High speed aero-generator

Abstract

The application provides a high-speed aircraft generator, and relates to the technical field of generators, which has 12 stator slots on a stator core; four coils of each phase winding are divided into two pairs, and the two coils of each pair are arranged in a central symmetry so that the counter electromotive force generated by the two coils is the same in phase and amplitude; when the rotor is deviated towards the direction of one coil, the magnetic pull on the side of the coil paired with the one coil increases, so as to pull the rotor back to the position coaxial with the stator. The application is a three-phase motor with 2 poles and 12 slots, can maintain the rotor in the position with zero air gap deviation in 12 directions, realizes radial magnetic suspension of the rotor, avoids deviation of the motor due to dynamic reasons, improves the performance of the motor, reduces the friction loss of the rotating shaft and the bearing, reduces the burden of the bearing, and improves the service life of the bearing and the motor. The motor adopts a heat dissipation structure, and has the ability of noise reduction and vibration reduction.

Description

Technical Field

[0001] This invention relates to the field of generator technology, and more specifically, to a high-speed aircraft generator. Background Technology

[0002] A permanent magnet generator (PMG) is a generator that converts mechanical energy into electrical energy by using permanent magnets to provide an excitation magnetic field. When the rotor rotates, the stator windings cut the magnetic lines of force of the permanent magnet, thus converting mechanical energy into electrical energy. The basic structure of a PMG is comprised of a stator, rotor, shaft, and frame. The rotor is coaxially mounted on the shaft, which is rotatably connected to the frame via bearings. The rotor consists of a rotor core and magnets. The stator includes a stator core and windings mounted on it. A drive mechanism drives the shaft to rotate, thereby rotating the rotor. The windings cut the magnetic lines of force of the permanent magnet, generating current and thus producing electricity. PMGs have applications in fields such as aviation.

[0003] Under normal circumstances, the rotor and stator of a permanent magnet generator are coaxial, and the air gap of the motor is uniform. However, during dynamic operation, the rotor may deviate due to some dynamic factors (external airflow disturbance, load fluctuation, vibration and impact), resulting in air gap deviation. Air gap deviation will aggravate rotor vibration, increase core loss and local overheating, thereby causing the motor performance to deteriorate. Summary of the Invention

[0004] The problem solved by this invention is that the rotor is deviated due to dynamic reasons, resulting in air gap deviation and deterioration of motor performance.

[0005] To address the aforementioned problems, this invention provides a high-speed aircraft generator, comprising: a stator and a rotor; the rotor having a pair of magnetic poles; the stator coaxially sleeved outside the rotor; the stator including a stator core and windings; 12 stator slots evenly distributed along the circumference of the stator core; the windings being three-phase windings; each phase of the winding including four coils; one effective edge of each coil embedded in the upper layer of one stator slot, and the other effective edge embedded in the lower layer of another stator slot; two effective edges belonging to different coils within each stator slot are stacked radially along the stator core; the span of each coil is 5 slots; the four coils of each phase winding are divided into two pairs, and the two coils in each pair are arranged symmetrically about the center of the stator core so that the back electromotive force generated by the two coils has the same phase and amplitude. One effective side of one of the coils in the first pair and one effective side of one of the coils in the second pair are located in the same stator slot, and the two coils are located on both sides of a diameter of the stator core. The number of turns and the geometry of each coil are the same, so that when the rotor is deflected toward one of the coils, the magnetic pull on the side of the coil paired with that coil increases, so as to pull the rotor back to a position coaxial with the stator. The three-phase windings are arranged in the same way. The stator slot that accommodates the effective side of the two first ends connected by each phase winding is called the first end stator slot. The three first end stator slots corresponding to the three-phase windings are evenly spaced along the circumference of the stator core. The corresponding ports of the four coils of each phase winding are connected to each other to form the lead-out end and the convergence point of the corresponding phase. The convergence points of each phase are connected to each other to form a common neutral point. The rotor includes a rotor core, an N-pole permanent magnet, and an S-pole permanent magnet. The polar arc coefficient of both the N-pole and S-pole permanent magnets is 1. The N-pole and S-pole permanent magnets are distributed at intervals along the circumference of the rotor core and are attached to the outer peripheral wall of the rotor core. The N-pole and S-pole permanent magnets are arranged in a centrally symmetrical manner with the center of the rotor core as the center of symmetry.

[0006] Optionally, the stator core is formed by axially stacking silicon steel sheets with a thickness of 0.1 to 0.2 mm.

[0007] Optionally, the N-pole permanent magnet and the S-pole permanent magnet are fixed to the outer peripheral wall of the rotor core by insulating adhesive.

[0008] Optionally, the rotor further includes a carbon fiber sleeve; the carbon fiber sleeve is sleeved outside the N-pole permanent magnet and the S-pole permanent magnet and fixed to the N-pole permanent magnet and the S-pole permanent magnet.

[0009] Optionally, both the N-pole permanent magnet and the S-pole permanent magnet include multiple sub-magnets; the multiple sub-magnets constituting the same magnetic pole are distributed in a 5×5 array along the circumference and axial direction of the rotor core; adjacent sub-magnets constituting the same magnetic pole are fixed by insulating adhesive.

[0010] Optionally, the stator is provided with a heat dissipation structure; the heat dissipation structure includes a heat dissipation shell and a heat dissipation shroud, both of which are cylindrical; the heat dissipation shell is sleeved on the outside of the stator core and is fixedly fitted to the outer peripheral wall of the stator core; the heat dissipation shroud is coaxially sleeved on the outside of the heat dissipation shell and is fixedly connected to the stator core; a plurality of first heat dissipation ribs are evenly distributed along the circumference of the outer peripheral wall of the heat dissipation shell; a plurality of second heat dissipation ribs are evenly distributed along the circumference of the inner peripheral wall of the heat dissipation shroud; the first heat dissipation ribs and the second heat dissipation ribs are both long strip-shaped structures extending along the axial direction of the stator core; the plurality of first heat dissipation ribs and the plurality of second heat dissipation ribs are arranged alternately along the circumference of the stator core.

[0011] Optionally, one end of the heat dissipation shroud is a horn-shaped structure; the horn-shaped structure expands outward along the axis away from the stator core.

[0012] Optionally, the carbon fiber sleeve is formed by tensioning and winding carbon fiber bundles and simultaneously curing resin during the winding process.

[0013] Optionally, the carbon fiber sleeve has a thickness of 3 mm. The outer diameter of the stator core is 206 mm; the inner diameter of the stator core is 143 mm; the width of the stator teeth of the stator core is 15 mm; and the width of the stator yoke of the stator core is 16 mm.

[0014] Optionally, the stator core and the rotor core have the same length, and the two ends of the stator core and the rotor core are aligned.

[0015] The beneficial effects of the high-speed aircraft generator of the present invention are: The high-speed aviation generator provided by this invention is a three-phase motor with 2 poles and 12 slots. Each phase includes two pairs of coils, enabling the rotor to maintain a position with zero air gap deviation in all 12 directions. This achieves radial magnetic levitation of the rotor, preventing motor misalignment due to dynamic factors and improving motor performance. Simultaneously, because this invention enables radial magnetic levitation of the rotor, the shaft can automatically overcome its own weight and position itself coaxial with the stator. This reduces the force on the bearings supporting the shaft, weakening their supporting function and reducing their actual load. This reduces the bearing's burden, lowers frictional losses, and prevents increased clearance between the bearing and the shaft due to wear. This also reduces maintenance requirements and extends the service life of both the bearings and the motor. This invention, through optimized motor design, achieves a high-speed, high-power generator. Attached Figure Description

[0016] Figure 1 A schematic diagram of the stator and rotor in a high-speed aircraft generator provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the stator in a high-speed aircraft generator provided in an embodiment of the present invention; Figure 3 A cross-sectional view of the rotor in a high-speed aircraft generator provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the heat dissipation structure in a high-speed aircraft generator provided in an embodiment of the present invention; Figure 5 This is another schematic diagram of the heat dissipation structure in a high-speed aircraft generator provided in an embodiment of the present invention.

[0017] Explanation of reference numerals in the attached figures: 1. Stator core; 2. Effective edge; 3. Rotor core; 4. Sub-magnet; 5. Stator; 6. Heat sink; 7. Heat sink shroud; 8. First heat sink fin; 9. Second heat sink fin; 10. Rotor; 11. Shaft. Detailed Implementation

[0018] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0019] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0020] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0021] like Figures 1 to 2 As shown in the figure, an embodiment of the present invention provides a high-speed aircraft generator, which includes: a stator 5 and a rotor 10; the rotor 10 has a pair of magnetic poles; the stator is coaxially sleeved on the outside of the rotor; the stator 5 includes a stator core 1 and windings; the stator core 1 has 12 stator slots evenly distributed along its circumference; the windings are three-phase windings (e.g., Figure 2 As shown, these are windings A, B, and C (with letter O indicating the neutral point). Each phase winding includes four coils. One effective side 2 of each coil is embedded in the upper layer of one stator slot, and the other effective side 2 is embedded in the lower layer of another stator slot. The two effective sides 2 belonging to different coils within each stator slot are stacked radially along the stator core 1. The span of each coil is 5 slots. The four coils of each phase winding are divided into two pairs. The two coils in each pair are arranged symmetrically with the center of the stator core 1 as the center of symmetry so that the back EMF generated by the two coils has the same phase and amplitude. One effective side 2 of one coil in the first pair is connected to one effective side 2 of one coil in the second pair. 2 are located in the same stator slot, and the two coils are located on both sides of a diameter of the stator core 1. The number of turns and the geometric shape of each coil are the same, so that when the rotor 10 is offset toward the direction of a coil, the magnetic pull on the coil side paired with that coil increases, so as to pull the rotor 10 back to the position coaxial with the stator 5; the three-phase windings are arranged in the same way; the stator slot that accommodates the effective side 2 of the two first ends connected by each phase winding is called the first end stator slot; the three first end stator slots corresponding to the three-phase windings are evenly distributed along the circumference of the stator core 1; the same-name ports of the four coils of each phase winding are connected to each other to form the lead-out end and the convergence point of the corresponding phase respectively; the convergence points of each phase are connected to each other to form a common neutral point. The rotor 10 includes a rotor core 3, an N-pole permanent magnet, and an S-pole permanent magnet. The pole arc coefficients of the N-pole and S-pole permanent magnets are both 1. The N-pole and S-pole permanent magnets are distributed at intervals along the circumference of the rotor core 3 and attached to the outer circumferential wall of the rotor core 3. The N-pole and S-pole permanent magnets are arranged in a centrally symmetrical manner with the center of the rotor core 3 as the center of symmetry.

[0022] Figure 2 This is a schematic diagram of the stator 5 provided by the present invention. For ease of description, the 24 effective edges 2 are numbered 1 to 24 in a counterclockwise direction. A "+" sign indicates current inflow, and "o" indicates current outflow. The line connecting two effective edges 2 is only a schematic representation of the coils corresponding to those two effective edges 2, and does not refer to the ends between the two effective edges 2.

[0023] One effective side 2 of each coil is located in one stator slot, and the other effective side 2 is located in another stator slot. The portion between the two effective sides 2 (end connection line) is located outside the end face of the stator core 1. This structure is the standard arrangement of the windings of a permanent magnet generator. Therefore, it is not shown in the figure for better illustration of the principle of the invention.

[0024] N-pole permanent magnets and S-pole permanent magnets are distributed at intervals along the circumference of the rotor core 3 and are attached to the outer circumferential wall of the rotor core 3, that is, the rotor 10 is a surface-mounted rotor.

[0025] Specifically, the motor of this invention uses surface-mounted, full-pole-pitch (the pole arc coefficient of both the N-pole and S-pole permanent magnets is 1) magnets, and the quadrature and direct axes of the motor are completely symmetrical. Any coil element in the three-phase windings has the same number of turns and geometric shape (geometric shape refers to diameter, length, and winding direction). These pre-fabricated winding elements are embedded into the corresponding stator slots according to the above arrangement. This ensures the consistency of the resistance, inductance, mutual inductance, and leakage inductance of the three-phase windings, and the air gap between the stator 5 and rotor 10 is uniform with zero radial deviation. When the motor rotates, it ensures that the back EMF amplitude and phase are the same in the four coils of each phase winding. Tests have shown that the deviation is better than 0.2%.

[0026] During operation, the rotor 10 is fixedly mounted on the shaft 11, which is rotatably connected to the base via bearings. The shaft 11 rotates, driving the rotor 10 to rotate. The windings of the stator 5 cut magnetic field lines and generate a corresponding current, thus achieving power generation. Under normal conditions, the rotor 10 and stator 5 are coaxial, with a uniform air gap, and the magnetic pull on the rotor 10 is balanced (the magnetic pull generated by each pair of coils is the same). Each phase winding has four coils, divided into two pairs, each pair consisting of two coils. For example, in phase A windings, coils 3-12 and 24-15 form one pair, and coils 1-10 and 22-13 form another pair. Each coil has a 5-slot span, meaning there are 4 stator slots between the two effective edges 2 of each coil. For example, in coil 3-12, there are 4 stator slots between the effective edges 2 of coil 3 and 12. The two coils in each pair are arranged symmetrically with the center of the stator core 1 as the center of symmetry so that the back electromotive force generated by the two coils has the same phase and amplitude (the number of turns, diameter, length, span and winding direction of the two coils are consistent). That is, in each pair of coils, one coil is rotated 180° and then coincides with the other coil. For example, coil 3-12 is rotated 180° and then coincides with coil 24-15. Furthermore, since the number of turns and geometric shape of the coils are the same, the even-order magnetomotive force generated by the two coils in each pair is equal in magnitude and opposite in phase, thus canceling each other out. This cancels out the even-order magnetomotive force harmonics and balances the air gap magnetic field distribution. At the same time, the back electromotive force generated by the two coils in each pair has the same phase and amplitude, and the magnetic pull on both sides of the rotor 10 is the same. The rotor 10 is located at the center position between the two coils, that is, the rotor 10 and the stator 5 are coaxial.

[0027] When the rotor 10 shifts towards one of the coils due to dynamic reasons (external airflow disturbance, load fluctuation, vibration impact), the air gap on the coil side decreases, and the air gap on the coil side paired with that coil increases. On the side with the smaller air gap, the magnetic reluctance decreases (according to the magnetic reluctance calculation formula, the smaller the air gap, the smaller the magnetic reluctance), the magnetic flux passing through the coil on that side increases (according to the magnetic flux calculation formula, the smaller the magnetic reluctance, the larger the magnetic flux), the back electromotive force induced in that coil increases (according to the back electromotive force calculation formula, at constant speed, the larger the magnetic flux, the larger the back electromotive force), the current in that coil decreases (with a constant applied voltage, the larger the back electromotive force, the smaller the current), and the magnetic pull on that side decreases (because the current decreases, the armature magnetic field generated by the coil decreases, and the magnetic pull generated by the interaction between the armature magnetic field generated by the coil and the permanent magnetic field generated by the permanent magnet of the rotor 10 decreases, that is, the radial magnetic pull on the rotor 10 towards the coil on that side decreases). Conversely, on the side with a larger air gap, the magnetic reluctance increases, the magnetic flux through the coil on that side decreases, the induced back electromotive force in that coil decreases, the current in that coil increases, and the magnetic pull on that side increases (i.e., the radial magnetic pull on the rotor 10 towards the coil on that side increases). In other words, the magnetic pull on the side with a smaller air gap decreases, and the magnetic pull on the side with a larger air gap increases. The rotor 10 (since the rotor 10 is fixed to the shaft 11, the rotor 10 and the shaft 11 move together) moves towards the side with a larger air gap under the action of the two magnetic pull forces until the magnetic pull forces on both sides of the rotor 10 are equal. At this point, the rotor 10 is located in the middle position of the two coils, that is, the rotor 10 is coaxial with the stator 5.

[0028] like Figure 2 As shown, taking the paired coils 3-12 and 24-15 as an example, when the rotor 10 shifts towards coil 3-12, the air gap on the coil 3-12 side decreases, while the air gap on the coil 24-15 side increases. The magnetic reluctance on the coil 3-12 side decreases, the magnetic flux through coil 3-12 increases, the induced back electromotive force on coil 3-12 increases, the current in coil 3-12 decreases, and the magnetic pull on the coil 3-12 side decreases. Conversely, the magnetic reluctance on the coil 24-15 side increases, the magnetic flux through coil 24-15 decreases, the induced back electromotive force on coil 24-15 decreases, the current in coil 24-15 increases, and the magnetic pull on the coil 24-15 side increases. At this time, the magnetic pull on the coil 24-15 side is greater than the magnetic pull on the coil 3-12 side. Under the combined action of the magnetic pulls of coil 3-12 and coil 24-15, the rotor 10 moves toward the coil 24-15 side, that is, toward the side where the air gap is larger, until the magnetic pulls on the rotor 10 from the coil 3-12 side and the coil 24-15 side are the same. At this time, the rotor 10 is located in the middle position between coil 3-12 and coil 24-15, that is, the rotor 10 is coaxial with the stator 5.

[0029] One effective side 2 of one coil in the first pair and one effective side 2 of one coil in the second pair are located in the same stator slot, and the two coils are located on opposite sides of a diameter of the stator core 1. For example, as Figure 2 As shown, in the A-phase winding, the effective side 2 of label 1 and the effective side 2 of label 24 are located in the same stator slot. Since the two coils corresponding to these two effective sides 2 are located on both sides of a diameter of the stator core 1, the effective side 2 of label 12 and the effective side 2 of label 13 are also located in the same stator slot.

[0030] The three-phase windings are arranged in the same way; the stator slots that accommodate the effective side 2 connecting the two start ends of each phase winding are called start end stator slots; the three start end stator slots corresponding to the three-phase windings are evenly spaced along the circumference of the stator core 1. For example, as Figure 2 As shown, in phase A winding, the first stator slots are the stator slots containing effective sides 2 of number 1 and 24; in phase B winding, the first stator slots are the stator slots containing effective sides 2 of number 8 and 9; and in phase C winding, the first stator slots are the stator slots containing effective sides 2 of number 16 and 17. These three first stator slots are evenly spaced along the circumference of the stator core 1, that is, the three first stator slots are spaced three stator slots apart from each other. This arrangement ensures that the 12 coils are precisely arranged in the 12 stator slots according to the arrangement of this invention.

[0031] The corresponding terminals of the four coils in each phase winding are connected to each other (i.e., the four coils are connected in parallel) to form the lead-out terminals and convergence points of the corresponding phases; the convergence points of each phase are connected to form a common neutral point. For example, as Figure 2 As shown, in phase A winding, the effective sides 2 of numbers 1, 3, 22, and 24 are connected together to form the phase A lead-out terminal, and the effective sides 2 of numbers 10, 12, 13, and 15 are connected together to form the phase A convergence point. In phase B winding, the effective sides 2 of numbers 6, 8, 9, and 11 are connected together to form the phase B lead-out terminal, and the effective sides 2 of numbers 18, 20, 21, and 23 are connected together to form the phase B convergence point. In phase C winding, the effective sides 2 of numbers 14, 16, 17, and 19 are connected together to form the phase C lead-out terminal, and the effective sides 2 of numbers 2, 4, 5, and 7 are connected together to form the phase C convergence point. The phase A convergence point, phase B convergence point, and phase C convergence point are interconnected to form a common neutral point.

[0032] This invention has three phases, with two pairs of coils per phase, totaling six pairs of coils. When the rotor 10 deviates towards one of the six pairs of coils, it can automatically return to its coaxial position with the stator 5. In other words, when the rotor 10 deviates towards any of the 12 coils, it can automatically return to its original position, eliminating air gap deviation. In all 12 directions, the rotor 10's own weight can be overcome to maintain it at a position with zero air gap deviation, achieving radial magnetic levitation of the rotor 10.

[0033] The high-speed aviation generator provided by this invention is a three-phase motor with 2 poles and 12 slots. Each phase includes two pairs of coils, enabling the rotor 10 to be maintained at a position with zero air gap deviation in 12 directions, achieving radial magnetic levitation of the rotor 10. This prevents the motor from deviating due to dynamic factors, thus improving motor performance. Simultaneously, because this invention enables radial magnetic levitation of the rotor 10, the shaft 11 can also overcome its own weight and automatically position itself coaxial with the stator 5. This reduces the force on the bearings supporting the shaft 11, weakening their supporting function and reducing the actual load on the bearings. This reduces the bearing's burden, lowers frictional losses between the shaft 11 and the bearings, and prevents increased clearance between the bearings and the shaft 11 due to bearing wear, reducing maintenance requirements and extending the service life of the bearings and the motor. Since this invention's motor uses four parallel branches (four coils in each phase), the number of turns in each phase winding is increased by four times, and the radial restoring force is increased by 16 times. Increasing the number of turns in the winding elements significantly improves the tolerance of the number of turns and machining, which is beneficial for motor manufacturing.

[0034] Optionally, the stator core 1 is formed by axially stacking silicon steel sheets with a thickness of 0.1 to 0.2 mm.

[0035] In this optional embodiment, eddy current losses are induced within the silicon steel sheet when the alternating magnetic flux passes through it. As shown by the eddy current loss formula, eddy current loss is proportional to the square of the silicon steel sheet thickness; that is, the smaller the silicon steel sheet thickness, the smaller the eddy current loss. Therefore, reducing the thickness of the silicon steel sheet can shorten the eddy current flow path and suppress the eddy current amplitude.

[0036] This invention uses 0.1~0.2 mm thick silicon steel sheets (ultra-thin silicon steel sheets) stacked axially to form the stator core 1. Compared with existing permanent magnet generators (with 0.35 mm thick silicon steel sheets), this reduces the thickness of the silicon steel sheets, significantly reduces eddy current losses in the stator core 1, reduces heat generation in the stator 5, and thus improves motor efficiency. Experiments have shown that compared with using 35WW250 (0.35 mm thick non-oriented silicon steel, 250 being an iron loss rating), iron losses can be reduced by 40%–50%.

[0037] Optionally, the N-pole permanent magnet and the S-pole permanent magnet are fixed to the outer peripheral wall of the rotor core 3 by insulating adhesive.

[0038] In this optional embodiment, the insulating adhesive forms an effective electrical barrier between the magnet and the rotor core 3, cutting off the eddy current loop, significantly reducing eddy current losses, and improving motor efficiency.

[0039] Optionally, the rotor 10 further includes a carbon fiber sleeve; the carbon fiber sleeve is sleeved on the N-pole permanent magnet and the S-pole permanent magnet and fixed to the N-pole permanent magnet and the S-pole permanent magnet.

[0040] In this optional embodiment, the magnet is attached to the outside of the rotor core 3. When the rotor 10 rotates, the magnet generates centrifugal force outward, which poses a risk of the magnet falling off. A carbon fiber sleeve is installed around the magnet. The carbon fiber sleeve constrains the magnet, and the circumferential tensile stress generated by the magnet on the carbon fiber sleeve can counteract the centrifugal load on the magnet, thereby improving the magnet's resistance to centrifugal force and enhancing the reliability of the rotor 10 during high-speed operation. Furthermore, carbon fiber is a non-magnetic material and will not induce eddy current losses within the sleeve.

[0041] like Figure 1 and Figure 3 As shown, optionally, both the N-pole permanent magnet and the S-pole permanent magnet include multiple sub-magnets 4; the multiple sub-magnets 4 constituting the same magnetic pole are distributed in a 5×5 array along the circumference and axial direction of the rotor core 3; two adjacent sub-magnets 4 constituting the same magnetic pole are fixed by insulating glue.

[0042] In this optional embodiment, both the N-pole and S-pole permanent magnets are composed of 25 sub-magnets 4, which are arranged in a 5×5 array along the circumference and axial direction of the rotor core 3. Adjacent sub-magnets 4 forming the same magnetic pole are fixed with insulating glue. This effectively divides the large N-pole and S-pole permanent magnets into multiple smaller sub-magnets 4. Due to the presence of a high-frequency alternating harmonic magnetic field in the air gap, eddy currents are induced inside the permanent magnet when the magnetic field penetrates it. The entire permanent magnet can form a large-area closed eddy current loop, resulting in high eddy current losses. Dividing the large N-pole and S-pole permanent magnets into several smaller magnets and filling the gaps between adjacent smaller magnets with insulating glue to achieve electrical isolation cuts off the large-scale eddy current path across the magnet blocks, confining the eddy currents within a single smaller magnet, reducing the eddy current loop area, effectively reducing the eddy current losses of the permanent magnet, and allowing the motor to output the maximum power within its design capacity. Experiments have shown that it can reduce rotor losses by about 30%, and the motor dynamic balance accuracy reaches G0.4 level (according to ISO1940-1 standard), with the remaining imbalance ≤0.1g·mm.

[0043] like Figure 4 and Figure 5 As shown, Figure 4The arrows in the diagram indicate the direction of airflow. Optionally, the stator 5 is provided with a heat dissipation structure; the heat dissipation structure includes a heat dissipation shell 6 and a heat dissipation shroud 7, both of which are cylindrical; the heat dissipation shell 6 is sleeved on the outside of the stator core 1 and is fixedly fitted to the outer peripheral wall of the stator core 1; the heat dissipation shroud 7 is coaxially sleeved on the outside of the heat dissipation shell 6 and is fixedly connected to the stator core 1; a plurality of first heat dissipation ribs 8 are evenly spaced along the circumference of the outer peripheral wall of the heat dissipation shell 6; a plurality of second heat dissipation ribs 9 are evenly spaced along the circumference of the inner peripheral wall of the heat dissipation shroud 7; the first heat dissipation ribs 8 and the second heat dissipation ribs 9 are both long strip-shaped structures extending along the axial direction of the stator core 1; the plurality of first heat dissipation ribs 8 and the plurality of second heat dissipation ribs 9 are arranged alternately along the circumference of the stator core 1.

[0044] Specifically, both the heat sink 6 and the first heat sink 8 are made of aluminum.

[0045] In this optional embodiment, the heat from the stator 5 is transferred to the heat sink 6 and the first heat sink fin 8. Airflow enters the heat sink shroud 7, carrying away the heat from the heat sink 6 and the first heat sink fin 8, thus cooling the heat sink 6 and the first heat sink fin 8, thereby achieving the cooling function of the stator 5. The first heat sink fin 8 and the second heat sink fin 9 vibrate when the rotor 10 rotates. Because the first heat sink fin 8 and the second heat sink fin 9 are staggered along the circumference of the stator core 1, the phases of the sound waves generated by the vibration of the first heat sink fin 8 and the second heat sink fin 9 cancel each other out, thereby reducing the noise and vibration of the heat dissipation structure.

[0046] Optionally, one end of the heat dissipation shroud 7 is a trumpet-shaped structure; the trumpet-shaped structure is inclined and expanded outward along the axis away from the stator core 1.

[0047] In this optional embodiment, one end of the heat dissipation shroud 7 is a horn-shaped structure, which can guide external airflow smoothly into the shroud.

[0048] Optionally, the carbon fiber sleeve is formed by tensioning and winding carbon fiber bundles and simultaneously curing resin during the winding process.

[0049] In this optional embodiment, the carbon fiber sleeve is formed by tensioning and winding carbon fiber bundles, which simultaneously cures during the winding process. Specifically, continuous carbon fiber bundles are stretched under a preset tension, wrapping around the outer circumference of the magnet layer by layer. Resin is impregnated during winding, and the process is simultaneously heated and cured, resulting in a single, integrated carbon fiber sleeve. This ensures that the carbon fiber bundles remain under tension during winding, and stable tensile stress remains within the fibers after the resin cures. This creates a uniform and continuous radial pre-tightening constraint force on the inner permanent magnet, resulting in a tight fit between the sleeve and the magnet surface. The circumferential clamping force is evenly distributed, reducing the risk of localized stress concentration, improving centrifugal force resistance, and enhancing the structural reliability of the rotor 10 under long-term high-speed operation and alternating vibration conditions. Compared to steel sleeves, centrifugal force resistance can be increased by 50%, making it suitable for high-speed motors.

[0050] Optionally, the carbon fiber sleeve has a thickness of 3 mm. The outer diameter of stator core 1 is 206 mm; the inner diameter of stator core 1 is 143 mm. The width of the stator teeth of stator core 1 is 15 mm, and the width of the stator yoke of stator core 1 is 16 mm.

[0051] In this optional embodiment, a 3 mm thick carbon fiber sleeve provides sufficient cross-sectional area to withstand the centrifugal load generated by the permanent magnet during high-speed operation, continuously providing a uniform inward radial preload constraint force. Simultaneously, the sleeve thickness does not excessively occupy the motor's air gap space, preventing excessive increases in air gap magnetic reluctance and ensuring the air gap flux's sensitivity to rotor 10 eccentricity changes. This facilitates monitoring rotor 10 offset using the back EMF difference of the stator 5's symmetrical coils. Furthermore, this thickness is compatible with the carbon fiber bundle tensioning, winding, and synchronous curing molding process, facilitating control of the uniformity of preload stress within the sleeve and reducing the risk of molding defects.

[0052] The stator core 1 has an outer diameter of 206 mm and an inner diameter of 143 mm. This size ratio gives the stator core 1 a radial width of 31.5 mm, which on the one hand ensures that the back yoke of the stator 5 has sufficient magnetic cross-sectional area to avoid magnetic saturation during magnetic flux operation and ensure smooth magnetic circuit; on the other hand, it provides enough space for the stator slots to facilitate the arrangement of the stator 5 coils. The inner diameter of the stator 5 can match the structure of the rotor 10 to form a reasonable basic air gap, taking into account both the assembly safety of the rotor 10 and the sensitivity of the air gap magnetic flux to the eccentricity changes of the rotor 10, which is conducive to monitoring the rotor 10 offset through the back electromotive force difference of the symmetrical coils; the outer diameter of the stator 5 ensures that the outer side of the core has sufficient heat dissipation area, while improving the rigidity of the stator 5 ring structure and suppressing electromagnetic vibration.

[0053] The stator teeth are 15 mm wide, and the stator yoke is 16 mm wide, ensuring a matching magnetic flux density. This means that during motor operation, the magnetic flux density of the stator teeth and the stator yoke is essentially equal, preventing imbalances such as "teeth unsaturated, yoke saturated first" or "yoke surplus, teeth saturated first." The entire magnetic circuit exhibits uniform magnetic reluctance distribution, fully utilizing the low iron loss advantage of the 0.1~0.2 mm ultra-thin silicon steel sheets to minimize overall core loss.

[0054] Optionally, the stator core 1 and the rotor core 3 have the same length, and the two ends of the stator core 1 and the rotor core 3 are aligned.

[0055] In this optional embodiment, the stator core 1 and the rotor core 3 have the same length and are aligned at both ends, so that the air gap magnetic reluctance of the magnetic circuit is minimized in the axial direction, and has an axial self-centering tendency, which helps to reduce axial magnetic pull fluctuation.

[0056] As an example, the stator core or rotor core has an outer diameter of 185 mm and a length of 260 mm.

[0057] In one specific embodiment, the specific parameters of the high-speed aircraft generator provided by the present invention are as follows: Operating frequency: 833Hz (corresponding to a speed of 50000RPM).

[0058] Stator 5 material: 0.1mm ultra-thin silicon steel sheet.

[0059] Permanent magnet material: NEOMAX-48BH (NEOMAX: Hitachi Metals Commercial Neodymium Iron Boron series name, 48: remanence grade; BH: represents high coercivity and high temperature resistance grade).

[0060] Winding type: Low-loss Litz wire winding (Φ0.1×250 wire).

[0061] Stator 5 outer diameter: 206mm, inner diameter: 143mm.

[0062] Stator core stack length: 190mm.

[0063] Number of stator slots: 12.

[0064] The width of the stator teeth of stator core 1 is 15mm, and the width of the stator yoke is 16mm.

[0065] The high-speed aircraft generator provided by this invention can achieve the following beneficial effects: 1. This invention achieves a high-speed, high-power generator through optimized motor design. The motor can reach over 300 kilowatts, rotate at 50,000 revolutions per minute, and has an efficiency better than 97%, with a maximum efficiency of 98.7%, significantly higher than traditional motors.

[0066] 2. The motor body has a power density of up to 8.3kW / kg, achieving a lightweight design with high power density.

[0067] 3. Natural magnetic levitation technology overcomes the self-weight of the motor rotor, allowing the bearings to be derated as auxiliary bearings, thus greatly improving the service life of the motor.

[0068] 4. The carbon fiber sleeve increases the rotor's resistance to centrifugal force by 50%, meeting the requirements of extreme working conditions with a linear speed of 250m / s.

[0069] The use of 5.0.1mm silicon steel sheets reduces high-frequency iron loss by 40%-50%.

[0070] 6. The segmented magnetic isolation design of the permanent magnet reduces rotor losses by approximately 30%.

[0071] 7. The innovative heat dissipation structure not only improves heat dissipation efficiency but also reduces noise by utilizing the principle of acoustic wave phase cancellation.

[0072] 8. The dynamic balancing accuracy reaches G0.4 grade (ISO1940-1), and the remaining imbalance is ≤0.1g·mm, ensuring the stability of high-speed operation.

[0073] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A high-speed aircraft generator, characterized in that, include: Stator (5) and rotor (10); The rotor (10) has a pair of magnetic poles; the stator (5) is coaxially sleeved outside the rotor (10); the stator (5) includes a stator core (1) and windings; 12 stator slots are evenly distributed along the circumference of the stator core (1); The winding is a three-phase winding; each phase of the winding includes four coils; one effective side (2) of each coil is embedded in the upper layer of one stator slot, and the other effective side (2) is embedded in the lower layer of another stator slot; the two effective sides (2) belonging to different coils in each stator slot are stacked radially along the stator core (1); the span of each coil is 5 slots; The four coils of each phase winding are divided into two pairs. The two coils of each pair are arranged in a centrally symmetrical manner with the center of the stator core (1) as the center of symmetry so that the back EMF generated by the two coils has the same phase and amplitude. One effective side (2) of one of the coils in the first pair and one effective side (2) of one of the coils in the second pair are located in the same stator slot. The two coils are located on both sides of a diameter of the stator core (1). The number of turns and the geometric shape of each coil are the same so that when the rotor (10) is offset toward one of the coils, the magnetic pull on the coil side paired with that coil increases, so as to pull the rotor (10) back to the position coaxial with the stator (5). The three-phase windings are arranged in the same way; the stator slot that accommodates the effective side (2) connecting the two ends of each phase winding is called the first end stator slot; the three first end stator slots corresponding to the three-phase windings are evenly spaced along the circumference of the stator core (1). The corresponding terminals of the four coils of each phase winding are interconnected to form the lead-out terminal and the convergence point of the corresponding phase, respectively; the convergence points of each phase are interconnected to form a common neutral point; The rotor (10) includes a rotor core (3), an N-pole permanent magnet, and an S-pole permanent magnet; The polar arc coefficients of the N-pole permanent magnet and the S-pole permanent magnet are both 1. The N-pole permanent magnet and the S-pole permanent magnet are distributed at intervals along the circumference of the rotor core (3) and attached to the outer circumferential wall of the rotor core (3). The N-pole permanent magnet and the S-pole permanent magnet are arranged in a centrally symmetrical manner with the center of the rotor core (3) as the center of symmetry.

2. The high-speed aircraft generator according to claim 1, characterized in that, The stator core (1) is made of silicon steel sheets with a thickness of 0.1~0.2 mm stacked axially.

3. The high-speed aircraft generator according to claim 1, characterized in that, The N-pole permanent magnet and the S-pole permanent magnet are fixed to the outer peripheral wall of the rotor core (3) by insulating glue.

4. The high-speed aircraft generator according to claim 3, characterized in that, The rotor (10) also includes a carbon fiber sleeve; The carbon fiber sleeve is fitted over the N-pole permanent magnet and the S-pole permanent magnet and is fixed to the N-pole permanent magnet and the S-pole permanent magnet.

5. The high-speed aircraft generator according to claim 4, characterized in that, Both the N-pole permanent magnet and the S-pole permanent magnet include multiple sub-magnets (4). Multiple sub-magnets (4) constituting the same magnetic pole are arranged in a 5×5 array along the circumference and axial direction of the rotor core (3); two adjacent sub-magnets (4) constituting the same magnetic pole are fixed by insulating glue.

6. The high-speed aircraft generator according to claim 1, characterized in that, The stator (5) is provided with a heat dissipation structure; the heat dissipation structure includes a heat dissipation shell (6) and a heat dissipation shroud (7), both of which are cylindrical. The heat dissipation shell (6) is sleeved on the outside of the stator core (1) and is fixedly attached to the outer peripheral wall of the stator core (1); the heat dissipation shroud (7) is coaxially sleeved on the outside of the heat dissipation shell (6) and is fixedly connected to the stator core (1). The outer peripheral wall of the heat sink (6) is evenly spaced with a plurality of first heat sink ribs (8) along its circumference; the inner peripheral wall of the heat sink shroud (7) is evenly spaced with a plurality of second heat sink ribs (9) along its circumference; the first heat sink ribs (8) and the second heat sink ribs (9) are both long strip plate-shaped structures extending along the axial direction of the stator core (1). Multiple first heat dissipation fins (8) and multiple second heat dissipation fins (9) are arranged alternately along the circumference of the stator core (1).

7. The high-speed aircraft generator according to claim 6, characterized in that, One end of the heat dissipation shroud (7) is a trumpet-shaped structure; the trumpet-shaped structure is inclined and expanded outward along the axis away from the stator core (1).

8. The high-speed aircraft generator according to claim 4, characterized in that, The carbon fiber sleeve is formed by tensioning and winding carbon fiber bundles and simultaneously curing resin during the winding process.

9. The high-speed aircraft generator according to claim 8, characterized in that, The carbon fiber sleeve has a thickness of 3 mm; the stator core (1) has an outer diameter of 206 mm; the stator core (1) has an inner diameter of 143 mm; the stator teeth of the stator core (1) have a width of 15 mm; and the stator yoke of the stator core (1) has a width of 16 mm.

10. The high-speed aircraft generator according to claim 1, characterized in that, The stator core (1) and the rotor core (3) have the same length, and the two ends of the stator core (1) and the rotor core (3) are aligned.

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