 This is a schematic diagram of the assembly of the single-side runner section core provided in Example 1 of the present invention;

[0056] Figure 12 A schematic diagram of the overall structure of the stator core and the cooling medium flow path provided in Example 1 of the present invention;

[0057] Figure 13 Schematic diagram of another core segment in a flow channel segment provided by the present invention; wherein (a) is a shunt core segment, (b) is a parallel core segment, (c) is a lead core segment, (d) is a first converging core segment, and (e) is a second converging core segment;

[0058] Figure 14 This is an overall schematic diagram of the runner section core provided in Example 2 of the present invention;

[0059] Figure 15 Schematic diagram of various core segments in the runner segment core provided in Example 2 of the present invention; wherein (a) is a parallel core segment, (b) is a first converging core segment, (c) is a yoke runner opening core segment, (d) is a second converging core segment, and (e) is a tooth tip runner opening core segment;

[0060] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0061] I1 - stator core; I11 - slot bottom flow channel, I12 - slot inner flow channel; I2 - stator winding; I3 - support frame; I4 - special-shaped stator jacket; I5 - housing; I51 - oil outlet, I52 - axial flow channel, I53 - cooling fins; I6 - drive end cover; I61 - oil inlet, I62 - annular distribution groove, I63 - additional support cylinder wall; I7 - non-drive end cover; I8 - sealing ring; I9 - airtight electrical connector;

[0062] II2-stator core; II31-first cover plate; II311-first plug-in platform, II41-second cover plate; II411-second plug-in platform; II5-blocking piece;

[0063] 11-entrance core; 111-entrance core segment, 112-first stage drainage core segment, 113-second stage drainage core segment;

[0064] 12- flow channel section core; 121- shunt core section, 122- parallel core section, 123- lead core section, 124- first convergent core section, 125- yoke flow channel opening core section, 126- second convergent core section, 127- tooth tip flow channel opening core section;

[0065] 22- flow channel section core; 221- parallel core section, 222- first convergent core section, 223- yoke flow channel opening core section, 224- second convergent core section, 225- tooth tip flow channel opening core section. DETAILED DESCRIPTION

[0066] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0067] In the present invention, the terms "first", "second", etc. (if any) in the present invention and the drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0068] In order to effectively solve the problem of heat dissipation difficulties in the core and winding of large-capacity, ultra-high power density aviation motors with extremely high loss density, the present invention proposes a stator core integrated with bent multi-parallel axial micro-channels. To address the problem of uneven axial heat dissipation of the motor, the stator cooling system is designed so that the cooling medium enters the stator core from the middle and flows out to both ends; the stator core is divided into three sections along the axial direction, including an inlet section core located in the middle and a flow section core with axial radial micro-channels of the stator tooth yoke located on both sides of the inlet section core, such as Figure 3As shown, this design can construct a new internal cooling structure of the axial and radial micro-channels of the stator core tooth yoke based on traditional silicon steel sheet processing methods or 3D printing technology, integrating the radiator with the motor stator core to achieve sufficient cooling of the stator core and windings. This stator core micro-channel internal cooling structure is suitable for both oil spray cooling or oil immersion cooling of aviation fuel and aviation lubricating oil, and is also suitable for internal cooling of other insulating cooling media, such as air, helium, hydrogen, etc. After the cooling medium enters the middle of the stator core, it flows axially toward both ends of the core. N The axial flow channels connected in parallel flow in the parallel core segments along the axial direction. K Second, radially inward and radially outward flow occurs in the converging core segment. N Represents the number of parallel branches, which is a positive integer greater than or equal to 2; K is an odd number greater than or equal to 3.

[0069] This cooling architecture significantly reduces the heat source heat dissipation path, significantly increases the heat dissipation area and heat transfer coefficient, and makes the microchannel internal cooling have a very strong cooling effect.

[0070] This invention integrates electromagnetic energy conversion with a microchannel heat sink within the stator core. To minimize the impact of the microchannel design on electromagnetic performance while maximizing heat dissipation, the core's internal flow channel design adheres to three principles: minimizing interruption of the motor's magnetic circuit, positioning the microchannel close to the heat source, and maximizing the heat dissipation area.

[0071] Based on the above concepts and design principles, in one embodiment of the present invention, namely, embodiment 1, a stator core is provided which is integrated with bent multi-parallel axial micro-channels. Figures 3 to 12 The structure shown includes: an inlet section core 11 and flow channel section cores 12 on both sides thereof.

[0072] The flow channel section core 12 is provided with axially parallel, radially converging curved cooling channels, and the inlet section core 11 is provided with inlet channels that match the cooling channels in the flow channel section cores on both sides. During cooling, the cooling medium first enters the stator core through the inlet section core in the middle of the stator core. In order to reduce the influence of the channels on the magnetic circuit of the core yoke, in this embodiment, the inlet channels in the inlet section core connected to the flow channel section cores on each side are set in a two-step shape, such as Figure 6 and Figure 12 As shown, in order to facilitate the formation of the two-step ladder, in this embodiment, the entrance section core is designed to Figure 4 The structure shown is composed of multiple core segments combined along the axial direction, and the entrance core 11 specifically includes: an entrance core segment 111, and each side of the entrance core segment is respectively provided with two-stage drainage core segments; the entrance core segment 111, the first-stage drainage core segment 112 and the second-stage drainage core segment 113 are respectively as shown in FIG. Figure 5As shown in (a), (b) and (c) in Figure 5 As shown in (a), the outer edge of the entrance core segment 111 is provided with grooves corresponding to the teeth on a circumferential basis; Figure 5 As shown in (b) and (c) in the figure, in the two-stage drainage core segments on each side, the yoke of each stage of the drainage core segment is provided with drainage holes corresponding to the teeth along the circumference, and the drainage holes on the drainage core segment closer to the corresponding side flow channel segment are closer to the junction of the teeth and yoke; the drainage holes on the first stage of the drainage core segment 112 partially overlap with the corresponding grooves on the inlet core segment 111, and the corresponding drainage holes on the adjacent two stages of the drainage core segment partially overlap, thereby forming a Figure 6 and Figure 12 The two-stage stepped inlet flow channel shown; the drainage hole of the last-stage drainage core segment matches the corresponding diversion flow channel on the adjacent diversion core segment, thereby introducing the cooling medium flow channel into the flow channel segment core.

[0073] In the inlet section core designed in this way, the magnetic circuit of each stator core section cross section is not interrupted, so each stator core section has little effect on the electromagnetic performance of the motor.

[0074] In order to make the inner wall of the flow channel in each level of the core segment fit tightly, in this embodiment, the radially outermost end is the head end, the radially innermost end is the tail end, and the end of the groove on the outer edge of the inlet core segment is an arc; the head and tail ends of each level of the drainage core segment are both arcs; the arc at the end of the groove on the outer edge of the inlet core segment coincides with the center of the arc at the head end of the hole of the adjacent drainage core segment yoke and the aperture is equal; in two adjacent drainage core segments, the arc at the end of the hole of the yoke of the previous drainage core segment coincides with the center of the arc at the head end of the hole of the yoke of the next drainage core segment and the aperture is equal. The inlet flow channel formed after the core segments are assembled, and the flow path of the cooling medium in the inlet core after entering the core are shown as follows. Figure 6 shown.

[0075] It should be noted that the number of stages of the stepped inlet flow channel can be designed according to the actual axial length, yoke thickness and cooling requirements of the motor. In some other embodiments of the present invention, it can also be set to other numbers besides 2.

[0076] After the cooling medium enters the stator core through the inlet section core, the heat source of the motor stator is cooled mainly through the flow channel section cores on both sides. In order to shorten the distance between the heat source and the cooling medium and increase the contact area between the heat source and the cooling medium, this embodiment forms an axial microchannel in the stator core heat source, i.e., the stator tooth yoke, by processing part of the core laminations, which plays the main role in heat dissipation. In order to minimize the impact on electromagnetic performance, the width of the tooth microchannel is comprehensively designed, and the extended length of the yoke does not affect the magnetic circuit of the motor. This design method for constructing microchannels inside the stator core can be combined with additive manufacturing technology to construct a microchannel structure scheme for the tooth yoke in three-dimensional space based on the construction principle.

[0077] In this embodiment, the number of parallel branches of the axial flow channel in the parallel core segment is N =2, and the number of times the two parallel axial flow channels flow in the parallel section core is K =3, such as Figure 10 shown.

[0078] Since the embedded integrated design of micro-channels makes the structure of the core more complicated, this embodiment takes into account the actual industrial processing, based on the limitations of silicon steel sheet processing technology and the characteristics of core processing, and takes the principle of minimizing the number of silicon steel sheets, a total of seven different stator tooth yoke silicon steel sheets are designed for the radial micro-channel heat sink part of the stator core axis. Figure 7 As shown; Figure 7 (a) shows the silicon steel sheet of the shunt core segment, each stator tooth of which is provided with a radial shunt flow channel and a first converging flow channel; Figure 7 (b) shows the parallel core segment silicon steel sheets, each of which has six radially arranged drainage holes on each stator tooth. After the silicon steel sheets are stacked, three groups of axial flow channels are formed, and each group of axial flow channels is composed of two axial flow channels connected in parallel; Figure 7 (c) shows the silicon steel sheets of the lead-out core segment, and each stator tooth is provided with a radial lead-out flow channel and a second converging flow channel; Figure 7 (d) shows the silicon steel sheets of the first converging core segment, each of which is provided with two first yoke flow channel openings and one radial flow channel; Figure 7 (e) shows the yoke runner opening of the core segment silicon steel sheet, and each stator tooth is provided with two first yoke runner openings; Figure 7 (f) shows the silicon steel sheets of the second converging core segment, each of which is provided with two first tooth tip flow passages and one radial flow passage; Figure 7 (g) shows the silicon steel sheet of the core segment of the tooth tip flow channel, and each stator tooth is provided with two second tooth tip flow channel openings.

[0079] In this embodiment, in order to minimize process costs and enhance industrialization potential, seven types of silicon steel sheets are stacked separately to form corresponding core segments, that is, multiple shunt core segment silicon steel sheets are stacked to form a shunt core segment, multiple parallel core segment silicon steel sheets are stacked to form a parallel core segment, multiple lead-out core segment silicon steel sheets are stacked to form a lead-out core segment, multiple first convergent core segment silicon steel sheets are stacked to form a first convergent core segment, multiple yoke flow channel opening core segment silicon steel sheets are stacked to form a yoke flow channel opening core segment, multiple second convergent core segment silicon steel sheets are stacked to form a second convergent core segment, and multiple tooth tip flow channel opening silicon steel sheets are stacked to form a tooth tip flow channel opening core segment. Figure 8 The figure shows a schematic diagram of a drainage core segment formed by laminating multiple 0.5mm silicon steel sheets.

[0080] like Figure 9 、 Figure 10 and Figure 11 As shown, based on the above-mentioned seven types of silicon steel sheets, in this embodiment, the runner segment core 12 specifically includes: a shunt core segment 121, a plurality of parallel core segments 122, and a lead core segment 123, which are sequentially arranged along the axial middle portion to the axial end portion of the stator core; a first converging unit or a second converging unit is provided between every two adjacent parallel core segments 122, and the first converging units and the second converging units are alternately arranged along the axial direction;

[0081] Each stator tooth of the parallel core segment 122 is provided with three groups of radially arranged axial flow channels, and each group of axial flow channels is formed by two axial flow channels connected in parallel;

[0082] In the split core segment 121, each stator tooth is provided with a radial split flow channel and a first converging flow channel; the split flow channel is connected to a group of axial flow channels closest to the yoke in the adjacent parallel core segment 122, and each first converging flow channel is connected to two adjacent groups of axial flow channels in the adjacent parallel core segment 122;

[0083] In the lead-out core segment 123, each stator tooth is provided with a radial lead-out flow channel and a second converging flow channel; the lead-out flow channel is connected to a group of axial flow channels closest to the tooth tip in the adjacent parallel core segment, and each second converging flow channel is connected to two adjacent groups of axial flow channels in the adjacent parallel core segment;

[0084] The first converging unit includes two first converging core segments 124 and a yoke flow channel core segment 125 disposed between the two first converging core segments 124; in the first converging core segment 124, each stator tooth is provided with two first yoke flow channel openings and one radial flow channel, the two first yoke flow channel openings respectively matching the two axial flow channels closest to the tooth-yoke junction in the adjacent parallel core segments 122, and each radial flow channel is connected to two adjacent groups of axial flow channels in the adjacent parallel core segments 122; each stator tooth in the yoke flow channel core segment 125 is provided with two second yoke flow channel openings respectively matching the two first yoke flow channel openings;

[0085] The second converging unit includes two second converging core segments 126 and a tooth tip flow channel opening core segment 127 arranged between the two second converging core segments 126; in the second converging core segment 126, each stator tooth is provided with two first tooth tip flow channel openings and one radial flow channel, and the two first tooth tip flow channel openings are respectively matched with the two axial flow channels closest to the tooth tip in the adjacent parallel core segments 122, and each radial flow channel is connected to the two adjacent groups of axial flow channels in the adjacent parallel core segments 122; each stator tooth in the tooth tip flow channel opening core segment 127 is provided with two second tooth tip flow channel openings respectively matched with the two first tooth tip flow channel openings.

[0086] like Figure 10 and Figure 12 As shown, after the cooling medium flows into the flow channel section core through the inlet section core, it is diverted through the diverter flow channel on the diverter core section to the two axial flow channels in the parallel core section closest to the tooth yoke junction; after flowing to the radial flow channel in the second converging core section, it converges radially and flows radially inward, and then diverts to the next group of axial flow channels, and after flowing to the first converging flow channel in the diverter core section, it converges radially and flows radially inward, and then diverts to a group of axial flow channels closest to the tooth tip, and flows axially to the next parallel unit; similarly, in the next parallel unit, the cooling medium will flow axially, and after flowing to the radial flow channel in the first converging core section, it converges radially and flows radially outward, and then diverts to the next group of axial flow channels, and after flowing to the radial flow channel in the second converging core section, it converges radially and flows radially inward, and then diverts to a group of axial flow channels closest to the tooth yoke junction, and flows axially to the next parallel unit. And so on, until it flows to the axial end, converges in the radial direction through the lead-out flow channel on the lead-out core segment, and then flows out of the core.

[0087] It can be seen that the interior of the core of the flow channel section is an axially parallel and radially converging curved flow channel. The cooling medium flows axially as a whole in the curved flow channel, while performing reciprocating axial motion along the core teeth. At the same time, it flows radially inward and radially outward along the stator core teeth in the radial direction. The contact area between the cooling medium and the heat source in the microchannel is effectively improved, and the distance between the heat source and the cooling medium is effectively shortened. The turbulence of the cooling medium flow is enhanced, the thermal boundary layer of the microchannel wall is effectively destroyed, and the convective heat transfer coefficient is significantly increased.

[0088] It should be noted that in order to clearly show the flow path form inside the core, Figure 12 The axial flow channel is only schematically shown, and each parallel flow channel is not specifically shown.

[0089] In this embodiment, a special shunt core segment is provided on the flow channel segment core, which enables the cooling medium to evenly enter the flow channel in the flow channel segment core. At the same time, a special lead-out core segment is provided on the flow channel segment core, which enables the cooling medium to quickly and smoothly flow out of the stator core.

[0090] In addition, in order to ensure that the flow of the cooling medium is not affected when it converges in the radial direction, in this embodiment, the width of the converging flow channel in each radial direction is set to d 1. Width of axial flow channel d 2 Satisfaction: d 1= N × d 2. The radial converging flow channels include the radial flow channels in the first converging core segment, the radial flow channels in the second core segment, the first converging channel in the diverting core segment, and the second converging channel in the leading core segment.

[0091] It should be noted that in actual application, the axial length of each stator core segment is designed according to the axial length of the motor stator and the cooling requirements; the number of parallel axial flow channels is N And the number of reciprocating flows of each set of axial flow channels in the parallel core segments K It can also be set to other values ​​as needed; for example, for a stator core with a larger radial dimension, when the number of radial parallel connections remains unchanged, each set of axial flow channels can reciprocate more times in the parallel unit, for example, 5 times. In this case, the parallel core segment contains a total of 2×5=10 axial flow channels, and the numbers of radial flow channels in the split core segment, the lead-out core segment, the first converging core segment, and the second converging core segment are respectively The specific structures of the shunt core segment, the parallel core segment, the lead-out core segment, the first convergent core segment and the second convergent core segment are as follows: Figure 13As shown in (a), (b), (c), (d), and (e) in the figure, when the number of reciprocating flows in the axial flow channel remains unchanged and the number of parallel branches increases, the number of flow openings in the core segment where the flow openings are set can be increased accordingly.

[0092] In summary, the stator core teeth proposed in this embodiment increase the contact area between the cooling medium and the stator core heat source, shorten the distance to the stator core and winding heat sources, and effectively reduce the internal temperature of the core and windings. This provides extremely high cooling efficiency. This temperature reduction allows the motor to withstand higher electromagnetic loads, further improving the motor's power density. The overall stator cooling structure is achieved by axially arranging and stacking different types of stator core segments. Each stator core segment complies with the characteristics of silicon steel sheet processing technology, showing potential for industrial application and promotion.

[0093] Based on the same concept and design principle, in another embodiment of the present invention, namely, embodiment 2, another stator core integrated with bent axial microchannels is provided, such as Figure 14 and Figure 15 As shown, this embodiment is similar to the above embodiment 1, except that, in this embodiment, each group of axial flow channels only includes one axial flow channel, namely N =1. At this point, when the cooling medium flows into the flow channel segment core, there is no need for diversion, and the first converging core segment can be used directly. Furthermore, when the cooling medium flows out of the flow channel segment core, there is no need for convergence, and the second converging core segment can be used directly. Accordingly, the stator core with integrated bent multi-parallel axial microchannels provided in this embodiment includes: an inlet segment core and flow channel segment cores 22 on both sides thereof;

[0094] From the axial middle portion to the axial end portion of the stator core, the flow channel core 22 includes a first converging core segment 222, a plurality of parallel core segments 221, and a second converging core segment 224. A first converging unit or a second converging unit is provided between every two adjacent parallel core segments 221, and the first converging units and the second converging units are alternately arranged along the axial direction.

[0095] Each stator tooth of the parallel core segment 221 is provided with three radially arranged axial flow channels;

[0096] The first converging unit includes two first converging core segments 222 and a yoke flow channel opening core segment 223 disposed between the two first converging core segments 222; in the first converging core segment 222, each stator tooth is provided with a first yoke flow channel opening and a radial flow channel, the first yoke flow channel opening being matched with the axial flow channel closest to the tooth-yoke junction in the adjacent parallel core segment 221, and each radial flow channel is connected to two adjacent axial flow channels in the adjacent parallel core segment 221; each stator tooth in the yoke flow channel opening core segment 223 is provided with a second yoke flow channel opening matched with the first yoke flow channel opening;

[0097] The second converging unit includes two second converging core segments 224 and a tooth tip flow channel opening core segment 225 disposed between the two second converging core segments 224; in the second converging core segment 224, each stator tooth is provided with a first tooth tip flow channel opening and a radial flow channel, the first tooth tip flow channel opening being aligned with the axial flow channel closest to the tooth tip in the adjacent parallel core segment 221, and each radial flow channel being connected to two adjacent axial flow channels in the adjacent parallel core segment 221; each stator tooth in the tooth tip flow channel opening core segment is provided with a second tooth tip flow channel opening aligned with the first tooth tip flow channel opening;

[0098] An inlet flow channel corresponding to each tooth portion is provided on the inlet section core. One end of the inlet flow channel is used to inject cooling medium, and the other end is matched with the first yoke flow channel opening on the adjacent first converging core segment.

[0099] In order to avoid affecting the magnetic circuit, in this embodiment, the inlet flow channel in the inlet section core also adopts a stepped design. For details, please refer to the description of the above embodiment 1.

[0100] In this embodiment, the runner section core is also formed by stacking corresponding silicon steel sheets. The specific structures of the parallel core section, the first convergent core section, the yoke runner opening core section, the second convergent core section and the tooth tip runner opening core section are as follows: Figure 15 As shown in (a), (b), (c), (d) and (e).

[0101] Similarly, in practical applications, the axial length of each stator core segment and the number of reciprocating flows of the axial flow channel in the parallel core segments can be designed according to the axial length of the motor stator and the cooling requirements. K .

[0102] Based on the designed stator core integrated with bent multi-parallel axial microchannels, in another embodiment of this embodiment, namely embodiment 3, an aircraft generator is provided, which includes the stator core integrated with bent multi-parallel axial microchannels provided in the above embodiment 1, or the stator core integrated with bent axial microchannels provided in the above embodiment 2.

[0103] The active components of a high-power-density permanent magnet aircraft generator primarily consist of a stator core, windings, a rotor core, and magnets. Because high-speed rotor rotation causes significant frictional losses, the present invention utilizes a novel cooling design exclusively for the stator assembly. In the stator assembly design based on the present invention, the motor housing fits tightly against the outer surface of the stator core, with an oil separator positioned in the air gap. The oil separator adheres closely to the stator teeth, and seals are formed between the ends of the stator oil separator and the front and rear end covers of the motor to prevent leakage of the cooling medium into the rotor assembly. In other words, the stator side of the aircraft generator designed using the present invention forms a closed structure that completely encloses the stator core and windings through the housing, front and rear end covers, and stator oil separator. In the present invention, an oil inlet is provided in the axial middle portion of the casing, and a groove on the outer edge of the stator inlet core segment forms an annular cooling medium inlet channel between the casing and the stator core. After the cooling medium enters the motor casing through the oil inlet, it flows circumferentially along the groove on the outer edge of the stator inlet core segment and evenly enters the drainage holes corresponding to each stator tooth. The cooling medium flows radially along the axis of the micro-channel structure inside the stator core toward the two ends of the core, cooling the stator core and the windings in the slots, and flows out through the tooth tip flow channel outlets at both ends of the stator core to cool the winding ends.

[0104] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A stator core integrated with bent multi-parallel axial microchannels, characterized in that: include: The inlet section core and the runner section cores on both sides; Along the axial middle portion to the axial end portion of the stator core, the flow channel section core sequentially includes a shunt core segment, a plurality of parallel core segments, and an outlet core segment; a first converging unit or a second converging unit is provided between every two adjacent parallel core segments, and the first converging units and the second converging units are alternately arranged along the axial direction; Each stator tooth of the parallel core segment is provided with radially arranged K A set of axial flow channels, each set of axial flow channels consists of N The axial flow channels are connected in parallel; N is a positive integer, K is an odd number, and N ≥ 2, K ≥3; In the shunt core segment, each stator tooth is provided with a radial shunt flow channel and The first converging flow channel is connected to the adjacent parallel core segments, and the diverging flow channel is connected to the group of axial flow channels closest to the yoke. Each first converging flow channel is connected to two adjacent groups of axial flow channels in the adjacent parallel core segments. In the lead-out core segment, each stator tooth is provided with a radial lead-out flow channel and The outlet flow channel is connected to a group of axial flow channels closest to the tooth tip in the adjacent parallel core segments, and each second converging flow channel is connected to two adjacent groups of axial flow channels in the adjacent parallel core segments; The first convergence unit includes two first convergence core segments and a yoke runner core segment disposed between the two first convergence core segments; in the first convergence core segment, each stator tooth is provided with N The first yoke flow channel and radial flow channels, N The first yoke flow passages are respectively connected to the adjacent parallel core segments closest to the tooth yoke junction. N The axial flow channels are matched, and each radial flow channel is connected to two adjacent sets of axial flow channels in the adjacent parallel core segments; each stator tooth in the yoke flow channel opening core segment is provided with a N The first yoke flow passages are respectively matched with N a second yoke flow passage; The second convergence unit includes two second convergence core segments and a tooth tip flow channel opening core segment disposed between the two second convergence core segments; in the second convergence core segment, each stator tooth is provided with N The first tooth tip flow channel and radial flow channels, N The first tooth tip flow channel openings are respectively connected to the adjacent parallel core segments closest to the tooth tip. N The axial flow channels are matched, and each radial flow channel is connected to two adjacent sets of axial flow channels in the adjacent parallel core segments; each stator tooth in the tooth tip flow channel opening core segment is provided with a N The first tooth tip flow channel openings are respectively matched N A second tooth tip flow channel; The inlet section iron core is provided with an inlet flow channel corresponding to each tooth portion one by one. One end of the inlet flow channel is used for injecting cooling medium, and the other end is matched with the shunt flow channel on the shunt core section.

2. The stator core integrated with bent multi-parallel axial micro-channels according to claim 1, characterized in that: The inlet flow channel on the inlet section iron core is a stepped flow channel.

3. The stator core integrated with bent multi-parallel axial micro-channels according to claim 2, characterized in that: The entrance section core comprises: an entrance core section, the outer edge of which is circumferentially provided with grooves corresponding to the teeth; Each side of the inlet core segment is provided with M The inlet core segment on each side M In the drainage core segments, the yoke of each drainage core segment is provided with drainage holes corresponding to the teeth along the circumference. The drainage holes on the drainage core segments closer to the corresponding side flow channel segment are closer to the junction of the teeth and yoke. The drainage holes on the first-stage drainage core segment partially overlap with the corresponding grooves on the inlet core segment; the corresponding drainage holes on the two adjacent drainage core segments partially overlap; the drainage holes on the last-stage drainage core segment match with the diversion channels on the diversion core segment; in, M Is a positive integer.

4. The stator core integrated with bent multi-parallel axial micro-channels according to claim 3, characterized in that: The end of the groove on the outer edge of the inlet core segment is an arc; the first and last ends of the drainage core segments at each level are arcs; the first and last ends are respectively the radially outermost and innermost ends; The arc at the end of the groove on the outer edge of the inlet core segment coincides with the center of the arc at the beginning of the hole of the yoke of the adjacent drainage core segment and the apertures are equal; in two adjacent drainage core segments, the arc at the end of the hole of the yoke of the previous drainage core segment coincides with the center of the arc at the beginning of the hole of the yoke of the next drainage core segment and the apertures are equal.

5. The stator core integrated with bent multi-parallel axial micro-channels according to any one of claims 1 to 4, characterized in that: Width of radial converging channel d 1 and the width of the axial flow channel in the parallel core segment d 2 Satisfaction: d 1= N × d 2; The radial converging flow channels include the radial flow channels in the first converging core segment, the radial flow channels in the second core segment, the first converging channel in the diverting core segment, and the second converging channel in the leading core segment.

6. A stator core integrated with a bent axial microchannel, characterized in that: include: The inlet section core and the runner section cores on both sides; Along the axial middle portion to the axial end portion of the stator core, the flow channel section core sequentially includes a first converging core segment, a plurality of parallel core segments, and a second converging core segment. A first converging unit or a second converging unit is provided between every two adjacent parallel core segments, and the first converging units and the second converging units are alternately arranged along the axial direction. Each stator tooth of the parallel core segment is provided with radially arranged K Axial flow channel; K is an odd number, and K ≥3; The first convergence unit includes two first convergence core segments and a yoke flow channel core segment arranged between the two first convergence core segments; in the first convergence core segment, each stator tooth is provided with a first yoke flow channel and radial flow channels, the first yoke flow channel opening matches the axial flow channel closest to the tooth yoke junction in the adjacent parallel core segments, and each radial flow channel is connected to two adjacent axial flow channels in the adjacent parallel core segments; a second yoke flow channel opening matching the first yoke flow channel opening is provided on each stator tooth in the core segment of the yoke flow channel opening; The second convergence unit includes two second convergence core segments and a tooth tip flow channel opening core segment arranged between the two second convergence core segments; in the second convergence core segment, each stator tooth is provided with a first tooth tip flow channel opening and radial flow channels, the first tooth tip flow channel opening matches the axial flow channel closest to the tooth tip in the adjacent parallel core segment, and each radial flow channel is connected to two adjacent axial flow channels in the adjacent parallel core segment; a second tooth tip flow channel opening matching the first tooth tip flow channel opening is provided on each stator tooth in the core segment having the tooth tip flow channel opening; The inlet section core is provided with an inlet flow channel corresponding to each tooth portion one by one. One end of the inlet flow channel is used to inject cooling medium, and the other end is matched with the first yoke flow channel opening on the adjacent first converging core segment.

7. The stator core integrated with bent axial micro-channels according to claim 6, characterized in that: The inlet flow channel on the inlet section iron core is a stepped flow channel.

8. The stator core integrated with bent axial micro-channels according to claim 7, characterized in that: The entrance section core comprises: an entrance core section, the outer edge of which is circumferentially provided with grooves corresponding to the teeth; Each side of the inlet core segment is provided with M The inlet core segment on each side M In the drainage core segments, the yoke of each drainage core segment is provided with drainage holes corresponding to the teeth along the circumference. The drainage holes on the drainage core segments closer to the corresponding side flow channel segment are closer to the junction of the teeth and yoke. The drainage holes on the first-stage drainage core segment partially overlap with the corresponding grooves on the inlet core segment; the corresponding drainage holes on the two adjacent drainage core segments partially overlap; the drainage holes on the last-stage drainage core segment match with the first yoke flow channel opening on the adjacent first converging core segment; in, M Is a positive integer.

9. The stator core integrated with bent axial micro-channels according to claim 8, characterized in that: The end of the groove on the outer edge of the inlet core segment is an arc; the first and last ends of the drainage core segments at each level are arcs; the first and last ends are respectively the radially outermost and innermost ends; The arc at the end of the groove on the outer edge of the inlet core segment coincides with the center of the arc at the beginning of the hole of the yoke of the adjacent drainage core segment and the apertures are equal; in two adjacent drainage core segments, the arc at the end of the hole of the yoke of the previous drainage core segment coincides with the center of the arc at the beginning of the hole of the yoke of the next drainage core segment and the apertures are equal.

10. An aircraft generator, characterized in that: The invention comprises the stator core integrated with bent multiple parallel axial micro-channels as described in any one of claims 1 to 5, or the stator core integrated with bent multiple parallel axial micro-channels as described in any one of claims 6 to 9.

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