Systems and methods for rotor assemblies and manufacture thereof

Abstract

A rotor assembly includes a sleeve, a rotor hub, and a plurality of conical magnets circumferentially disposed around the inner diameter of the sleeve. The plurality of conical magnets are configured to abut against each other. The plurality of conical magnets includes a first set of conical magnets and a second set of conical magnets. Axial insertion of the first set of conical magnets relative to the second set of conical magnets is configured to increase the diameter of the sleeve. The rotor hub is configured to hold at least one of the plurality of conical magnets or the sleeve.

Description

[0001] This application is a divisional application of the international application filed on December 29, 2023, with international application number PCT / US2023 / 086455, national application number 202380098156.5, entitled "Systems and methods for manufacturing rotor assemblies thereto" which has entered the Chinese national phase.

[0002] Cross-references to related applications

[0003] This disclosure claims priority and interest in U.S. Application No. 18 / 316,931 (Agent No. 16163.0033-00000), filed May 12, 2023, entitled “ROTOR ASSEMBLY INCLUDING TAPEREDMAGNETS WITHIN A RETAINING SLEEVE AND A METHOD FOR ASSEMBLING THE SAME”. U.S. Application No. 18 / 316,931 also claims priority and interest in U.S. Provisional Application No. 63 / 378,536 (Agent No. 16163.6002-00000), filed October 6, 2022, entitled “Tilt Rotor Systems and Methods for eVTOL Aircraft”, and U.S. Provisional Application No. 63 / 378,680 (Agent No. 16163.6002-00000), filed October 7, 2022, entitled “Systems and Methods for Improved Propulsion Systems for eVTOL Aircraft”. For all purposes, the entire contents of the aforementioned application are incorporated herein by reference. Technical Field

[0004] This disclosure relates generally to the field of powered aircraft. More specifically, but not limited to, this disclosure relates to innovations in aircraft powered by electric propulsion systems. Certain aspects of this disclosure generally relate to improvements in rotor assemblies for electric engines and methods of assembling said rotor assemblies, which can be used in aircraft and other types of aircraft powered by electric propulsion systems. Summary of the Invention

[0005] This disclosure proposes systems, components, and techniques primarily for unconventional aircraft powered by electric propulsion systems. For example, the tiltrotor aircraft of this disclosure can be configured for frequent (e.g., more than 50 flights per workday), short-duration flights (e.g., less than 100 miles per flight) over, into, and out of densely populated areas. The aircraft can be configured to carry 4 to 6 passengers or commuters who desire a comfortable experience with low noise and vibration. Therefore, it may be necessary for aircraft components to be configured and designed to withstand frequent use without wear, to generate less heat and vibration, and for the aircraft to include mechanisms for effectively controlling and managing the heat or vibration generated by the components. Additionally, it may be anticipated that several of these aircraft will operate close to each other over congested metropolitan areas. Therefore, it may be necessary for their components to be configured and designed to generate low levels of noise both inside and outside the aircraft, and to be configured and designed with various safety and backup mechanisms. For example, for safety reasons, the aircraft may need to be propelled by a distributed propulsion system to avoid the risk of single points of failure, and the aircraft may need to be able to take off and land routinely on runways. Furthermore, when transporting multiple passengers or commuters with baggage, aircraft may need to be able to take off and land vertically from and onto spaces that are relatively small or restricted compared to traditional airport runways (e.g., vertical takeoff and landing airports, parking areas, or driveways). These usage requirements may impose design constraints on aircraft size, weight, and operational efficiency (e.g., drag, energy use), which may affect the design and configuration of aircraft components.

[0006] The disclosed embodiments provide new and improved configurations for aircraft components not observed in conventional aircraft, and / or identify design standards for components that differ from those in conventional aircraft. This combination of alternative configurations and design standards addresses the shortcomings and challenges of conventional components, resulting in the various configurations and designs disclosed herein for components of aircraft powered by electric propulsion systems. The disclosed embodiments can also provide improvements for hybrid-electric aircraft, such as aircraft incorporating battery packs and / or fuel cells like hydrogen fuel cells, or gas-electric hybrid-electric aircraft.

[0007] In some embodiments, the electric propulsion system-driven aircraft of this disclosure can be designed to perform both vertical takeoff and landing, as well as conventional takeoff and landing, wherein the distributed electric propulsion system enables vertical flight, horizontal and lateral flight, and transitions. Thrust can be generated by supplying high-voltage electrical power to multiple electric engines of the distributed electric propulsion system, which may include the necessary components to convert the high-voltage electrical power into mechanical shaft power to rotate the propeller. The embodiments disclosed herein may relate to optimizing the energy density of the electric propulsion system. Embodiments may include electric engines connected to an onboard electric power source, which may include devices capable of storing energy, such as batteries or capacitors, and may include one or more systems for utilizing or generating electricity, such as fuel-powered generators or solar panel arrays. Some of the disclosed embodiments reduce the weight and space of components in the aircraft, thereby improving aircraft efficiency and performance. The disclosed embodiments also improve passenger transport safety in failure scenarios by using new and improved safety protocols and system redundancy to minimize any single point of failure in the aircraft propulsion system. Some of the disclosed embodiments also provide new and improved methods to meet and exceed aviation and transportation laws and regulations. For example, the U.S. Federal Aviation Administration enforces federal laws and regulations that require safety components, such as fire barriers, to be located near engines using oil or other flammable materials in amounts exceeding thresholds. Fire barriers may include engine components or aircraft components designed, constructed, or installed primarily to prevent any hazardous amounts of air, fluid, or flame from bypassing or passing through the fire barrier and / or to prevent corrosion. In some embodiments, fire barriers may include components separate from additional components as described herein. In some embodiments, fire barriers may include firewalls, fire barriers, fire-resistant barriers, flame-retardant barriers, or any other barriers that ensure any hazardous amounts of air, fluid, or flame cannot bypass or pass through the barrier and / or prevent corrosion. For example, while an airframe may be constructed to prevent any hazardous amounts of air, fluid, or flame from bypassing or passing through a fire barrier and / or to prevent corrosion, the airframe may not be considered a fire barrier because its primary purpose is not to serve as a fire barrier. In some embodiments, electric propulsion systems use oil below a threshold level to provide efficient and effective lubrication and cooling, resulting in aircraft that do not require engine fire barriers, thereby reducing aircraft weight while maximizing performance and efficiency.

[0008] In some embodiments, the distributed electric propulsion system may comprise twelve electric engines, which may be mounted on booms at the front and rear of the aircraft's main wings. Subgroups of electric engines, such as those mounted at the front of the main wings, may be tiltable in flight between a horizontally oriented position (e.g., to generate forward thrust for cruise) and a vertically oriented position (e.g., to generate vertical lift for takeoff, landing, and hovering). The propeller of the front electric engine may rotate clockwise or counterclockwise. The propeller may rotate in the opposite direction relative to adjacent propellers. The rear electric engine may be fixed in a vertically oriented position (e.g., to generate vertical lift). The propeller associated with the rear electric engine may also rotate clockwise or counterclockwise. In some embodiments, the difference in rotation direction may be achieved using the direction of engine rotation. In other embodiments, all engines may rotate in the same direction, and different propeller rotation directions may be achieved using gear mechanisms.

[0009] In some embodiments, the aircraft may have a number of electric engines in various combinations of front and rear engine configurations. For example, the aircraft may have six front electric engines and six rear electric engines, four front electric engines and four rear electric engines, or any other combination of front and rear engines, including embodiments in which the number of front and rear electric engines is not equal.

[0010] In some embodiments, for vertical takeoff and landing (VTOL) missions, the front electric engine and the rear electric engine can provide vertical thrust during takeoff and landing. During the forward flight phase, the front electric engine can provide horizontal thrust, while the propeller of the rear electric engine can retract to a fixed position to minimize drag. The rear electric engine can be actively retracted using position monitoring. The transition from vertical to horizontal flight and vice versa can be achieved via a tilting propeller subsystem. The tilting propeller subsystem can redirect thrust between the primary vertical direction during vertical flight mode and the horizontal or near-horizontal direction during the forward flight cruise phase. A variable pitch mechanism can change the blade collective angle of the front electric engine's propeller hub assembly for operation during hovering, transition, and cruise phases.

[0011] In some embodiments, during conventional takeoff and landing (CTOL) missions, the forward electric engine can provide horizontal thrust for wing-borne takeoff, cruise, and landing, and the wing can provide vertical lift. In some embodiments, the tail electric engine may not be used to generate thrust during CTOL missions, and the tail propeller may be retracted in place. In other embodiments, the tail electric engine may be used at reduced power to shorten the length of CTOL takeoff or landing.

[0012] The disclosed embodiments provide a rotor assembly including a sleeve, a rotor hub, and a plurality of tapered magnets circumferentially disposed around the inner diameter of the sleeve. The plurality of tapered magnets are configured to abut against each other and include a first set of tapered magnets and a second set of tapered magnets. Axial insertion of the first set of tapered magnets relative to the second set of tapered magnets is configured to increase the diameter of the sleeve. The rotor hub is configured to hold at least one of the plurality of tapered magnets or the sleeve.

[0013] The sleeve can be configured to hold the plurality of tapered magnets. The sleeve may include carbon fiber.

[0014] The rotor assembly may include a core. The core may include at least one notch, for example, for engaging with the rotor hub. The rotor assembly may include a first rotor hub abutting against a first side of the stacked core and a second rotor hub abutting against a second side of the core opposite to the first side. The rotor assembly may include at least one cavity disposed between the plurality of conical magnets and the core, wherein the at least one cavity is configured to guide fluid for cooling the magnets in the plurality of conical magnets. The core or the at least one cavity may be configured to deliver the fluid for directly cooling the plurality of conical magnets.

[0015] The disclosed embodiments also provide an electric propulsion system for a vertical takeoff and landing (VTOL) aircraft. The electric propulsion system includes at least one electric engine directly or indirectly mechanically connected to the fuselage of the VTOL aircraft. The electric engine includes a gearbox assembly. The gearbox assembly includes a sun gear and an electric motor having a stator and the rotor assembly. The rotor assembly includes a sleeve, a rotor hub, and a plurality of conical magnets circumferentially disposed around the inner diameter of the sleeve. The plurality of conical magnets are configured to abut against each other and include a first set of conical magnets and a second set of conical magnets. The axial insertion of the first set of conical magnets relative to the second set of conical magnets is configured to increase the diameter of the sleeve. The rotor hub is configured to hold at least one of the plurality of conical magnets or the sleeve.

[0016] The sun gear can be attached to the rotor hub. The gearbox may include a bearing, wherein the outer diameter of the bearing contacts the inner diameter of the sun gear.

[0017] The sleeve can be configured to hold the plurality of conical magnets. The sleeve may comprise carbon fiber.

[0018] The rotor assembly may include a core. The core may include at least one notch, for example, for engaging with the rotor hub. The rotor assembly may include a first rotor hub abutting against a first side of the core and a second rotor hub abutting against a second side of the core opposite to the first side. The rotor assembly may include at least one cavity disposed between the plurality of tapered magnets and the core, wherein the at least one cavity is configured to guide fluid for cooling the magnets among the plurality of tapered magnets. The core or the at least one cavity may be configured to deliver the fluid for directly cooling the plurality of magnets.

[0019] The disclosed embodiments also provide a vertical takeoff and landing (VTOL) aircraft that includes an electric propulsion system.

[0020] The disclosed embodiments further provide a method for assembling a rotor assembly. The method includes inserting a plurality of first conical magnets and a plurality of second conical magnets into each other from opposite axial directions, such that each of the plurality of second conical magnets is located between adjacent pairs of first conical magnets. The plurality of first conical magnets and the plurality of second conical magnets are arranged to form a magnet ring abutting against the inner surface of a stretchable sleeve.

[0021] Inserting the plurality of first conical magnets and the plurality of second conical magnets may include increasing the diameter of the stretchable sleeve. The method may include inserting a bearing into a sun gear and attaching the sun gear to the at least one rotor hub. The method may include balancing the rotor assembly. The at least one rotor hub may hold at least one of the magnet rings or the stretchable sleeve.

[0022] The disclosed embodiments also provide a method for manufacturing a rotor assembly of an electric motor. The method includes loading a plurality of first magnets into a magnet insertion tool; loading a plurality of second magnets into the magnet insertion tool, wherein the plurality of first magnets and the plurality of second magnets are shaped to form a magnet ring of the rotor assembly; and loading a sleeve into the magnet insertion tool; the method further includes: performing a first insertion movement using the magnet insertion tool, wherein the first insertion movement includes moving one of the plurality of first magnets or the plurality of second magnets in a radial direction of the sleeve; performing a second insertion movement using the magnet insertion tool, wherein the second insertion movement includes moving one of the plurality of first magnets or the plurality of second magnets relative to the sleeve in an axial direction of the sleeve; and during one of the first insertion movement or the second insertion movement, expanding the radius of the sleeve in the radial direction using the magnet insertion tool.

[0023] The method may include simultaneously performing at least a portion of the first insertion movement and the second insertion movement. During the second insertion movement, one of the plurality of first magnets or the plurality of second magnets may remain stationary relative to the sleeve in the axial direction. The method may include moving both the plurality of first magnets and the plurality of second magnets in the radial direction during the first insertion movement.

[0024] The first insertion movement may involve expanding the sleeve by pressing the plurality of first magnets against the sleeve in the radial direction. The second insertion movement may involve sliding the plurality of second magnets in the axial direction to align them with both the plurality of first magnets and the sleeve. Expanding the radius of the sleeve may include expanding the radius from a first radius to a second radius. The method may include contracting the radius of the sleeve from the second radius to a third radius. In some embodiments, the third radius is greater than the first radius and less than the second radius. The third radius may be at least 98% of the second radius.

[0025] The plurality of first magnets and the plurality of second magnets may be tapered along the axial direction.

[0026] The plurality of first magnets may be supported on a plurality of first magnet wedges of the magnet insertion tool. The plurality of second magnets may be supported on a plurality of second magnet wedges of the magnet insertion tool. The method may include, during the first insertion movement, moving the plurality of first magnets, the plurality of first magnet wedges, the plurality of second magnets, and the plurality of second magnet wedges in the radial direction using an expansion mandrel of the magnet insertion tool.

[0027] The expansion mandrel may include a plurality of first push rods configured to push the plurality of first magnetic wedges and a plurality of second push rods configured to push the plurality of second magnetic wedges. The method may include sliding the plurality of first magnetic wedges relative to the surfaces of the plurality of first push rods using the magnetic insertion tool. The method may also include sliding the plurality of second magnetic wedges relative to the surfaces of the plurality of second push rods using the magnetic insertion tool.

[0028] The expansion mandrel may include a push rod guide plate configured to guide the plurality of first push rods and the plurality of second push rods in the radial direction. The expansion mandrel may include an alignment shaft configured to align the push rod guide plate in the axial direction when the push rod guide plate guides the plurality of first push rods and the plurality of second push rods in the radial direction.

[0029] The magnet insertion tool may include a first support plate configured to support the plurality of first magnet wedges and a second support plate configured to support the plurality of second magnet wedges. The method may include moving the plurality of first magnet wedges relative to the first support plate in the radial direction; and moving the plurality of second magnet wedges relative to the second support plate in the radial direction.

[0030] The method may include pressing the second support plate against the first support plate in the axial direction during the first insertion movement and the second insertion movement.

[0031] The method may include: moving the plurality of first magnetic wedges relative to the first support plate in the radial direction by moving the plurality of first magnetic wedges in a plurality of first slots in the first support plate; or moving the plurality of second magnetic wedges relative to the second support plate in the radial direction by moving the plurality of second magnetic wedges in a plurality of second slots in the second support plate. Attached Figure Description

[0032] Figure 1 This is an illustration of a perspective view of an exemplary VTOL aircraft consistent with the disclosed embodiments.

[0033] Figure 2 This is another illustration of an exemplary VTOL aircraft in an alternative configuration, consistent with embodiments of this disclosure.

[0034] Figure 3 This is an illustration of the top plan view of an exemplary VTOL aircraft consistent with embodiments of this disclosure.

[0035] Figure 4 This is a schematic diagram illustrating the rotation of an exemplary propeller of a VTOL aircraft consistent with the disclosed embodiments.

[0036] Figure 5 This is a schematic diagram illustrating an exemplary power connection in a VTOL aircraft consistent with the disclosed embodiments.

[0037] Figure 6 This is a block diagram illustrating an exemplary architecture and design of the electric propulsion unit of a VTOL aircraft consistent with the disclosed embodiments.

[0038] Figure 7 This is a schematic diagram illustrating an exemplary tilting electric propulsion system for a VTOL aircraft consistent with the disclosed embodiments.

[0039] Figures 8A-8C This is an illustration of an exemplary tilt-electric propulsion system for a VTOL aircraft consistent with the disclosed embodiments.

[0040] Figure 9 This is a schematic diagram illustrating an exemplary lift-electric propulsion system for a VTOL aircraft consistent with the disclosed embodiments.

[0041] Figures 10A-10B This is an illustration of an exemplary lift-electric propulsion system for a VTOL aircraft consistent with the disclosed embodiments.

[0042] Figure 11 This is an illustration of a rotor assembly consistent with the disclosed embodiments.

[0043] Figures 12A-12B This is an illustration of an isometric view of a rotor assembly consistent with the disclosed embodiments.

[0044] Figures 13A-13B This is an illustration of a side view of a rotor assembly consistent with the disclosed embodiments.

[0045] Figure 14A This is an illustration of a front view of a rotor assembly consistent with the disclosed embodiments.

[0046] Figure 14B This is an illustration of a partial front cross-sectional view of a magnet assembly consistent with the disclosed embodiments.

[0047] Figure 15 This is an illustration of a top view of a stacked core consistent with the disclosed embodiments.

[0048] Figure 16 This is an illustration of a rotor hub consistent with the disclosed embodiment.

[0049] Figures 17A-17D It is an illustration of a cross-sectional view of a rotor assembly consistent with the disclosed embodiments.

[0050] Figures 18A-18F This is a diagram illustrating the assembly process of a rotor assembly consistent with the disclosed embodiments.

[0051] Figure 19 This is an illustration of an exploded view of a rotor assembly consistent with the disclosed embodiments.

[0052] Figure 20 It is an illustration of a cross-sectional view of a rotor assembly consistent with the disclosed embodiments.

[0053] Figures 21A-21B It is an illustration of a cross-sectional view of a rotor assembly consistent with the disclosed embodiments.

[0054] Figure 22 It is an illustration of a cross-sectional view of a rotor assembly consistent with the disclosed embodiments.

[0055] Figures 23A-23BThis is an illustration of a front view of a rotor assembly consistent with the disclosed embodiments.

[0056] Figures 24A-24G Example mandrels and mandrel components for manufacturing rotor assemblies are shown, consistent with embodiments of this disclosure.

[0057] Figures 25A-25F A first view shows an example method for manufacturing a rotor assembly consistent with embodiments of this disclosure.

[0058] Figures 26A-26B An example wedge of a magnet insertion tool consistent with embodiments of this disclosure is shown.

[0059] Figures 27A-27G A second view shows an example method for manufacturing a rotor assembly consistent with embodiments of this disclosure.

[0060] Figures 28A-28B A cross-sectional view of an example magnet insertion tool consistent with embodiments of the present disclosure is shown.

[0061] Figure 29 A view of a magnet insertion tool consistent with an embodiment of this disclosure is shown.

[0062] Figure 30 A view of a magnet insertion tool consistent with an embodiment of this disclosure is shown.

[0063] Figure 31 An example method for manufacturing a rotor assembly consistent with embodiments of this disclosure is shown. Detailed Implementation

[0064] The disclosed embodiments provide systems, subsystems, and components for rotor assemblies, as well as methods for assembling or manufacturing said systems, subsystems, and components.

[0065] The disclosed embodiments provide systems, subsystems, and components for novel VTOL aircraft, which have various combinations of electric propulsion and cooling systems that maximize performance while minimizing weight.

[0066] In some embodiments, the electric propulsion system described herein can generate thrust by supplying high-voltage (HV) electrical power to an electric engine, which in turn converts the HV electrical power into mechanical shaft power for rotating the propeller. The aircraft described herein may include multiple electric engines mounted at the front and rear of the wings. The engines may be mounted directly to the wings or to one or more booms attached to the wings. The amount of thrust generated by each electric engine can be controlled by torque commands provided to each electric engine by the flight control system (FCS) via a digital communication interface. Embodiments may include a front electric engine capable of changing its orientation or tilt. Some embodiments include a front engine that may have a clockwise (CW) or counterclockwise (CCW) rotation direction. The front electric propulsion subsystem may consist of a multi-bladed adjustable-pitch propeller and a variable-pitch subsystem.

[0067] In some embodiments, the aircraft may include a tail-mounted electric motor or elevator, which may be of the clockwise (CW) or counterclockwise (CCW) type. Some embodiments may include a tail-mounted electric motor utilizing a multi-bladed fixed-pitch propeller.

[0068] As described herein, the orientation and use of electric propulsion system components can be varied throughout the operation of the aircraft. In some embodiments, during vertical takeoff and landing, both the forward and tail propulsion systems can provide vertical thrust. During the forward flight phase, the forward propulsion system can provide horizontal thrust, while the tail propulsion system's propeller can be retracted to a fixed position to minimize drag. The tail electric propulsion system can be actively retracted using position monitoring. Some embodiments may include a transition from vertical to horizontal flight and vice versa. In some embodiments, the transition can be achieved via a tilting propeller system (TPS). The TPS redirects the electric propulsion system between the primary vertical direction during vertical flight mode and the primary horizontal direction during forward flight mode. Some embodiments may include a variable pitch mechanism that can change the total angle of the forward propulsion system propeller blades for operation during hovering, cruise, and transition phases. Some embodiments may include a conventional takeoff and landing (CTOL) configuration, such that the tilting propeller provides horizontal thrust for wing-borne takeoff, cruise, and landing phases. In some embodiments, the tail electric motor is not used to generate thrust during CTOL missions and the tail propeller is retracted in a position that minimizes drag.

[0069] In some embodiments, the electric engine as described herein may have design features to mitigate and prevent non-containment fires, such as utilizing non-hazardous amounts of flammable fluid contained in both the tilting engine and the lift engine. For example, in some embodiments, the electric engine may be configured to utilize less than one quart of oil or another flammable fluid. Some embodiments may include an electric engine containing a non-hazardous amount of air such that any fire cannot sustain a duration sufficient to migrate to another part of the aircraft. In some embodiments, the non-hazardous amount of air may be in contact with the flammable liquid throughout the electric engine. Some examples may include an electric engine containing up to one, two, three, four, five, ten, or twenty liters of air within the electric engine housing. In some embodiments, the amount of air present within the electric engine housing may be in a fixed ratio to the amount of oil or other liquid used for cooling within the electric propulsion system. Such a ratio can be driven by determining sufficient thermal mass required to properly cool the electric propulsion system. Some embodiments may include an air-to-oil ratio of approximately 3:1 within the electric propulsion system. Some embodiments may include an electric engine housing in which 75% of the open volume (i.e., the internal volume not occupied by components of the electric engine) is composed of air, and 25% of the open volume is composed of oil or some other liquid used for cooling and / or lubrication. Some embodiments may also be configured to have no nominal ignition source within the electric engine, possess an engine overheating operating limit that is at least 50°C lower than the auto-ignition temperature of the flammable fluid, and include overheat detection and protection, overvoltage detection and protection, and / or overcurrent detection and protection. Furthermore, some embodiments may include an electric propulsion system in which the overall temperature of the electric propulsion system is below the auto-ignition temperature and flash point of the oil or other liquid present within the electric propulsion system under all normal operating conditions. In some embodiments, abnormal conditions that raise the overall temperature of the electric propulsion system may result in a system response that prevents the oil or other liquid from exceeding its flash point and auto-ignition temperature. In some embodiments, the air-to-oil or other liquid ratio may ensure that, in the event of a fire within the electric engine housing, including if a fire is caused by an electric arc, the amount of air present within the electric engine housing will not allow the fire to spread to other areas of the aircraft. In some embodiments, these and other design features may produce an electric motor that is considered to be outside a designated fire zone by one or more guidelines or regulations.

[0070] The exemplary embodiments will now be described in detail with reference to the accompanying drawings, which illustrate examples of the described embodiments. The following description refers to the accompanying drawings, in which, unless otherwise stated, the same numerals in different figures denote the same or similar elements. In some aspects of the drawings, elements may have the same numerals and refer to similar elements of the disclosed embodiments. The embodiments set forth in the following description of the exemplary embodiments do not represent all embodiments consistent with this disclosure. Instead, they are merely examples of apparatuses and methods consistent with aspects of the subject matter recounted in the appended claims.

[0071] A. Exemplary features of electric aircraft

[0072] Figure 1 This is an illustration of a perspective view of an exemplary VTOL aircraft consistent with the disclosed embodiments. Figure 2 This is another illustration of an exemplary VTOL aircraft in an alternative configuration, consistent with embodiments of this disclosure. Figure 1 and Figure 2 VTOL aircraft 100 and 200, consistent with embodiments of this disclosure, are shown in cruise configuration and vertical takeoff, landing, and hovering configurations (also referred to herein as “takeoff and landing” configurations). Figure 1 The components corresponding to those in Figure 2 may have similar reference numerals and refer to similar components of aircraft 100, 200. Aircraft 100, 200 may include fuselages 102, 202, wings 104, 204 mounted to fuselages 102, 202, and one or more rear stabilizers 106, 206 mounted to the rear of fuselages 102, 202. Multiple lift propellers 112, 212 may be mounted to wings 104, 204 and may be configured to provide lift for vertical takeoff, landing, and hovering. Multiple tilt propellers 114, 214 may be mounted to wings 104, 204 and may tilt between a lift configuration and a cruise configuration, in which the multiple tilt propellers provide a portion of the lift required for vertical takeoff, landing, and hovering, such as... Figure 2 As shown, in the cruise configuration, the plurality of tilting propellers provide forward thrust to the aircraft 100 for horizontal flight, such as Figure 1 As shown. As used herein, a tilt propeller lift configuration refers to any tilt propeller orientation in which tilt propeller thrust primarily provides lift to the aircraft, while a tilt propeller cruise configuration refers to any tilt propeller orientation in which tilt propeller thrust primarily provides forward thrust to the aircraft.

[0073] In some embodiments, lift propellers 112, 212 can be configured to provide lift only, with all horizontal thrust provided by the tilting propellers. Therefore, lift propellers 112, 212 can be configured to have a fixed position and generate thrust only during takeoff, landing, and hovering phases of flight. Simultaneously, tilting propellers 114, 214 can be tilted upwards into a lift configuration in which thrust from propellers 114, 214 is directed downwards to provide additional lift.

[0074] For forward flight, tilting propellers 114 and 214 can tilt from their lift configuration to their cruise configuration. In other words, the orientation of tilting propellers 114 and 214 can change from an orientation where tilting propeller thrust is directed downwards (to provide lift during vertical takeoff, landing, and hovering) to an orientation where tilting propeller thrust is directed backwards (to provide forward thrust to aircraft 100 and 200). The tilting propeller assembly for a specific electric engine can tilt about an axis of rotation defined by the mounting point connecting the boom and the electric engine. When aircraft 100 and 200 are in fully forward flight, lift can be provided entirely by wings 104 and 204. Meanwhile, in cruise configuration, lift propellers 112 and 212 can be shut off. The blades 120 and 220 of lift propellers 112 and 212 can be maintained in a low-drag position for aircraft cruise. In some embodiments, the lift propellers 112 and 212 may each have two blades 120 and 220, respectively, which can be locked for cruising in a minimum drag position, in which one blade is directly in front of the other blade, such as... Figure 1 As shown. In some embodiments, the lift propellers 112, 212 have more than two blades. In some embodiments, the tilting propellers 114, 214 may contain more blades 116, 216 than the lift propellers 112, 212. For example, as Figure 1 and Figure 2 As shown, lift propellers 112 and 212 may each contain, for example, two blades, while tilt propellers 114 and 214 may each contain more blades, such as the five blades shown. In some embodiments, each of tilt propellers 114 and 214 may have two to five blades, and possibly more, depending on the aircraft's design considerations and requirements.

[0075] In some embodiments, the aircraft may include a single wing 104, 204 on each side of the fuselage 102, 202 (or a single wing extending across the entire aircraft). At least a portion of the lift propellers 112, 212 may be located at the rear of the wings 104, 204, and at least a portion of the jib propellers 114, 214 may be located at the front of the wings 104, 204. In some embodiments, all of the lift propellers 112, 212 may be located at the rear of the wings 104, 204, and all of the jib propellers 114, 214 may be located at the front of the wings 104, 204. According to some embodiments, all the lift propellers 112, 212 and the jib propellers 114, 214 may be mounted to the wings—that is, no lift propeller or jib propeller may be mounted to the fuselage. In some embodiments, the lift propellers 112 and 212 may all be located at the rear of the wings 104 and 204, and the tilt propellers 114 and 214 may all be located at the front of the wings 104 and 204. According to some embodiments, all lift propellers 112 and 212 and tilt propellers 114 and 214 may be positioned inside the ends of the wings 104 and 204.

[0076] In some embodiments, the lift propellers 112, 212 and the tilt propellers 114, 214 can be mounted to the wings 104, 204 via booms 122, 222. Booms 122, 222 can be mounted below the wings 104, 204, on the top of the wings, and / or integrated into the wing profile. In some embodiments, the lift propellers 112, 212 and the tilt propellers 114, 214 can be directly mounted to the wings 104, 204. In some embodiments, each boom 122, 222 can mount one lift propeller 112, 212 and one tilt propeller 114, 214. The lift propellers 112, 212 can be mounted at the rear end of the booms 122, 222, and the tilt propellers 114, 214 can be mounted at the front end of the booms 122, 222. In some embodiments, the lift propellers 112, 212 can be mounted in fixed positions on the booms 122, 222. In some embodiments, the tilt propellers 114, 214 may be hinged to the front end of booms 122, 222. The tilt propellers 114, 214 may be mounted to booms 122, 222 such that, in their cruise configuration, the tilt propellers 114, 214 are aligned with the body of booms 122, 222, thereby forming a continuous extension at the front end of booms 122, 222 that minimizes drag during forward flight.

[0077] In some embodiments, aircraft 100, 200 may include, for example, a wing on each side of fuselage 102, 202 or a single wing extending across the aircraft. According to some embodiments, at least one wing 104, 204 is a high wing mounted to the upper side of fuselage 102, 202. According to some embodiments, the wing includes control surfaces such as flap doors and / or ailerons. According to some embodiments, wings 104, 204 may have been designed with profiles to reduce drag during forward flight. In some embodiments, the wingtip profile may be curved and / or tapered to minimize drag.

[0078] In some embodiments, the rear stabilizers 106, 206 include control surfaces, such as one or more rudders, one or more elevators, and / or one or more combinations of rudder-elevator. The wing can have any suitable design. In some embodiments, the wing has a tapered leading edge.

[0079] In some embodiments, the lift propellers 112, 212 or the yaw propellers 114, 214 may be deflected relative to at least one other lift propeller 112, 212 or yaw propeller 114, 214. As used herein, deflection refers to the relative orientation of the axis of rotation of the lift propeller / yaw propeller about a line parallel to the forward-reverse direction, analogous to the roll degree of freedom of an aircraft. Deflection of the lift propeller and / or yaw propeller can help minimize damage from a propeller burst by orienting the plane of rotation of the lift propeller / yaw propeller disk (blades plus the hub on which the blades are mounted) so as not to intersect with critical parts of the aircraft (such areas in which personnel may be positioned, critical flight control systems, batteries, adjacent propellers, etc.) or other propeller disks, and can provide enhanced yaw control during flight.

[0080] Figure 3 This is an illustration of a top plan view of an exemplary VTOL aircraft consistent with embodiments of this disclosure. The aircraft 300 shown in the figure may be, respectively, in... Figure 1 and Figure 2The diagram shows a top plan view of aircraft 100 and 200. As discussed herein, aircraft 300 may include twelve electric propulsion systems distributed across aircraft 300. In some embodiments, the distribution of electric propulsion systems may include six forward electric propulsion systems 314 and six tail electric propulsion systems 312 mounted on booms at the forward and aft ends of the main wing 304 of aircraft 300. In some embodiments, the rear end length of boom 324 from wing 304 to lift propeller 312 may include similar rear end lengths of boom 324 across multiple rear ends of boom 324. In some embodiments, the length of the rear ends of boom 324 may vary across six exemplary rear ends of boom 324. For example, each rear end of boom 324 may include different lengths from wing 304 to lift propeller 312, or subgroups of the rear ends of boom 324 may be similar in length. In some embodiments, the front end of boom 322 may include various lengths from wing 304 to tilting propeller 314 across the front end of boom 322. For example, as... Figure 3 As shown, the length of the boom 322 from the tip of the tiltrotor 314 closest to the fuselage to the tip of the wing 304 may be greater than the length of the boom 322 from the wing 304 to the tip of the tiltrotor 314 furthest from the fuselage. Some embodiments may include six exemplary boom tips with similar lengths across the boom, or any other length distribution of the boom from the wing 304 to the tip of the tiltrotor 314. Some embodiments may include an aircraft 300 equipped with eight electric propulsion systems, wherein the eight electric propulsion systems have four forward electric propulsion systems 314 and four tail electric propulsion systems 312, or any other distribution of forward and tail electric propulsion systems, including embodiments in which the number of forward electric propulsion systems 314 is less than or greater than the number of tail electric propulsion systems 312. Additionally, Figure 3 An exemplary embodiment of a VTOL aircraft 300 is depicted, having a front propeller 314 in a horizontal orientation for horizontal flight and a tail propeller blade 320 in a retracted position for forward flight.

[0081] As disclosed herein, the front electric propulsion system and the rear electric propulsion system can be of clockwise (CW) or counterclockwise (CCW) type. Some embodiments may include various front electric propulsion systems that combine both CW and CCW types. In some embodiments, the rear electric propulsion system may incorporate a combination of CW and CCW type systems.

[0082] Figure 4 This is a schematic diagram illustrating exemplary propeller rotation of a VTOL aircraft consistent with the disclosed embodiments. The aircraft 400 shown in the figure may be as described in Figures 1, 2, and 3 respectively. Figure 3The diagram shows top plan views of aircraft 100, 200, and 300. Aircraft 400 may include six forward electric propulsion systems, three of which have a CW type 424, and the remaining three have a CCW type. In some embodiments, three tail electric propulsion systems may have a CCW type 428, while the remaining three tail electric propulsion systems may have a CW type 430. Some embodiments may include an aircraft 400 with four forward electric propulsion systems and four tail electric propulsion systems, each having two CW types and two CCW types. In some embodiments, the propellers may rotate in opposite directions relative to adjacent propellers to eliminate torque steer experienced by the aircraft's fuselage or wings due to propeller rotation. In some embodiments, the difference in rotation direction may be achieved using the direction of engine rotation. In other embodiments, all engines may rotate in the same direction, and different propeller rotation directions may be achieved using gear mechanisms.

[0083] Some embodiments may include an aircraft 400 having a front electric propulsion system and a rear electric propulsion system, wherein the amount of CW type 424 and CCW type 426 is not equal in the front electric propulsion system, in the rear electric propulsion system, or in both the front and rear electric propulsion systems.

[0084] Figure 5This is a schematic diagram illustrating exemplary power connections in a VTOL aircraft consistent with the disclosed embodiments. VTOL aircraft may have various power systems connected to diagonally opposite electric propulsion systems. In some embodiments, the power systems may include high-voltage power systems. Some embodiments may include high-voltage power systems connected to the electric engines via high-voltage channels. In some embodiments, aircraft 500 may include six power systems comprising batteries 526, 528, 530, 532, 534, and 536 stored within the wings 570 of aircraft 500. In some embodiments, aircraft 500 may include six forward electric propulsion systems having six electric engines 502, 504, 506, 508, 510, and 512, and six tail electric propulsion systems having six electric engines 514, 516, 518, 520, 522, and 524. In some embodiments, batteries may be connected to diagonally opposite electric engines. In this configuration, the first power system 526 can supply power to the electric engine 502 via power connection channel 538 and to the electric engine 524 via power connection channel 540. In some embodiments, the first power system 526 can also be paired with a fourth power system 532 via power connection channel 542, which has a fuse to prevent excessive current from flowing through the power systems 526 and 532. Further, with respect to this embodiment, the VTOL aircraft 500 may include a second power system 528 paired with a fifth power system 534 via a power connection channel 548 with a fuse, and can supply power to the electric engines 510 and 516 via power connection channels 544 and 546, respectively. In some embodiments, a third power system 530 can be paired with a sixth power system 536 via a power connection channel 554 with a fuse, and can supply power to the electric engines 506 and 520 via power connection channels 550 and 552, respectively. The fourth power system 532 can also supply power to electric motors 508 and 518 via power connection channels 556 and 558, respectively. The fifth power system 534 can also supply power to electric motors 504 and 522 via power connection channels 560 and 562, respectively. The sixth power system 536 can also supply power to electric motors 512 and 514 via power connection channels 564 and 566, respectively.

[0085] As disclosed herein, an electric propulsion system may include an electric engine connected via a high-voltage channel or power connection channel to a high-voltage power system (e.g., a battery) located within the aircraft. Some embodiments may include various batteries stored within the aircraft wing, which has a high-voltage channel running through the aircraft (including the wing and boom) to the electric propulsion system. In some embodiments, multiple high-voltage power systems may be used to create an electric propulsion system with multiple high-voltage power sources to avoid the risk of single point of failure. In some embodiments, the aircraft may include multiple electric propulsion systems that may be patterned and wired to various batteries or power sources stored throughout the aircraft. It should be recognized that this configuration may be beneficial in avoiding the risk of single point of failure, where a failure of one battery or power source could cause a portion of the aircraft to lose the thrust required to continue flying or to perform a controlled landing. For example, if a VTOL has two forward electric propulsion systems and two aft propulsion systems, the forward and aft electric propulsion systems on opposite sides of the VTOL aircraft may be connected to the same high-voltage power system. In this configuration, if one high-voltage power system fails, the forward and rear electric propulsion systems on opposite sides of the VTOL aircraft will remain operational, providing a more balanced flight or landing compared to a forward and rear electric propulsion system failing on the same side of the VTOL aircraft. Some embodiments may include four forward electric propulsion systems and four rear electric propulsion systems, with diagonally opposite electric engines connected to a common battery or power source. Various configurations of electric engines electrically connected to the high-voltage power system may be included in some embodiments to avoid the risk of a single point of failure in the event of a power source failure, allowing the affected flight phase to continue, or the aircraft to perform an alternative flight phase in response to the failure.

[0086] As discussed above, an electric propulsion system may include an electric engine that provides mechanical shaft power to a propeller assembly to generate thrust. In some embodiments, the electric engine of the electric propulsion system may include a high-voltage power system that supplies high-voltage power to the electric engine and / or a low-voltage system that supplies low-voltage DC power to the electric engine. Some embodiments may include an electric engine that digitally communicates with a flight control system (“FCS”) including a flight control computer (“FCC”), which can send signals to and receive signals from the electric engine, the signals including command and response data or status. Some embodiments may include an electric engine capable of receiving and transmitting operating parameters from and to the FCC, these operating parameters including speed, voltage, current, torque, temperature, vibration, propeller position, and any other values ​​of operating parameters.

[0087] In some embodiments, the flight control system may include a system capable of communicating with the electric engine to send and receive analog / discrete signals to the electric engine and controlling devices capable of redirecting the thrust of the tilt propeller between the primary vertical direction during vertical flight mode and the primary horizontal direction during forward flight mode. In some embodiments, this system may be referred to as a tilt propeller system (“TPS”) and is capable of communicating and orienting additional features of the electric propulsion system.

[0088] Figure 6 A block diagram illustrating an exemplary architecture and design of the electric propulsion unit 600 consistent with the disclosed embodiments is shown. In some embodiments, the electric propulsion system 602 may include an electric engine subsystem 604 that supplies torque via an axial propeller subsystem 606 to generate thrust for the electric propulsion system 602. Some embodiments may include an electric engine subsystem 604 that receives low-voltage DC (LV DC) power from a low-voltage system (LVS) 608. Some embodiments may include an electric engine subsystem 604 that receives high-voltage (HV) power from a high-voltage power system (HVPS) 610, the high-voltage power system including at least one battery or another device capable of storing energy. In some embodiments, the high-voltage power system may include more than one battery or another device capable of storing energy that supplies high-voltage power to the electric engine subsystem 604. It should be appreciated that this configuration can be advantageous because it eliminates the risk of a single point of failure where a single battery failure could lead to a failure of the electric propulsion system 602.

[0089] Some embodiments may include an electric propulsion system 602 that includes an electric engine subsystem 604 that receives signals from and transmits signals to a flight control system 612. In some embodiments, the flight control system 612 may include a flight control computer capable of sending commands to and receiving status and data from the electric engine subsystem 604 using a Controller Area Network (“CAN”) data bus signal. It should be understood that while a CAN data bus signal is used between the flight control computer and the electric engine, some embodiments may include any form of communication capable of sending and receiving data from the flight control computer to and from the electric engine. In some embodiments, the flight control system 612 may also include a tilting propeller system (“TPS”) 614 capable of sending analog discrete data to and receiving analog discrete data from the tilting propeller’s electric engine subsystem 604. The tilt propeller system 614 may include a device capable of transmitting operating parameters to the electric engine subsystem 604 and articulating the orientation of the propeller subsystem 606 to redirect the thrust of the tilt propeller using mechanical components (such as gearbox assemblies, linear actuators, and any other configurations that change the orientation of the propeller subsystem 606) during various phases of flight.

[0090] As discussed throughout, exemplary VTOL aircraft may be equipped with various types of electric propulsion systems, including tilt propellers and lift propellers, the tilt propellers and lift propellers including a front electric engine with the ability to tilt during various phases of flight and a tail electric engine that remains in a direction and can only operate during certain phases of flight (i.e., takeoff, landing and hovering).

[0091] Figure 7 This is a schematic diagram illustrating an exemplary tiltable electric propulsion system for a VTOL aircraft consistent with the disclosed embodiments. The tiltable electric propulsion system 700 may include an electric engine assembly 702 aligned along an axis 724 connected to an output shaft 738 mechanically coupled to a propeller assembly 720, the propeller assembly including a hub, a rotator, and tilting propeller blades. In some embodiments, the electric engine assembly 702 may include a motor and gearbox assembly 704 aligned along and mechanically coupled to the axis 724. In some embodiments, the motor and gearbox assembly 704 may include an electric motor assembly including a stator 706 and a rotor 708. Figure 7As shown and present in some embodiments, stator 706 may include multiple stator windings connected to inverter 716. In this configuration, stator 706 may include one or more redundancies, such that in the event of a set of winding failures, power will still be delivered to stator 706 via one or more remaining windings, allowing electric motor assembly 702 to maintain power and continue to generate thrust at propeller assembly 720.

[0092] In some embodiments, the motor and gearbox assembly 704 may include a gearbox 710 aligned along a shaft 724 to provide gear reduction between the torque from the shaft 724 of the electric motor assembly, which includes a stator 706 and a rotor 708, and the output shaft 738. The torque applied to the output shaft 738 may be transmitted to the propeller assembly 720. Some embodiments may include a gearbox 710 containing an oil pump. In such embodiments, the oil pump may drive oil to circulate throughout the motor and gearbox assembly 704 at a speed equal to the rotation of the output shaft 738 to cool and lubricate the gearbox and electric motor components. In some embodiments, the oil pump may drive oil circulation at a speed greater than or less than the rotation of the output shaft 738. Some embodiments of the motor and gearbox assembly 704 may include a propeller position sensor 712 located within a housing, which can detect a magnetic field generated by the electric motor assembly to determine the propeller position. Other embodiments may include a propeller position sensor 712 powered by an inverter 716 and transmitting collected data to the inverter 716.

[0093] In some embodiments, the electric motor assembly 702 may further include an inverter assembly 714 aligned along axis 724. Inverter assembly 714 may include an inverter 716 and an inverter power source 740. Inverter power source 740 may accept low-voltage DC power from a low-voltage system 734 located outside the electric motor assembly 702. Inverter power source 740 may also accept low-voltage DC power originating from a high-voltage power system 732 located outside the electric motor assembly 702, which has already been converted to low-voltage DC power via a DC-DC converter 742. Inverter 716 may supply high-voltage AC power to the stator 706 of the electric motor assembly located within the motor and gearbox assembly 704 via at least one three-phase winding. Inverter assembly 714 may include inverter 716, which may receive flight control data from flight control computing subsystem 736.

[0094] In some embodiments, the motor and gearbox 704 may be located between the inverter assembly 714 and the propeller assembly 720. Some embodiments may also include a partition plate 744 coupled to the motor and gearbox assembly 704 and the inverter assembly 714. The partition plate 744 may create an enclosed environment for the upper portion of the motor and gearbox assembly 704 via a bell-shaped end cap assembly and for the lower portion of the inverter assembly 714 via a hot plate. In some embodiments, the partition plate 744 may serve as an integral mounting bracket for supporting a heat exchanger 718. The heat exchanger 718 may include, for example, folded fins or other types of heat exchangers. In some embodiments, the electric propulsion system 700 may circulate oil or other coolant throughout the electric motor assembly 702, the motor and gearbox assembly 704, or the inverter assembly 714 to transfer heat generated from the components to the oil or other coolant liquid. The heated oil or other coolant liquid may circulate through the heat exchanger 718 to transfer heat to an airflow 722 passing through the fins of the heat exchanger.

[0095] In some embodiments, the electric motor assembly 702 may be mounted or coupled to the boom structure 726 of the aircraft. A variable pitch mechanism 730 may be mechanically coupled to the propeller assembly 720. In some embodiments, the variable pitch mechanism may abut against the electric motor assembly 702. In some embodiments, the variable pitch mechanism 730 may be coupled to the variable pitch mechanism 730 such that it can be remotely mounted within the boom, wing, or fuselage of the aircraft. In some embodiments, the variable pitch mechanism 730 may be included within or adjacent to a shaft 724 that travels into the propeller assembly 720. The variable pitch mechanism 730 may be used to change the total angle of the propeller assembly blades of the forward electric motor as needed during hovering, transition, and cruise phases. Some embodiments may include an electric motor assembly 702 mechanically coupled to a yaw propeller subsystem 728, which may redirect thrust between the primary vertical direction during vertical flight mode and the primary horizontal direction during forward flight mode. In some embodiments, the yaw propeller subsystem may abut against the variable pitch mechanism 730. Some embodiments may include a tilting propeller subsystem 728, which includes various components located in various positions. For example, components of the tilting propeller subsystem may be coupled to the electric engine assembly 702, and other components may be coupled to the variable pitch mechanism 730. These various components of the tilting propeller subsystem 728 may work together to redirect the thrust of the tiltable electric propulsion system 700.

[0096] Figures 8A-8C This is an illustration of an exemplary tilt-electric propulsion system for a VTOL aircraft consistent with the disclosed embodiments. Figures 8A-8CSimilar reference numerals are used to denote similar elements in the tiltable electric propulsion systems 800A, 800B, and 800C. Therefore, similar design considerations and configurations can be considered throughout the embodiments.

[0097] Figure 8A and Figure 8B Side profiles and perspective views of tiltable electric propulsion systems 800A and 800B integrated into booms 812A and 812B in a cruise configuration, consistent with this disclosure, are shown respectively. The tiltable propeller electric propulsion systems 800A and 800B may include electric engine assemblies 802A and 802B housed within booms 812A and 812B of a VTOL aircraft. In some embodiments, the cruise configuration may include electric engine assemblies 802A and 802B housed within booms 812A and 812B. As described herein, electric engine assemblies 802A and 802B may include an electric motor assembly, a gearbox assembly, an inverter assembly having power connection channels 810A and 810B, and heat exchangers 804A and 804B. Electric engine assemblies 802A and 802B may be mechanically coupled to propulsion assemblies 808A and 808B, which include shaft flange assemblies 806A and 806B, a rotator, and propeller blades.

[0098] Figure 8C A top view along the rotator 808C of a tiltable electric propulsion system 800C integrated into the boom 812B in a lift configuration, consistent with this disclosure, is shown. Figure 8C As shown, the tiltable electric propulsion system 800C in a lift configuration may include electric engine assemblies 802A and 802B, which are mounted outside the boom 812C and change their orientation relative to the boom 812C.

[0099] As discussed in this article, a lift electric propulsion system can be configured to provide thrust in one direction and may not provide thrust during all phases of flight. For example, the lift system may provide thrust during takeoff, landing, and hovering, but may not provide thrust during cruise.

[0100] Figure 9This is a schematic diagram illustrating an exemplary lift-electric propulsion system for a VTOL aircraft consistent with the disclosed embodiments. The lift-electric propulsion system 900 may be mounted or coupled to a boom structure 924 of the aircraft. The lift-electric propulsion system 900 may include an electric engine assembly 902 aligned along an axis 940 connected to an output shaft 932 mechanically coupled to a propeller assembly 920, the propeller assembly including a hub and tilting propeller blades. In some embodiments, the electric engine assembly 902 may include a motor and gearbox assembly housing 904 aligned along and mechanically coupled to the axis 940. In some embodiments, the motor and gearbox assembly housing 904 may include an electric motor assembly including a stator 906 and a rotor 908. The stator 906 may include a plurality of stator windings connected to an inverter 916. In such a configuration, the stator 906 may include one or more redundancy and backup measures to avoid single points of failure in the event of failure. For example, stator 906 may include multiple windings such that if a winding fails, power can continue to be transmitted to stator 906 via the remaining windings, thereby allowing electric motor assembly 902 to maintain power and continue to generate thrust at propeller assembly 920.

[0101] In some embodiments, the motor and gearbox assembly housing 904 may include a gearbox 910 aligned along shaft 940 to provide gear reduction between the torque from shaft 932 of the electric motor assembly, including stator 906 and rotor 908, and output shaft 932. The torque applied to output shaft 932 may be transmitted to propeller assembly 920. Some embodiments may include gearbox 910 containing a fluid pump for circulating cooling and / or lubricating fluids. In the illustrated embodiment, the fluid pump is an oil pump. In such an embodiment, the oil pump may drive oil to circulate throughout the motor and gearbox assembly housing 904 at a speed equal to the rotation of output shaft 932 to cool and lubricate the gearbox and electric motor components. Some embodiments of the motor and gearbox assembly housing 904 may include a propeller position sensor 912 located within the housing, which can detect a magnetic field generated by the electric motor assembly to determine the propeller position. Another embodiment may include a propeller position sensor 912, which is powered by an inverter 916 and sends collected data to the inverter 916. The collected data may be transmitted to the flight control computing system 930 along with other flight control data.

[0102] In some embodiments, the electric motor assembly 902 may further include an inverter assembly housing 914 aligned along an axis shared with the axis of the output shaft 932. The inverter assembly housing 914 may include an inverter 916 and an inverter power source 934. The inverter power source 934 may accept low-voltage DC power from a low-voltage system 928 located outside the electric motor assembly 902. The inverter power source 934 may also accept low-voltage DC power from a high-voltage power system 926 located outside the electric motor assembly 902, which has been converted to low-voltage DC power via a DC-DC converter 936. The inverter 916 may supply high-voltage AC power to the stator 906 of the electric motor assembly located within the motor and gearbox assembly housing 904 via at least one three-phase winding. The inverter assembly 914 may include the inverter 916, which may transmit and receive data from the flight control computing subsystem 930.

[0103] In some embodiments, the motor and gearbox housing 904 may be located between the inverter assembly housing 914 and the propeller assembly 920. Some embodiments may also include a partition plate 938 coupled to both the motor and gearbox assembly housing 904 and the inverter assembly housing 914. The partition plate 938 may create an enclosed environment for the upper portion of the motor and gearbox assembly housing 904 via a bell-shaped end cap assembly and for the lower portion of the inverter assembly housing 914 via a hot plate. In some embodiments, the partition plate 938 may serve as an integral mounting bracket for supporting a heat exchanger 918. The heat exchanger 918 may include, for example, folded fins or other types of heat exchangers. In some embodiments, the electric propulsion system 900 may circulate oil or other coolant fluid throughout the electric motor assembly 902, the motor and gearbox assembly 904, or the inverter assembly 914 to transfer heat generated from the components to the oil or other coolant liquid. The heated oil or other coolant liquid may circulate through the heat exchanger 918 to transfer heat to an airflow 922 passing through the fins of the heat exchanger.

[0104] In some embodiments, tiltable electric propulsion systems and lift electric propulsion systems can have similar components. This can be advantageous for many design considerations present in VTOL aircraft. For example, from a manufacturability perspective, different types of electric propulsion systems with similar components can be beneficial in terms of manufacturing efficiency. Furthermore, having similar components can be beneficial in terms of risk management, as similar components have similar points of failure, and these points of failure can be well explored and designed when comparing systems with similar components to systems with different components and configurations.

[0105] While a tiltable electric propulsion system may have additional and, in some embodiments, different components compared to a lift electric propulsion system, it should be understood that in some embodiments, the tiltable electric propulsion system and the lift electric propulsion system may have the same component configuration. For example, in some embodiments, the tiltable electric propulsion system and the lift electric propulsion system may contain the same components, and the lift electric propulsion system may be coupled to the aircraft's boom, wing, or fuselage, making it unlikely to provide thrust in as many directions as the tiltable electric propulsion system.

[0106] Figures 10A-10B This is an illustration of an exemplary lift-electric propulsion system for a VTOL aircraft consistent with the disclosed embodiments. Figure 10A and Figure 10B Similar reference numerals are used to denote similar elements in the lift electric propulsion systems 1000A and 1000B. Therefore, similar design considerations and configurations can be considered throughout the embodiments.

[0107] Figure 10A A side profile of a lift electric propulsion system 1000A integrated into a boom 1010A in a lift configuration, consistent with this disclosure, is shown. The lift electric propulsion system 1000A may include an electric engine assembly 1002A housed within the boom 1010A of a VTOL aircraft. In some embodiments, the lift configuration may include the electric engine assembly 1002A vertically mounted within the boom 1010A. As described herein, the electric engine assembly 1002A may include an electric motor assembly, a gearbox assembly, an inverter assembly having a power connection channel 1008A, and a heat exchanger 1004A. The electric engine assembly 1002A may be mechanically coupled to a propulsion assembly 1006A, which includes a shaft flange assembly and propeller blades.

[0108] Figure 10B A top view of a lift electric propulsion system 1000B, integrated into a boom 1010B in a lift configuration, consistent with this disclosure, is shown.

[0109] Some embodiments of the disclosed electric motor may generate heat during operation and may include a thermal management system to ensure that components of the electric motor do not fail during operation. In some embodiments, a coolant may be used and circulated in various components of the motor (e.g., inverter, gearbox, or motor), through some components or through all components of the motor, to help manage the heat present in the motor. Some embodiments may include using air cooling methods to cool the electric motor, or using a mixture of coolant and air to manage the heat generated by the electric motor during operation. In some embodiments, the coolant used may also be the same liquid used as a lubricant throughout the inverter, gearbox, or motor. For example, components of the electric motor may be cooled using liquid or air, or a mixture of air and liquid cooling. As another example, air cooling may be used to cool the motor, while liquid cooling may be used to cool the inverter and gearbox. It should be understood that the cooling mixture may be used in any combination of electric motor components or within each component.

[0110] In some embodiments, oil can be used as a lubricant throughout the electric engine and also as a coolant fluid to help manage the heat generated by the engine during operation. Further for this example, different amounts of oil can be used as both lubricant and coolant fluid in the electric engine, with or without air cooling assistance, such as less than or equal to 1 quart, 1.5 quart, 2 quart, 2.5 quart, 3 quart, 5 quart, or any other amount required to lubricate and cool the electric engine. In some embodiments, the amount of cooling-related oil or fluid used in the system can be determined based on the amount of heat mass required for heat transfer of the components driving the electric propulsion system. As already disclosed herein, an electric engine can have different primary functions, such as being used only for lift and landing and therefore only in one orientation, or used during all phases of flight, such as lift, landing, and flight. An engine used in all phases of flight can experience various orientations throughout the flight and can include more lubricant and coolant than an engine used only in one orientation. Therefore, all engines on an aircraft may not contain the same amount of lubricant and coolant. For example, lift and landing engines may require less than a quart of oil, while engines operating in all phases of flight may require more than a quart. In some embodiments, the amount of oil or liquid used for cooling may be adequate to provide sufficient thermal mass to drive heat transfer to the components of the electric propulsion system, regardless of the orientation of the electric propulsion system. The embodiments discussed herein are exemplary and non-limiting, and do not specify limits to the amounts of lubricants and coolants that may be used in electric engines.

[0111] Some embodiments may use oil to lubricate and cool the electric motor. Such embodiments may require an additional volume of oil. In such embodiments, the additional oil may allow the removal of conventional components that can be used to cool the electric motor. For example, if the electric motor is cooled by another liquid, such as ethylene glycol, the engine may include separate heat exchangers for both the lubricant fluid and the coolant fluid. Therefore, in embodiments using a single fluid (e.g., oil) for lubrication and cooling, there will be an increase in oil, but only one heat exchanger will be needed. Thus, due to the use of fewer heat exchangers and potentially no other components, the overall system mass can be reduced, and a more satisfactory drag profile may be achieved. Furthermore, the efficiency of the system can be improved by using a single substance to lubricate and cool the engine, due to the reduction in mass and the benefits of cooling the engine with a substance rather than relying on air cooling, which may have problems traveling throughout the engine.

[0112] Some embodiments of electric motors may include various components for monitoring flammable fluids and for preventing flammable materials from entering certain sections of the electric motor. Some embodiments may include an electric motor with a wet zone housing, which may be defined by a gearbox, motor, and / or heat exchanger. In some embodiments, the electric motor may have up to 4 liters or more of air in contact with engine oil within the motor-gearbox housing. Embodiments of the motor-gearbox housing may use a ventilator to equalize internal and external pressure. Embodiments of the ventilator may include a ventilator protruding above a nearby design feature to prevent unintentional entry of external fluids. Some embodiments may include a ventilator with a screen and a detour entry path to prevent the entry of external debris. Embodiments may include observation windows present on both tilt-powered and lift-powered electric motors to check for overfilling or underfilling of oil during maintenance.

[0113] Some embodiments of the electric propulsion engine may include active protection features in both the front and rear electric propulsion engines, such as monitoring vibration and internal temperatures throughout the engine, including oil temperature, stator winding assembly temperature, inverter large-capacity capacitor temperature, power module temperature, control board power module temperature, control board control processor temperature, control board monitoring processor temperature, internal hot spot temperature, and various other operating conditions throughout the engine as needed. This monitoring can be accomplished using various sensors located throughout the electric propulsion system and the aircraft. Embodiments may include vibration limits based on known fault points or resonances in components, over-temperature limits based on known fault temperatures, and operating limits related to the auto-ignition temperature of fluids. In some embodiments, various sensors used to monitor operating conditions throughout the engine may report operating conditions to the flight control system. Some embodiments may include threshold operating values ​​that may be required before operating values ​​are sent to or flagged by the flight control system. In some embodiments, the flight control system may act in response to the detection of operating conditions to reduce the amount of power directed to the electric propulsion system. Some embodiments may include reducing the amount of power directed to the electric propulsion system to reduce mechanical wear or frictional sparks caused by vibration, and / or reducing power to lower the temperature of components present within the electric propulsion system. Furthermore, some embodiments may include reducing the power supplied to the electric propulsion system if the inverter's detected efficiency is less than a target efficiency. In some embodiments, such as when there are twelve electric propulsion systems within the aircraft, the flight control system may be used to reduce or terminate the power supplied to a single electric propulsion system while increasing the power directed to the remaining electric propulsion systems or a subset thereof to offset the reduction in lift generated by one electric propulsion system. In some embodiments, the flight control system may establish various thresholds for operating conditions corresponding to the reduction or increase in power supplied to the electric propulsion system.

[0114] Some embodiments may include a high-voltage power system with a fuse at the high-voltage battery terminal that can quickly and irreversibly disconnect the engine electrical connection to mitigate and prevent overcurrent events. This overcurrent protection can be activated when the electric motor's current consumption exceeds overcurrent operation. Therefore, in some embodiments, the fault condition leading to overcurrent may only result in transient overheating, arcing, or sparking failure. Some embodiments may include a fire threat characterization test ignition source, which can be selected as a more severe ignition source than a short circuit occurring in the electric motor and tripped by the engine fuse. In some embodiments, the inverter can detect AC overcurrent and isolate faulty phases and / or continuously monitor the input DC voltage and apply protective actions to keep the voltage below overvoltage operating limits.

[0115] During takeoff, landing, hovering, and cruise, the motors and related control components of a VTOL aircraft can generate heat. Heat dissipation is essential to prevent deterioration or damage to the motors, control components, and other parts of the VTOL aircraft. For some types of VTOL aircraft, such as electric VTOL (eVTOL) aircraft, thermal control is equally important for maintaining optimal energy efficiency for components such as those powered by batteries.

[0116] Some components may generate high heat loads only during certain operating periods. For example, some lift propellers may only be used during takeoff, landing, and hovering, and can be shut off during cruise. Therefore, such lift propellers can generate high heat loads during takeoff, landing, and hovering, and generate little or no heat during cruise.

[0117] B. Exemplary Rotor Assembly Embodiment

[0118] In some embodiments, at least one electric motor may be mechanically connected directly or indirectly to the fuselage of the aircraft and electrically connected to an electric power source. The mechanical connection may involve fastening, attaching, coupling, securing, or engaging. A direct connection may involve the electric motor being connected to the fuselage such that the electric motor contacts or abuts the fuselage. An indirect connection may involve the electric motor being connected to the fuselage such that an intermediate component, such as a wing, boom, or other intermediate component, may exist between the fuselage and the electric motor.

[0119] In some embodiments, an electric propulsion system may include a gearbox assembly. The gearbox can contribute to gear reduction in the electric propulsion system. The gearbox assembly may include multiple gearboxes. For example, in some embodiments, the output of one gearbox assembly may be fed into another gearbox assembly to achieve greater gear reduction. Such embodiments may include at least one sun gear, at least one set of planetary gears, at least one ring gear, and at least one planet carrier. The gearbox may have a common gear, such as a common sun gear, a common planetary gear set, and / or a common ring gear. In some embodiments, the sun gear may be the central gear in a planetary gear train or a planetary gear train. In some embodiments, the sun gear may be an input gear. The embodiments discussed herein can be modified to include multiple gearboxes. In some embodiments, a combination of a sun gear, planetary gears including compound planetary gears, and ring gears can produce gear reduction. Thus, the characteristics of the gears within the gearbox assembly can determine the available gear reduction in the electric propulsion system. In some embodiments, the gear reduction value may be a relevant design standard for VTOL aircraft, as the aircraft may need to apply specific torque values ​​to the propeller assembly to provide the desired or required lift for the payload. The gearbox can help provide torque while minimizing the drag profile and mass of the electric engine. Therefore, the embodiments described herein can provide optimized electric propulsion system designs in terms of drag profile and mass and payload capacity.

[0120] In some embodiments, the electric propulsion system may include an electric motor having a stator and rotor assembly. For example, the electric motor may drive the rotation of the rotor, which in turn drives the rotation of the gearbox, thereby providing gear reduction for the shaft in the electric propulsion system. In some embodiments, the rotor may include multiple magnets. Electromagnetic interaction between the stator and rotor drives the rotation of the rotor, and therefore the magnets in the rotor may be subject to centrifugal forces. It should be recognized that at certain rotational speeds, the magnets may separate from the rotor due to centrifugal forces. For example, centrifugal forces may cause the magnets to move radially outward, thereby spacing the magnets from the rotor, so that there may be a distance between the rotor and the magnets, which may be detrimental to the electromagnetic characteristics of the rotor. Therefore, the magnets may be held to prevent them from separating from the rotor. In some embodiments, the rotor assembly may include a sleeve. The sleeve may hold, wrap, surround, enclose, or contain one or more objects. For example, the sleeve may include a wrapping layer, a sheath, a cap, a shell, or a housing. As discussed herein, the disclosed embodiments may relate to stretchable sleeves capable of expanding or stretching in diameter or circumference. Prefabricated sleeves may include stretchable sleeves such as carbon fiber sleeves.

[0121] Some of the disclosed embodiments relate to methods, systems, and apparatus for manufacturing rotor assemblies, including the assembly and mounting of rotor assembly components. As described herein, the disclosed embodiments of the rotor assembly may involve inserting magnets into prefabricated sleeves, thus eliminating the need to wind materials such as carbon fiber around the magnets after they have been attached to the rotor back iron. Other methods of winding or applying sleeves after magnet assembly may not provide the necessary tension (e.g., preload) to hold the magnets when rotating at the motor's operating speed, thus requiring a larger air gap between the rotor and stator (e.g., the distance between the rotor magnets and the stator copper windings), which reduces rotor efficiency. For example, when winding carbon fiber around the magnets (e.g., where adhesives can be used to secure the magnets to the back iron), the tension used to wind the carbon fiber may not provide optimal preload to hold the magnets. Furthermore, the disclosed embodiments reduce the need to heat the rotor to high temperatures to cure the carbon fiber, which may degrade the strength of the magnets (e.g., reduce the magnetism of the magnets). The disclosed embodiments can also reduce the need for adhesives or filler materials between magnet-to-magnet contact points in the rotor (e.g., the gap created by bonding the two sides of the magnet together), which can improve efficiency, magnetic force, maximum RPM, and mass savings. Furthermore, because the disclosed embodiments can reduce the air gap and the need for adhesives, higher magnetization (e.g., greater magnetic force) can be achieved for a given rotor size, resulting in a more compact and smaller motor.

[0122] Furthermore, the disclosed rotor assembly manufacturing embodiments can prevent magnet and / or sleeve failure (e.g., breakage or damage) during installation. For example, the disclosed embodiments can support and insert the magnet, causing it to expand against the sleeve, thereby generating the required load or sleeve expansion to hold the magnet while preventing shear forces from entering the sleeve, which could lead to sleeve failure. In some embodiments, the magnet insertion tool can support the magnet in a manner that prevents excessive sliding friction, for example, between the two magnet surfaces or between the sleeve surface and the magnet surface, during sleeve expansion. For example, a portion of the sliding friction force can instead be applied to the moving surface of the magnet insertion tool.

[0123] The disclosed embodiments are applicable to any application of the motor, such as any automotive application, alternator, generator, motor manufacturing (e.g., conveyors), etc. For example, the disclosed embodiments may relate to a rotor comprising surface-mount magnets. Furthermore, the disclosed embodiments may improve the efficiency and speed of rotor assembly, including inserting magnets into the rotor. For example, winding carbon fiber around the magnet may take more time than expanding a prefabricated sleeve.

[0124] Figure 11A diagram of a rotor assembly 1100 consistent with embodiments of the present disclosure is shown. The rotor assembly 1100 may include a sleeve 1104 configured to circumferentially surround permanent magnets 1102, 1103 attachable to a laminated core 1108. The rotor assembly 1100 may also include a rotor hub 1106. In some exemplary embodiments, the rotor hub 1106 may hold the laminated core 1108, magnets 1102, and / or sleeve 1104. Rotation of the rotor may cause the magnets to experience centrifugal forces in direction 1116, which may tend to displace or separate the magnets 1102, 1103 from the rotor hub 1106. Some embodiments may involve the use of materials with elastic properties to prevent separation of the magnets from the rotor. Some alternative embodiments may utilize materials such as carbon fiber for direct winding. For example, magnets 1102 / 1103 may be attached to the laminated core 1108, and carbon fiber may be directly circumferentially wound onto the magnets. It should be recognized that conventional systems may involve attaching magnets to the laminated core using adhesives such as glue. The winding of carbon fibers can be performed under high tension to stretch the fibers, thereby applying a preload or pressure to the magnets. This helps to push the magnets against the laminated core 1108, thus preventing magnets 1102 and 1103 from separating. It should be recognized that the greater the tension of the carbon fibers, the greater the preload can be generated, which more effectively applies pressure to the magnets and prevents the magnets from separating from the rotor at operating speeds. For example, operating speeds may include high rotational speeds, which may result in higher centrifugal forces, thus requiring greater preload.

[0125] It is understood that the rotor assembly described herein can be used in a variety of fields, including but not limited to flywheels, automobiles, turbochargers, electric motors, and others. The disclosed embodiments are applicable to fields involving high performance and high efficiency, such as high-performance automobiles (e.g., racing cars). In another example, the disclosed embodiments are applicable to space, including rockets and space exploration vehicles, as such applications may require smaller, more compact engines. Further non-limiting examples may include hobby aircraft (e.g., model aircraft or radio-controlled cars), industrial applications (e.g., automation or manufacturing robots), wind turbines, surgical robots or MRI instruments, marine engines, and consumer appliances. As discussed herein, the centrifugal force generated by the rotor's rotation may cause masses such as magnets to deviate from the rotor's axis of rotation. The disclosed embodiments may include a sleeve (e.g., sleeve 1104) that can hold the magnets and prevent them from separating from the rotor. The sleeve may be stretchable when multiple magnets are circumferentially positioned around it, and the diameter of the sleeve may be increased. In some embodiments, to prevent the magnet from separating from the rotor during rotation, the sleeve may apply a force sufficient to compensate for centrifugal forces, such as the centrifugal force expected at the operating speed. For example, because the sleeve stretches when the magnet is arranged in it, the tension in the sleeve may cause a force to be applied to the magnet in the opposite direction (e.g., radially inward) to the centrifugal force (e.g., which may be radially outward). The sleeve may apply a force to the magnet by preloading it onto the rotor. For example, the sleeve may apply a force to the magnet to press it against the rotor.

[0126] In some embodiments, the rotor assembly may include a plurality of conical magnets. The conical magnets may involve magnets that are narrower, smaller, or tapered in size. For example, a conical magnet may have a first length or width and a second length or width, wherein the second length or width is smaller than the first length or width. In some embodiments, the taper of the conical surface may be determined by characteristics of the rotor assembly, such as the size of the rotor, the amount of expansion required in the sleeve, and the amount of pressure or force expected to be generated in the sleeve. When the magnets are circumferentially arranged within the sleeve, the angle or taper of the conical surface may affect the amount of circumferential displacement, thereby affecting the amount of stretching in the sleeve. In some embodiments, the conical magnets may include a conical surface angle (e.g., a tilt) of 0.1 to 45 degrees. In some examples, the conical magnets may include a conical surface angle of 7 degrees or less on opposite surfaces. For example, the conical magnet may have a trapezoidal shape with a tilt of 0.6 degrees. In some embodiments, the conical magnets may include a tilt of 0.6 degrees on one surface or on opposite surfaces. A plurality of conical magnets may include one or more permanent magnets. In some embodiments, the advantages that conical magnets can provide include reducing the gap between magnets, thereby improving the balance of the rotor assembly.

[0127] exist Figure 11In some embodiments shown, multiple magnets may abut against each other. For example, magnet 1102 may correspond to a first group of magnets and may contact magnet 1103, which may correspond to a second group of magnets. It is understood that tension in sleeve 1104 applies pressure to magnet 1102 to prevent magnet 1102 from separating from the laminated core 1108. For example, tension in sleeve 1104 may apply a preload or holding force in a direction 1114 opposite to the centrifugal force direction 1116. It is understood that the disclosed embodiments incorporating tension in sleeve 1104 can reduce the use of adhesives such as glue, thereby simplifying assembly. For example, it is understood that tension in the sleeve can provide a higher preload force compared to the holding force provided by adhesives, thereby improving the holding force of the magnets. In some embodiments, one of the multiple magnets may abut against at least one magnet.

[0128] Figures 12A-12BAn isometric view of a rotor assembly consistent with embodiments of the present disclosure is shown. In some embodiments, a plurality of magnets may abut against each other along the inner diameter of the sleeve. For example, rotor assembly 1200 includes a first set of tapered magnets 1206A and a second set of tapered magnets 1208A that taper from one side to the other. For example, the width of the first side 1205A may be greater than the width of the second side 1207A. The first side 1205A may be parallel to the second side 1207A. The first tapered side 1211A and the second tapered side 1209A may be inclined relative to the first side 1205A and the second side 1207A. In some embodiments, the first tapered side 1211A and the second tapered side 1209A may form tapered magnets such that the width of the second side 1207A may be smaller than the width of the first side 1205A. The magnets may be positioned along the inner diameter 1204A of the sleeve 1202A. In some embodiments, the conical surface direction of conical magnet 1206A may be opposite to that of conical magnet 1208A. In some embodiments, a plurality of conical magnets may be inserted relative to each other in the circumferential direction. Circumferential insertion may involve placing the magnets along the circumference of the sleeve. The magnet arrangement may be sized such that it fits within the diameter of the sleeve before the magnets are pushed together. For example, magnets 1206B and 1208B of rotor assembly 1200B may be disposed inside sleeve 1202B such that the magnets are distributed on the circumference 1203B of the sleeve. In some embodiments, magnet 1206B may represent a pole magnet. For example, a pole magnet may refer to the magnetic pole direction of the magnet, and the pole magnet may facilitate the primary interaction between the stator and rotor (e.g., driving poles). In an example, magnet 1206B may comprise 14 pole magnets. In some embodiments, magnet 1208B may represent a side magnet. For example, the magnetic force (e.g., attractive force) between the pole magnet and the stator may be stronger than that between the side magnets, which in turn provide the opposing force (e.g., repulsive force). The inclined or tapered side of the first set of magnets 1206A may contact the inclined side of the second set of magnets 1208A. In some embodiments, the tapered magnets may be wedge-shaped, such that when oppositely oriented tapered magnets contact each other, these magnets may generate displacement and stretch the sleeve 1202B. For example, magnet 1206B may have an orientation opposite to that of magnet 1208B, such that the narrow side is on the right side of magnet 1206B and the narrow side is on the left side of magnet 1208B. For example, the wider first side 1205A of magnet 1208A may be closer to the right end 1214A of sleeve 1202A. The narrower second side 1207A of magnet 1208A may be closer to the left end 1212A of sleeve 1202A. The wider first side 1216A of the magnet 1206A can be closer to the left end 1212A of the sleeve 1202A, while the parallel, narrower second side of the magnet 1206A can be closer to the right end 1214A of the sleeve 1202A.

[0129] In some embodiments, a plurality of conical magnets may comprise a first set of conical magnets inserted axially relative to a second set of conical magnets. For example, the conical magnets may be distributed circumferentially, and axial insertion of the conical magnets may involve pushing the magnets toward the center of the sleeve. The magnets may wedge into each other. For example, magnet 1206A may wedge between an adjacent pair of magnets 1206B, and vice versa. Using this arrangement, when each magnet (e.g., 1206A or 1206B) is inserted in the axial direction, the magnet may exert a force in the circumferential direction on its adjacent magnets having opposite conical surfaces, causing the diameter of the magnet arrangement to increase as the opposing magnets push each other apart, thereby stretching the sleeve 1202A and generating tension within the sleeve. In some embodiments, the strain that the sleeve can withstand may help determine the extent to which the sleeve can be stretched without breaking, thereby helping to determine the dimensions of the sleeve (e.g., diameter) and the dimensions of the magnets (e.g., length, width, cone angle). In some embodiments, the magnet insertion tool guides the magnet along its insertion path while reducing the magnitude of the forces exerted by the magnets on each other. For example, in some embodiments, the tapered sides of adjacent magnets may contact each other as they slide relative to each other, but may not press against each other with sufficient force to cause the sleeve to expand. Instead, the expansion force may be applied by the magnet insertion tool that guides the magnet into place. In some embodiments, friction between magnets 1206B and 1208B may hold or lock the magnets in a fixed position. It is understood that in some embodiments, using a pre-made sleeve for circumferential insertion of the magnet provides higher achievable cylindrical stress and pressure to hold the magnet compared to direct winding.

[0130] Figures 13A-13BA side view of a rotor assembly consistent with embodiments of the present disclosure is depicted. The rotor assembly 1300A may include a plurality of first magnets 1304A, the conical surfaces of which are oriented opposite to the conical surfaces of a plurality of second magnets 1308A surrounded by a sleeve 1302A. The disclosed embodiments may involve positioning a plurality of second conical magnets 1308A between adjacent pairs of the plurality of first magnets 1304A. For example, a conical end 1305A corresponding to the plurality of first magnets 1304A may contact a conical end 1307A corresponding to the plurality of second magnets 1308A. As discussed herein, the plurality of magnets may be axially inserted. For example, the plurality of first magnets 1304A may be pushed in a first axial direction 1306A toward a plurality of second magnets 1308A pushed in a second axial direction 1310A. The first axial direction 1306A may be axial relative to the second axial direction 1310A by being along the same axis opposite to the second axial direction 1310A. The magnets can be positioned at a certain axial length, which can be the distance from the central axis of the rotor assembly. For example, the wide end of magnet 1304A can be positioned at a distance 1312A from the axis 1311A of rotor assembly 1300A, such that the conical magnets abut against each other. In this case, sleeve 1302A can have an unstretched diameter 1314A. As the conical magnets are pushed towards each other, the axial distance 1312A can decrease. It should be understood that when the conical magnets are pushed towards each other, the wedge magnets can displace relative to each other in the circumferential direction, thereby increasing the diameter of sleeve 1302A, such that the stretched diameter 1314B of sleeve 1302A is greater than the unstretched diameter 1314A. For example, magnets 1304B and 1308B can be inserted such that their wide ends are at a reduced axial distance 1312B from the central axis 1311B. Therefore, the diameter of sleeve 1302B can expand and stretch, such that sleeve 1302B reaches a stretched diameter 1314B, thereby generating a preload in the sleeve. The stretched diameter 1314B can be an increased diameter of the unstretched diameter 1314A. In some embodiments, rotor assembly 1300B can represent the position of the magnet during operation or in an operating configuration. It should be recognized that this configuration of the rotor assembly may be an improvement over a directly wound carbon fiber rotor assembly. For example, compared to a directly wound rotor assembly, this configuration can provide advantages including the ability to generate greater pressure or tension. Directly wound rotor assemblies may also involve a curing process, and component variations during curing can lead to a loss of preload in the winding. Furthermore, directly wound rotor assemblies may involve a curing process that may take place at high temperatures, which can be detrimental to the permanent magnet and may lead to demagnetization.

[0131] Figure 14AA front view of a rotor assembly consistent with embodiments of the present disclosure is shown. The rotor assembly 1400A may include a sleeve 1402A and a magnet arrangement 1404A. In some embodiments, as described herein, circumferentially inserting a tapered magnet can cause the sleeve 1402A to expand. For example, circumferentially inserting a magnet can cause the sleeve 1402A to expand in direction 1406A, resulting in circumferential expansion of the sleeve 1402A.

[0132] In some embodiments, the plurality of conical magnets include a crown. The crown may include a raised surface on the magnet. For example, the crown may include a raised surface on the top side of the magnet. In some embodiments, the crown abuts against the inner diameter of the sleeve. Figure 14B A partial front cross-sectional view of a magnet assembly consistent with embodiments of the present disclosure is shown. Magnet 1404B may include a crown 1410B on its outer peripheral surface 1412B. Crown 1410B may include a raised surface such that the thickness 1414B of magnet 1404B (e.g., in the radial direction) is greater at center 1416B than at edge 1418B. Crown 1410B may abut against the inner diameter of sleeve 1402A. The interaction between crown 1410B and sleeve 1402A can provide a locking feature that secures the magnet to the sleeve. For example, due to the increased height at the magnet center at crown 1410B, sleeve 1402A can be stretched more at the center and has higher tension at the center. Therefore, the increased tension and friction can provide a holding force and prevent displacement of sleeve 1402A. In some embodiments, the crown 1410B may meet regulatory requirements by providing a retaining force that may be other than sleeve friction retaining force.

[0133] In some embodiments, the rotor assembly may include a laminated core. The laminated core may comprise the core of an electric motor. In some embodiments, the laminated core may be made of a metal such as steel or iron. The laminated core facilitates the movement of magnetic flux between different magnetic poles on the stator or rotor. As discussed herein, a laminated core may refer to a back iron, a steel core, a steel laminate, or a laminated lamination. For example, rotor assembly 1100 includes a laminated core 1108, such as... Figure 11As shown. As discussed herein, magnets in the rotor assembly may contact or be adjacent to the laminated core. In some embodiments, the magnets may have curved or flat surfaces that can contact the laminated core. For example, a plurality of tapered magnets 1404B may include a magnet with a flat side 1406B and a magnet with a curved side 1408B. The flat side 1406B and the curved side 1408B may be the inner diameter of the magnet that contacts the outer diameter of the laminated core. The magnet with the curved side 1408B may have a curve, arch, or arc on the surface of the magnet that abuts the laminated core. The magnet with the flat side 1406B may facilitate the transfer of torque from the magnet to the laminated core. For example, rotation of the magnet and preload generated by the sleeve may generate torque, and said torque may be transferred from the flat side of the magnet to the laminated core, thereby connecting the magnet and the laminated core such that rotation of the magnet causes rotation of the laminated core. In some embodiments, the core may include magnets (e.g., laminated plates, including magnets embedded between or within the plates). In some embodiments, the rotor assembly may not include a core. For example, the rotor's magnets may contact the hub instead of the laminated core. In some embodiments, the magnets may include suitable shapes, such as one or more flat surfaces, flat edges or flat faces, one or more curved faces, or any combination of flat and curved faces.

[0134] Figure 15 A top view of a laminated core consistent with embodiments of the present disclosure is shown. The disclosed embodiments may include a flat section 1504 on the outer diameter of the laminated core 1502. The flat section 1504 may correspond to a magnet or number of poles in a rotor assembly. For example, there may be multiple flat sections corresponding to the number of tapered magnets disposed on the circumference of the rotor assembly. In some embodiments, the laminated core may include at least one notch. The notch may include an area where material has been removed, such as a dent, cut, or groove. For example, the laminated core 1502 includes a triangular notch 1506 below the flat section 1504. In some embodiments, the magnetic flux in the notch region may be reduced. Therefore, metal may not be needed in the region, and removing metal can save mass. Furthermore, notches and cuts may also provide torque transmission characteristics from the rotor laminate to the rotor hub. In some embodiments, torque from the magnet can be transmitted to the laminated core when the flat magnet 1406B engages with the outer diameter of the laminated core 1502, for example, when it contacts the flat section 1504. This configuration, where the flat side of the magnet rests against the flat side of the laminated core, can transmit torque. In some embodiments, the outer diameter of the laminated core rests against at least some of the magnets. For example, as... Figure 11As shown, the outer diameter of the laminated core 1502 can abut against some of the plurality of magnets 1102 or 1103. At least some of the plurality of magnets may comprise one or more magnets or portions thereof. For example, the laminated core 1502 may abut against the flat side of a magnet, as described herein. In some embodiments, the laminated core 1502 may abut against all magnets such that the laminated core abuts against each of the plurality of magnets, or the laminated core contacts a substantial portion of the surface of each of the plurality of magnets. In some embodiments, the laminated core may not include a notch. In some embodiments, the laminated core may be a suitable shape, such as one or more flat sides, a fully curved shape, a circle, or any combination thereof.

[0135] In some embodiments, the rotor assembly may include a rotor hub. The hub may include a disk, a housing, or a central component. The hub may connect one or more components of the rotor assembly. For example, the hub may connect a bearing to the rotor. In some embodiments, the rotor hub may retain at least one of a stacked core, a plurality of tapered magnets, or a sleeve. Retention may involve preventing separation or movement and includes limiting, enclosing, holding, securing, fastening, and / or fixing. The hub may be made of a metal including aluminum. In some embodiments, the rotor assembly may involve one or more rotor hubs.

[0136] Figure 16 An exemplary embodiment of a pair of rotor hubs consistent with embodiments of the present disclosure is shown. For example, the rotor assembly may include a first rotor hub 1602 and a second rotor hub 1604. The first rotor hub 1602 may abut a first side of the laminated core, and the second rotor hub 1604 may abut a second side of the laminated core. In some embodiments, a rotor assembly including two rotor hubs may have advantages such as symmetry, improved thermal expansion, and improved dimensional consistency, which can improve manufacturability and assemblability. The disclosed embodiments of the rotor assembly can reduce radial engagement or contact between the hubs and the laminated core. For example, embodiments including two rotor hubs can reduce contact between the rotor hubs and the inner diameter of the steel core, thereby reducing unnecessary material and reducing weight. In some embodiments, placing a conductive metal such as aluminum near an electromagnetic field, such as near an electromagnetic field in a laminate, may cause short circuits or eddy current losses, which may generate heat and reduce efficiency. The disclosed embodiments minimize the interaction between the rotor hubs and the laminate, thereby reducing eddy current losses and improving efficiency. The rotor hub may include a bore 1608 that allows the rotor hub to be fastened or connected (including by pins, rods, or screws) to other components. As discussed herein, the attachment components (including fastening or connection) may involve any suitable attachment method, such as pins, rods, screws, bolts, or rivets. The first rotor hub 1602 and the second rotor hub 1604 may include protrusions 1606 and 1610. Protrusions 1606 and 1610 may help retain components of the rotor assembly. For example, as Figure 11As shown, a protrusion 1110 on the rotor hub 1106 retains the laminated core 1108, magnets 1102, 1103, and sleeve 1104. The protrusion 1110 extends from the rotor hub 1106 to capture or mechanically engage the laminated core 1108, magnets 1102, 1103, and sleeve 1104, thereby preventing displacement, such as axial displacement, during operation. In some embodiments, displacement (e.g., magnet displacement) may be detrimental to the operation of the electric propulsion system because it may cause sleeve fatigue or require rotor rebalancing. The protrusion 1110 provides additional engagement and retention for components in the rotor assembly, which can further prevent components from separating or dislodging from the rotor, providing an advantage over relying solely on friction to prevent separation or displacement.

[0137] In some embodiments, the rotor hub may include torque transmission features. For example, the first rotor hub 1602 and the second rotor hub 1604 may include one or more protrusions, such as protrusions 1612 and 1614. Protrusions 1612 and 1614 may be pins or raised surfaces on the outer diameter of the first rotor hub 1602 and the second rotor hub 1604. Protrusions 1612 and 1614 may facilitate torque transmission to the rotor hub. For example, protrusions 1612 and 1614 may engage with a notch 1506 on the laminated core 1502. Protrusions 1612 and 1614 may be aligned with a cutout in the notch 1506 such that the protrusion abuts against the cutout. Thus, the laminated core 1502 may be coupled to the first rotor hub 1602 and the second rotor hub 1604 such that rotation of the laminated core 1502 may cause rotation of the rotor hub due to the contact between the notch 1506 and the protrusions 1612 and 1614. For example, as Figure 11 As shown, the torque of the conical magnet 1102 can be transmitted to the laminated core 1108. The contact between the protrusion of the rotor hub 1106 and the recess of the laminated core 1108 at the interface 1112 can help transmit torque from the laminated core 1108 to the rotor hub 1106.

[0138] Figures 17A-17DA cross-sectional view of a rotor assembly consistent with embodiments of the present disclosure is shown. Rotor assembly 1700A may include a first rotor hub 1702A and a second rotor hub 1704A, both of which may surround and hold laminated cores 1706A and 1709A. For example, the first rotor hub 1702A may surround the laminated core 1709A at a first interface 1711A, and the second rotor hub 1704A may surround the laminated core 1709A at a second interface 1713A. The disclosed embodiments may include a gap, space, or interval 1708B between the first rotor hub 1702A and the second rotor hub 1704A. It is understood that engaging the magnets and laminated core 1706A from both sides of the rotor hub provides better mechanical axial holding force compared to holding them from one side. In some embodiments, the rotor hub may provide a radial connection between the bearing and the laminated core. For example, rotor hub 1702A may have a first interface 1708A with the laminated core 1709A, and rotor hub 1704A may have a second interface 1710A with the laminated core 1709A, and these interfaces enable torque transmission from the laminated core to the rotor hub and then to the bearing or input gear. In some embodiments, the rotor hubs may have a gap or clearance, such as a spacing distance 1708B between the first rotor hub 1702B and the second rotor hub 1704B, which allows for the flow of fluids such as coolant. In some embodiments, the rotor hubs may facilitate a response to gyroscopic loads. For example, increasing the spacing distance 1708B between the first rotor hub 1702B and the second rotor hub 1704B may result in an increase in the area moment of inertia. The disclosed embodiments of the various rotor hubs allow for easier adjustment of the rotor assembly, such as easier adjustment of the area moment of inertia connected to the input gear, while maintaining mass savings. For example, increasing the spacing distance 1708B may make the rotor more robust.

[0139] Figure 17CA cross-sectional view of a rotor assembly consistent with embodiments of the present disclosure is shown. Rotor assembly 1700C may include a first rotor hub 1702C and a second rotor hub 1704C. Bearing 1714C and support 1716C may be substantially integrated into sun gear 1712C. Substantial integration may involve bearing 1714C and support 1716C being surrounded or housed within sun gear 1712C. This configuration of bearing 1714C within sun gear 1712C may have several advantages, including preventing bearing 1714C from having to respond to loads (e.g., loads due to tension or pressure in sleeve 1703C), as such pressure or load could cause a reduction in the size of the bearing bore. Instead, as discussed herein, the disclosed embodiments may involve magnet 1701C responding to loads. Therefore, the disclosed embodiments prevent bearing bore deformation or size reduction, thereby ensuring a consistent fit of components during assembly. Magnet 1701C can be held at opposite ends or on the periphery of rotor assembly 1700C. For example, a first rotor hub 1702C can hold the magnet on a first side 1705C of rotor assembly 1700C, and a second rotor hub 1704C can hold the magnet on a second side 1707C of rotor assembly 1700C, thereby improving magnet retention. In some embodiments, bolt 1718C can extend through holes in the second rotor hub 1704C, the first rotor hub 1702C, and the sun gear 1712C to attach and connect these components. For example, bolt 1718C can mechanically connect the first rotor hub 1702C and the second rotor hub 1704C to the sun gear 1712C, such that movement or rotation of the rotor and thus rotation of the rotor hubs causes rotation of the sun gear. In some embodiments, the sun gear can be an input gear, such that rotation of the sun gear drives the input of a gearbox (including a planetary gearbox). For example, the torque path can be from the rotor to the sun gear 1712C, then to the planetary gears, and finally to the spindle, which can be attached to the propeller. As described in this article, the interface between the magnet, the laminated core, and the rotor hub can help transfer torque from the magnet to the sun gear.

[0140] Figure 17DAn enlarged partial cross-sectional view of a rotor assembly consistent with embodiments of the present disclosure is shown. Rotor assembly 1700D may include a bearing 1714D housed within a sun gear 1712D, which prevents the bearing bore from deforming due to load response, thereby providing a consistent bore fit. Furthermore, housing the bearing 1714D within the sun gear 1712D reduces the need for drilling operations, which can introduce thermal expansion mismatches during assembly. The bearing 1714D may include a rolling element 1724D between an inner race 1720D and an outer race 1722D. In some embodiments, the first rotor hub 1702D and the second rotor hub 1704D may include holes for fastening. For example, a bolt 1718D may extend through the second rotor hub 1704D, the first rotor hub 1702D, and the sun gear 1712D, thereby attaching and coupling the sun gear to the rotor hub. The sun gear 1712D may include an internally threaded bolt for securing the bolt 1718D, thus eliminating the need for a nut.

[0141] The disclosed embodiments may relate to methods of assembling rotor assemblies. As discussed herein, the disclosed embodiments may include generating pressure within a prefabricated sleeve. Generating pressure may involve generating a preload by expanding the prefabricated sleeve. The prefabricated sleeve may comprise a sleeve, such as carbon fiber wound on a mandrel. For example, carbon fiber may be wound onto an aluminum cylinder serving as a mold under low tension. Sleeve curing may require high temperatures, followed by cooling and removal of the sleeve. Thus, by stretching the cured composite material, the load can be uniformly distributed within the fibers, and higher tensile or circumferential stresses can be achieved. The disclosed embodiments may improve the mounting and stretching of the sleeve, for example, stretching the sleeve onto the rotor. For example, the prefabricated sleeve can be expanded by circumferentially inserting a magnet arrangement. Figure 12A As shown, the magnet arrangement may include a plurality of first conical magnets 1206A and a plurality of second conical magnets 1208A. When the plurality of first conical magnets 1206A and the plurality of second conical magnets 1208A are axially pushed against each other while surrounded by a sleeve 1202A, the sleeve 1202A can expand because the conical magnets act as wedges to each other. In some embodiments, each of the plurality of first magnets and each of the plurality of second magnets can be pushed together simultaneously. In some embodiments, the prefabricated sleeve allows for the use of a wider variety of resins or curing processes because it avoids limitations caused by exposing temperature-sensitive magnets to higher curing temperatures. Therefore, the prefabricated sleeve can shorten curing time and cycle time. The prefabricated sleeve can provide greater flexibility in material selection, such as selecting highly characteristic materials, which can simplify regulatory approval processes.

[0142] Figures 18A-18FAn assembly process for a rotor assembly consistent with embodiments of this disclosure is shown. The magnet arrangement assembly 1802A may include a tapered magnet 1801A inserted into an expansion sleeve 1803A. The disclosed embodiments may involve inserting a laminated core. For example, a laminated core 1804A may be inserted into the magnet assembly arrangement 1802A by, for example, press fitting, to form a torque ring assembly 1806B, as... Figure 18B As shown. Press fit may include compensation for various component tolerances. In some embodiments, the laminated core 1804A can be inserted into the magnet assembly arrangement via a stretch sleeve. As discussed herein, the tapered magnets are pushed against the stretch sleeve, increasing the sleeve's diameter. In some embodiments, during assembly, the magnets can be pushed against each other further than they would be during operation, thereby stretching the sleeve to a diameter larger than the stretched diameter during operation. For example, refer to... Figure 13B During assembly, magnet 1304B can be pushed against magnet 1308B such that the axial length of the magnet is less than the axial length 1312B. Therefore, as the magnets push against each other further, the amount of contact on the conical surfaces of the magnets increases, thereby increasing the amount of expansion in the sleeve, making the sleeve diameter larger than the stretching diameter 1314B. The laminated core 1804A can then be inserted into the magnet assembly arrangement 1802A, which has an expansion diameter (e.g., exceeding its operating diameter). Therefore, in some embodiments, the laminated core 1804A can be inserted without shrinking the fitted laminated core. After insertion, the magnet can be pushed to the axial displacement amount during operation. Therefore, as the amount of contact on the conical surfaces of the magnets decreases, the stretching amount, and thus the sleeve diameter, also decreases. As a result, the sleeve and magnet arrangement apply tension to the laminated core, thereby securing or engaging it.

[0143] In some embodiments, the outer diameter 1805A of the laminated core 1804A may abut against the inner diameter 1807A of the magnet assembly arrangement 1802A. The disclosed embodiments may involve attaching at least one rotor hub to the laminated core. For example, refer to... Figure 18B The first rotor hub 1808B can be attached to the first side 1807B of the torque ring assembly 1806B, and the second rotor hub 1810B can be attached to the second side 1809B of the torque ring assembly 1806B, thereby forming Figure 18CThe rotor assembly 1812C is shown. Attachment may include thermal fitting, such as using liquid nitrogen to shrink the aluminum hub. For example, the hub may be aligned with or placed within a steel core, heated to expand and attach to the steel core, and then cooled to operating temperature. The disclosed embodiments may relate to a balanced rotor assembly. In some embodiments, the rotor may be unbalanced, for example, with mass imbalance or inconsistent weight distribution. It should be recognized that an unbalanced rotor may shorten rotor life, reduce efficiency, and increase vibration. In some embodiments, the rotor assembly 1812C may be balanced by machining away material or machining away added material to compensate for the imbalance. For example, where additional mass is required to achieve a uniform weight distribution, material such as rivets may be added to the rotor, or material may be subtracted from the rotor.

[0144] Figures 18D-18F An assembly process for a rotor assembly consistent with embodiments of this disclosure is shown. The disclosed embodiments may involve inserting a bearing into the sun gear. For example, refer to... Figure 18D The support member 1816D and the bearing 1818D can be pushed into or press-fitted into the sun gear 1814D to form the input gear assembly 1815E, such as... Figure 18E As shown. The support member 1816D can help respond to axial loads. The disclosed embodiments may involve attaching a sun gear to at least one rotor hub. For example, the input gear assembly 1815E may be attached to the rotor assembly 1812E to form a rotor gear assembly 1822F, as... Figure 18F As shown. The input gear assembly 1815E can be attached to the rotor assembly 1812C via bolts 1820E. For example, bolts 1820E can extend through holes in the second rotor hub 1810B, the first rotor hub 1808B, and a hole 1817D on the input gear assembly 1815E to attach the components together and connect them. In some embodiments, the rotor gear assembly 1822F can be balanced by adding rivets and magnetization, etc. It is understood that the disclosed embodiments can involve assembly or manufacture by any suitable method, including but not limited to press fits, interference fits, thermal fits, shrinkage fits, or form fits.

[0145] Figure 19An exploded view of a rotor assembly consistent with embodiments of this disclosure is shown. The rotor assembly 1900 may include a bearing 1906 and a support 1904, both of which are accommodated within a sun gear 1902. A sleeve 1910 may hold a magnet arrangement 1909 and may be inserted into a laminated core 1912 such that the outer diameter of the laminated core abuts against the inner diameter of the magnet arrangement 1909. A first rotor hub 1914 and a second rotor hub 1908 may be attached to the laminated core by means of thermal fitting or the like. Bolts 1916 may secure the rotor assembly 1900 by fastening the first rotor hub 1914 to the second rotor hub 1908 and the sun gear 1902, thereby connecting the laminated core 1912 and the magnet arrangement 1909 due to press fits and shrink fits as described herein.

[0146] Figure 20 A cross-sectional view of a rotor assembly consistent with embodiments of the present disclosure is shown. A magnet 2004 may be disposed around the inner diameter of a sleeve 2002. In some embodiments, the magnet 2004 may be tapered and inserted circumferentially, causing the sleeve 2002 to stretch and exert pressure on the magnet 2004. A laminated core 2006 may contact the magnet 2004, and a first rotor hub 2010 and a second rotor hub 2008 may be attached to the laminated core 2006. The rotor hubs may include protrusions, such as protrusion 2012 on the first rotor hub 2010, which may help retain the laminated core 2006, the magnet 2004, and the sleeve 2002. Bolts 2020 may fasten a sun gear 2014 to the first rotor hub 2010 and the second rotor hub 2008. A support 2016 and a bearing 2018 may be accommodated within the sun gear 2014 such that loads can be responsive to the magnet 2004 rather than the bearing 2018. As discussed in this paper, the laminated core 2006 may include a triangular notch 2022.

[0147] Figures 21A-21B A cross-sectional view of an alternative rotor assembly consistent with embodiments of the present disclosure is shown. Rotor assembly 2100A may include a magnet 2102A held by a sleeve 2104A. Rotor hub 2106A may contact a sun gear 2108A and a bearing 2110A. In some embodiments, magnet 2102B may be radially positioned and surrounded by a sleeve 2014B.

[0148] It should be recognized that during operation of the rotor assembly, the magnets may experience high heat or temperature rise, which may affect performance or efficiency. For example, high temperatures may cause demagnetization. The disclosed embodiments may involve cooling of the magnets in the rotor. The magnets may be cooled by heat exchange or heat transfer (e.g., convection). In some embodiments, a fluid such as a coolant may exchange heat with the conical magnet to provide cooling. As a non-limiting example, the fluid and coolant may comprise air, glycerin, and oil. In some embodiments, the fluid used to cool the magnets may also be used as a lubricant in an electric propulsion system. In some embodiments, the magnets may be indirectly cooled. Indirect cooling may involve cooling without the coolant contacting the magnet. For example, fluid 2112A may be directed to rotor hub 2106A, as... Figure 21A As shown. Fluid 2112A can contact rotor hub 2106A and indirectly cool magnet 2102A by providing heat exchange through rotor hub 2106A. For example, fluid 2112A can contact rotor hub 2106A, and rotor hub 2106A can be press-fitted with laminated core 2107A, so heat exchange can be transferred to rotor hub 2106A, laminated core 2107A, and magnet 2102A.

[0149] The disclosed embodiments may involve at least one cavity disposed between a plurality of tapered magnets and a laminated core. The cavity may include spaces such as gaps, holes, channels, outlets, or chambers. For example, the space between a magnet in a plurality of tapered magnets and the laminated core may form a cavity. In some embodiments, as described herein, the cavity may be a gap between the laminated core and a magnet having a curved surface. In some embodiments, the cavity may be configured to guide fluid for cooling. Being configured to guide fluid may involve guiding the movement of a fluid (e.g., oil). For example, the cavity may guide fluid by directing fluid toward a magnet. For example, the cavity may be very small, such as having a diameter or height of 200 micrometers.

[0150] Figure 22A cross-sectional view of a rotor assembly consistent with embodiments of this disclosure is shown. The rotor assembly 2200 may include a laminated core 2210 in contact with a conical magnet 2208, which may be held by a sleeve 2205. In some embodiments, fluids such as oil may be distributed throughout the electric propulsion system. For example, oil may be distributed to and lubricate the sun gear 2212 or bearing 2214. It should be appreciated that the rotor and sun gear 2212 can rotate, thereby subjecting the oil to centrifugal force. For example, oil flowing near the sun gear 2212 or bearing 2214 may be subject to centrifugal force and may be directed to the rotor hub. Centrifugal force may drive or splash the oil, such that oil enters the gap 2201 between the first rotor hub 2216 and the second rotor hub 2218, and centrifugal force may drive the oil toward the laminated core 2210 in direction 2204. For example, oil may travel in the gap provided by the spacing distance 1708B between the first rotor hub 1702B and the second rotor hub 1704B, as... Figure 17BAs shown. In some embodiments, the laminated core or at least one cavity can directly cool multiple conical magnets. Direct cooling can involve heat transfer when a fluid (e.g., coolant) comes into contact with the magnets. For example, direct cooling can involve heat exchange between the magnets and oil in contact with the magnets. In some embodiments, the laminated core 2210 may include walls 2220 and 2222 such that as oil moves toward the laminated core 2210 in direction 2204, oil forms an oil pool, such as an oil sump 2224. Centrifugal force or pressure can drive the oil out of the oil sump and into the cavity 2202 through opening 2226. In some embodiments, opening 2226 may be provided to allow the flow of fluids such as coolant. For example, opening 2226 may be a leak path or orifice such that pressure drives oil through opening 2226 and into the cavity 2202. The cavity 2202 may be disposed between the magnet 2208 and the laminated core 2210. Oil may reside in the cavity 2202 such that the oil can contact the magnet 2208 and provide cooling. For example, oil can directly contact magnet 2208 to provide heat exchange. In some embodiments, centrifugal force can drive the oil along direction 2206, causing the oil to contact different portions of magnet 2208, such as the side or axial surfaces and end or inner diameter surfaces of tapered magnet 2208, thereby increasing the surface area of ​​the magnet undergoing heat transfer. It is understood that the laminated core and the cavity that allows direct cooling of the magnet improve cooling and heat transfer. For example, as oil travels through an opening, it may be a fluid flowing over a small area, and therefore at a higher speed, thus increasing the heat transfer coefficient. In addition, applying oil directly to portions of magnet 2208 can increase the surface area of ​​the magnet undergoing heat transfer compared to indirect cooling, thereby increasing the heat transfer rate. Furthermore, direct cooling can reduce thermal resistance because the oil exchanges heat with the magnet rather than conducting heat through other components. In some embodiments, fluids such as oil can return from the cooled magnet 2208 to a distribution channel or reservoir through leakage channels, cavities, or holes in the laminated core 2210.

[0151] Figures 23A-23B A front view of a rotor assembly consistent with embodiments of the present disclosure is shown. In some embodiments, rotor assembly 2300A may include one or more cavities 2302A distributed circumferentially. For example, a cavity may be an oil outlet, such as a cavity 2302B located between some portions of the laminated core 2304B and the tapered magnet 2306B. The tapered magnet 2306B may include an inner diameter surface 2308B in direct contact with oil in the cavity 2302B. For example, the inner diameter surface 2308B may include a curved side or a curved surface 1408B, such as... Figure 14B As shown. In some embodiments, cavity 2302B may include the space between a stacked core 2304B and a magnet having a curved surface 1408B, such as Figure 14BAs shown. It is understood that, since the cavity may be located between the laminated core and the magnet with a curved surface, torque transmission can still be provided through the flat side of the magnet, such as the magnet 1406B that may rest against the laminated core 2304B.

[0152] Some of the disclosed embodiments may involve the fabrication (e.g., assembly) of a rotor assembly, which may involve the use of various tools. It is understood that the fabrication of the rotor assembly may involve the assembly of a magnet ring, which may achieve high tension (e.g., preload) within a retaining sleeve to hold the magnets during operation. For example, the magnet ring may refer to magnet arrangement assembly 1802A and may include a tapered magnet 1801A inserted within an expansion sleeve 1803A, as... Figure 18A As shown. Therefore, it is understood that the disclosed rotor assembly manufacturing embodiments can be configured to produce rotor assemblies with sufficient tension, as described herein, without degrading the strength of the rotor assembly (e.g., by damaging the magnet or by breaking the sleeve). It is further understood that the disclosed embodiments for manufacturing rotor assemblies are not limited to tapered magnets. In some embodiments, the magnet includes a tapered surface in the axial direction, such as Figure 12A As shown. In some embodiments, the magnet may include multiple conical surfaces, such as a conical surface in the axial direction and one or more conical surfaces in the radial direction of the sleeve. In some embodiments, the magnet may be rectangular with straight-edge contact between the magnets (e.g., without axial conical surfaces).

[0153] In some embodiments, manufacturing the rotor assembly may involve a magnet insertion tool. The magnet insertion tool can help provide support and various movements to assemble the magnets into a predetermined design. In some embodiments, the magnet insertion tool may include tools such as presses and mandrels. For example, Figures 24A-24G A mandrel and mandrel components for manufacturing a rotor assembly, consistent with embodiments of this disclosure, are shown.

[0154] Figures 24A-24GA mandrel of a magnet insertion tool consistent with embodiments of this disclosure is shown. The expansion mandrel 2400A can be any mandrel (e.g., a shank) used to support and / or hold a component during manufacturing. The expansion mandrel 2400A can be configured to secure or guide a component while expanding and contracting radially from the alignment shaft 2404A. For example, the expansion mandrel 2400A can be configured for movement between a retracted state and an expanded state. For example, in the retracted state, the expansion mandrel 2400A may have a retracted mandrel diameter 2402A between the opposing outer surfaces of push rods 2408A or 2410A, while in the expanded state it has a larger expansion diameter. The expansion mandrel 2400A may include the alignment shaft 2404A, which can assist in maintaining radial alignment of the component during manufacturing. The alignment shaft 2404A can be keyed to include a groove 2406A, which can help lock the alignment shaft 2404A to components (e.g., guide plates and / or support plates) of the expansion mandrel 2400A. In some embodiments, the expansion mandrel 2400A may include push rods for transmitting force and motion to rotor assembly components such as magnets. For example, the push rods may be made of metal and may expand from and contract to the retracted mandrel diameter 2402A. The expansion mandrel 2400A may include push rods according to a predetermined magnet configuration (e.g., the magnet ring configuration described herein). For example, a first push rod 2408A may correspond to a first set of conical magnets, and a second push rod 2410A may correspond to a second set of conical magnets. In some embodiments, the first set of conical magnets may be larger than the second set of conical magnets; similarly, the first push rod may be larger than the second push rod in the circumferential direction. For example, in some embodiments, the first set of conical magnets may include pole magnets of the rotor assembly, while the second set of conical magnets may include side magnets of the rotor assembly, which may be smaller than the pole magnets. Therefore, in some embodiments, the first push rod 2408A may include a pole push rod 2408A configured to act on a pole magnet serving as a first set of conical magnets, and the second push rod 2410A may include a side push rod configured to act on a side magnet serving as a second set of conical magnets. Thus, the first push rod 2408A and the second push rod 2410A may sometimes be referred to as a pole push rod 2408A and a side push rod 2410A, respectively. In some examples, the alignment shaft 2404A may extend through the length of the push rod in the expansion mandrel 2400.

[0155] Figures 24B-24C A push rod for an expansion mandrel consistent with an embodiment of this disclosure is shown. Figure 24B The side magnet push rod 2410B of the expansion mandrel 2400A can be shown, and Figure 24CA pole magnet pusher 2408C of the expansion mandrel 2400A can be shown. In some embodiments, manufacturing the rotor assembly may involve using tapered surfaces in a magnet insertion tool or in components of the rotor assembly. For example, components of the magnet insertion tool may include tapered elements configured to perform insertion movements, including movements during the expansion of the expansion mandrel 2400A. A side magnet pusher 2410B may include a first tapered surface 2412B and a second tapered surface 2414B, and the pole magnet pusher 2408C may similarly include a first tapered surface 2412C and a second tapered surface 2414C. The magnet insertion tool may also include features that facilitate component alignment and positioning, such as by guiding the component during expansion and / or retraction. For example, the side magnet pusher 2410B may include a recess 2416B (and the pole magnet pusher 2408C may include a recess 2416C) for guiding the pusher in the radial direction during operation while constraining the pusher in the axial and circumferential directions. A recess can refer to any groove or indentation, such as a partially hollowed-out portion of a push rod. In another example, the side magnet push rod 2410B may include a stop surface 2418B along its inner side 2422B, and the pole magnet push rod 2408C may include a stop surface 2418C along its inner side 2422C. In some embodiments, the side magnet push rod 2410B may include an outer side 2420B, which may be the outer surface of the expansion mandrel 2400, and the pole magnet push rod 2408C may also include an outer surface 2420C. In some embodiments, the push rod may be configured to assist in pushing, driving, or otherwise advancing a magnet into an assembled configuration. For example, the pole magnet push rod 2408C may be configured to push a plurality of first magnets, such as pole magnets, and the side magnet push rod 2410B may be configured to push a plurality of second magnets, such as side magnets. In some embodiments, the push rod can push one or more components configured to support or hold a magnet, such as the wedges 2510B and 2510C discussed below.

[0156] Figure 24DA vertical cross-section 2400D of an expansion mandrel 2400A for a magnet insertion tool, consistent with embodiments of this disclosure, is shown. Cross-section 2400D may be a cross-section passing through a pole pusher 2408B. As described herein, the magnet insertion tool may include components for guiding pusher movement, such as a pusher guide plate 2422D and a stop plate 2424D. The pusher guide plate 2422D may engage with the inner side 2420D of the pole pusher 2408B for alignment during expansion and / or retraction movements. The stop plate 2424D may engage with the inner side 2420D of the pole pusher 2408B to provide a stop point for retraction (e.g., an expansion initiation point). In some examples, the guide plate 2422D and the stop plate 2424D may engage with the inner side 2420D remote from the first conical surface 2412D and the second conical surface 2414D. Alignment axis 2404D may extend within a ring formed by pole magnet push rod 2408D and side magnet push rod 2410D, passing through one or more guide plates 2422D and stop plates 2424D. In some embodiments, alignment axis 2404D may be configured to align with one or more push rod guide plates and / or stop plates. For example, push rod guide plate 2422D may be concentric with alignment axis 2404D, such that push rod guide plate 2422D remains aligned with alignment axis 2404D.

[0157] Figure 24E Guide plate 2422E and stop plate 2424E consistent with embodiments of this disclosure are shown. Guide plate 2422E may include an interface, such as a slot or recess, for alignment components. For example, pole slot 2426E may engage with recess 2416C of pole push rod 2408C. As another example, side slot 2428E may engage with recess 2416B of side push rod 2410B. During expansion, pole push rod 2408C may slide radially along pole slot 2426E of guide plate 2422E. In some embodiments, the interface between guide plate 2422E and pole slot 2426E or side slot 2428E of push rod may reduce unwanted vertical movement of push rod (e.g., vertical movement relative to alignment axis). Stop plate 2424E may provide a stop point for push rod retraction. For example, the inner side 2420D of the push rod 2408B can contact the surface 2430E of the stop plate 2424E during retraction. (Reference) Figure 24D The guide plate 2422D and the stop plate 2424D can be stacked to provide additional alignment and guidance.

[0158] Figure 24F An expansion mandrel 2400 in a retracted configuration 2430F, consistent with embodiments of this disclosure, is shown, and Figure 24GAn expansion mandrel 2400 in expansion configuration 2430G is shown. For example, the side push rod 2410G and pole push rod 2408G in expansion configuration 2430G can expand to an expansion diameter 2432G, which can be larger than the retracted diameter 2402F of the side push rod 2410F and pole push rod 2408F in retraction configuration 2430F. In expansion configuration 2430G, pole push rod 2408G can be further displaced along groove 2426G compared to pole push rod 2408F along groove 2426F.

[0159] Figures 25A-25F A first view of other components of a magnet insertion tool consistent with embodiments of the present disclosure is shown, as well as a method for manufacturing a rotor assembly. Figure 25A Step 2500A is illustrated, which may involve loading a support plate 2502A onto a conical member 2504A. The conical member 2504A can be any structure with beveled edges. In some embodiments, the conical member 2504A may have a tapered surface that matches the tapered surface of the push rod described herein. The tapered surface of the conical member 2504A may engage with the tapered surfaces of one or more push rods. For example, the bevel angle of the conical member 2504A may be complementary to the angles of one or more of the first tapered surface 2412B, the second tapered surface 2414B, the first tapered surface 2412C, or the second tapered surface 2414C, respectively, with reference to... Figure 25B and Figure 25C In some embodiments, the inclination (e.g., angle) of the conical surface in the conical member 2504 can be such that the axial movement of the sleeve can be proportional to or equal to the radial expansion of the sleeve. In some embodiments, as described herein, the conical surface of the conical member and / or the conical surface of the push rod can be proportional to the conical surface of the conical magnet.

[0160] Figure 25B Step 2500B is shown, which may involve loading the expansion mandrel 2506B onto the support plate 2502B. The expansion mandrel 2506B may be similar to... Figure 24A The expansion mandrel 2400A is shown. In some examples, the alignment shaft 2508B may extend through the support plate 2502B.

[0161] Figure 25CStep 2500C is illustrated, which may involve loading a plurality of first magnets 2512C. In some embodiments, as described herein, the plurality of first magnets 2512C may refer to one or more side magnets. In some embodiments, the plurality of first magnets 2512C may refer to one or more pole magnets. The plurality of first magnets 2512C may be actuated by push rods corresponding to the magnets. For example, when the plurality of first magnets 2512C includes side magnets, push rod 2514C may be a side magnet push rod. In another example, when the plurality of first magnets 2512C includes pole magnets, push rod 2514C may be a pole magnet push rod. In some embodiments, the plurality of first magnets 2512C may be supported by one or more wedges 2510C. A wedge may refer to any component capable of supporting a magnet, such as by holding and / or securing the magnet. For example, wedge 2510C may be located in a groove 2516C of a support plate 2502C (e.g., a base). The slot can be configured to allow radial movement of the wedge 2510C relative to the support plate 2502C. For example, during expansion, the magnet insertion tool may involve pushing a plurality of first magnets radially outward (relative to the support plate 2502C) such that the wedge 2510C, which receives a plurality of first magnets 2512C, slides along the slot 2516C. In other examples, the plurality of magnets may be in direct contact with the push rod. For example, in some embodiments, the plurality of first magnets 2512C may be kept stationary in the axial direction during assembly. In this case, relative axial sliding movement between the push rod 2514C and the wedge 2510C may not be required, and the two components may be integrally formed. In some embodiments, when one of the plurality of magnets is kept stationary in the axial direction and the plurality of first and second magnets are not unequal in size, it may be desirable for the larger magnet to remain stationary. This can minimize wear or strain on the inner surface of the sleeve during insertion.

[0162] In some embodiments, the plurality of second magnets may include the same number of magnets as the plurality of first magnets. In some embodiments, the plurality of second magnets may include a different number of magnets than the plurality of first magnets. For example, the plurality of second magnets may be, for example, half or one-third of the plurality of first magnets, or the plurality of second magnets may have two or one magnet. It should be recognized that as the number of inserted magnets decreases (e.g., or the total circumferential surface area of ​​the inserted magnets facing the sleeve decreases), the stretching of the sleeve may become less uniform, which may increase the risk of failure points (e.g., sleeve bending) in the sleeve.

[0163] Figure 25DStep 2500D is illustrated, which may involve loading sleeve 2518D. In some embodiments, loading sleeve may be performed after loading a plurality of first magnets. In some embodiments, loading sleeve may be performed after loading a plurality of first magnets and a plurality of second magnets. Sleeve 2518D may represent any sleeve described herein, such as sleeve 1202A, as... Figure 12A As shown. For example, sleeve 2518D may comprise carbon fiber. In some examples, the sleeve can be loaded into the magnet insertion tool by mounting sleeve 2518D onto a plurality of first wedges 2512D. In some embodiments, the expansion mandrel 2506D may be in a retracted configuration when the sleeve is loaded. Wedges (e.g., wedge 2510D) may support the sleeve and prevent it from falling off in the axial direction.

[0164] Figure 25E Step 2500E is illustrated, which may involve loading a plurality of second magnets 2520E. In some embodiments, as described herein, the plurality of second magnets 2520E may refer to one or more side magnets. In some embodiments, the plurality of second magnets 2520E may refer to one or more pole magnets. The plurality of second magnets 2520E may be actuated by push rods corresponding to the magnets. In some embodiments, the plurality of second magnets 2520E may be supported by one or more wedges 2522E. The plurality of second magnets 2520E may be loaded such that they are radially inward (e.g., on the inner diameter of the sleeve) of the sleeve 2518E. For example, the plurality of second magnets 2520E may be partially inserted into the sleeve 2518E and the plurality of first magnets.

[0165] Figure 25F Step 2500F is illustrated, which may involve loading the upper plate and performing an insertion movement. The insertion movement can be any movement, action, or manipulation of a component manufacturing the rotor assembly. In some embodiments, the insertion movement may refer to the movement of one or more sets of magnets. In some embodiments, the insertion movement may refer to a component configured to hold the magnets. The insertion movement may include the movement of a wedge that accommodates the magnets. In an example, the insertion movement may involve moving a wedge 2510F (e.g., corresponding to a plurality of first magnets) toward the sleeve 2518F by pressing the lower plate 2526E, etc. In another example, the insertion movement may involve axially moving a wedge 2522F (e.g., corresponding to a plurality of second magnets) toward the sleeve 2518F by pressing the upper plate 2524F, etc. In another example, the insertion movement may involve moving wedges 2510F and 2522F by pressing both the upper plate 2524F and the lower plate 2526F (e.g., simultaneously), etc.

[0166] Figures 26A-26B A wedge for a magnet insertion tool consistent with an embodiment of this disclosure is shown. Figure 26AA first magnet wedge 2600A consistent with embodiments of the present disclosure is shown. In some embodiments, the first magnet wedge 2600A may accommodate one or more of a plurality of first magnets. For example, the first magnet wedge 2600A may hold one or more pole magnets, and a set of first magnet wedges 2600A may correspond to a set of pole magnets. The first magnet wedge 2600A may include a loading surface 2602A, which may be a surface of the wedge 2600A configured to support the z-axis (e.g., axial) loading of the magnet during insertion. The first magnet wedge 2600A may also include an outer surface 2604A, which may be a surface configured to support the back surface (e.g., a flat surface) of the magnet. In some examples, the loading surface 2602A may extend further radially than the outer surface 2604A. For example, the outer surface 2604A may be recessed relative to the loading surface 2602A. The first magnet wedge 2600A may include an inner surface 2606A. For example, the inner surface 2606A may be in contact with a push rod (e.g., a pole magnet push rod) of a magnet insertion tool, such that movement of the expansion mandrel acting on the push rod can move the first magnet wedge 2600A (e.g., apply a force to the first magnet wedge). The first magnet wedge 2600A may also include a bottom surface 2608A that can move along a lower support plate during the expansion and / or contraction of the mandrel, for example, within the groove 2516C described above.

[0167] Figure 26BA second magnet wedge 2600B consistent with embodiments of this disclosure is shown. In some embodiments, the second magnet wedge 2600B may accommodate one or more of a plurality of second magnets. For example, the second magnet wedge 2600B may hold one or more side magnets, and a set of second magnet wedges 2600B may correspond to a set of side magnets. The second magnet wedge 2600B may include a loading surface 2602B, which may be a surface of the wedge 2600B that can set the height of the magnet relative to the sleeve and provide axial load support during insertion. The second magnet wedge 2600B may also include an outer surface 2604B, which may be a surface configured to support the back surface of the magnet (e.g., a flat surface). In some examples, the loading surface 2602B may extend further radially than the outer surface 2604B. For example, the outer surface 2604B may be recessed relative to the loading surface 2602B. The second magnet wedge 2600B may include an inner surface 2606B. For example, the inner surface 2606B may be in contact with a push rod (e.g., a side magnet push rod) of a magnet insertion tool, such that movement of the expansion mandrel acting on the push rod can move the second magnet wedge 2600B (e.g., apply a force to the second magnet wedge). The second magnet wedge 2600B may also include a top surface 2610B that can move along an upper support plate (e.g., in a slot in the upper support plate) during the expansion and / or contraction of the mandrel. In some examples, the second magnet wedge 2600B may be held and / or supported by a pin and by a locking mechanism or annular support structure via the upper support plate.

[0168] Figures 27A-27G A second view of other components of a magnet insertion tool consistent with embodiments of the present disclosure is shown, as well as a method for manufacturing a rotor assembly. Figure 27AStep 2700A of an apparatus and method for manufacturing a rotor assembly is shown. In some embodiments, the axial direction 2701A may refer to the axial direction of the sleeve (e.g., along the axis of the alignment shaft 2705A), while the radial direction 2703A may refer to the radial direction of the sleeve (e.g., along the radius of the alignment shaft 2705A). In some embodiments, the magnet insertion tool as described herein may include an upper tool portion 2702A and a lower tool portion 2704A. However, the disclosed embodiments of the magnet insertion tool are not limited thereto, and for ease of illustration, the magnet insertion tool may be referred to as an upper tool portion and a lower tool portion. In some embodiments, the lower tool portion 2704A may include an expansion mandrel 2706A, which may include a plurality of first push rods 2708A that contact a plurality of first magnet wedges 2710A. In the example, the plurality of first magnet wedges 2710A may be configured to hold a plurality of first magnets, such as a plurality of pole magnets (e.g., the magnet wedges 2710A may be pole magnet wedges). In some embodiments, a plurality of first magnetic wedges 2710A may slide relative to the surfaces of a plurality of first push rods 2708A. For example, the inner surface of the magnetic wedge may contact the outer surface of the push rod and may slide along the outer surface of the push rod. A plurality of second push rods 2712A may contact a plurality of second magnetic wedges 2714A, which may be attached to the upper tool portion 2702A. In an example, the plurality of second magnetic wedges 2714A may be configured to hold a plurality of second magnets, such as a plurality of side magnets (e.g., the magnetic wedges 2714A may be pole magnet wedges). In some embodiments, the plurality of second magnetic wedges 2714A may slide relative to the surfaces of a plurality of second push rods 2712A. It is understood that because the wedges accommodating the magnets can slide along the push rods during push rod and / or wedge movement, the magnet insertion tool can reduce the amount of frictional force applied to the magnets themselves, thereby protecting the integrity of the magnets. For example, the wedges 2714A may expand the sleeve diameter to a diameter slightly larger than that the sleeve might expand to simply by the action of inserting the magnet. This allows the magnet to slide into place without applying excessive force to its surface. When the expansion mandrel retracts again, the sleeve can shrink to its final diameter, thus holding the magnet in place.

[0169] In some embodiments, the lower tool portion 2704A may include a support plate 2716A configured to support a plurality of first magnetic wedges 2710A. For example, the magnetic wedges 2710A may be located in slots in the support plate 2716A such that the support plate 2716A can support loads on the magnetic wedges 2710A in the axial direction 2701A. Furthermore, the magnetic wedges 2710A may be configured to move relative to the support plate 2716A in the radial direction 2703A. For example, during expansion and / or contraction, the magnetic wedges 2710A may slide along slots in the support plate 2716A (e.g., relative to the surface of the support plate 2716A). In some embodiments, the upper tool portion 2702A may include a support plate 2720A configured to support a plurality of second magnetic wedges 2714A. For example, the magnetic wedge 2714A can be disposed in a groove in the support plate 2720A, such that the support plate 2720A can support the load on the magnetic wedge 2714A in the axial direction 2701A. In another example, the magnetic wedge 2714A can be supported by a support ring, as described herein. The upper tool portion 2702A can be configured to hold the magnetic wedge 2714A when suspended above the lower tool portion 2704A. Furthermore, the magnetic wedge 2714A can be configured to move relative to the support plate 2720A in the radial direction 2703A. For example, during expansion and / or contraction, the magnetic wedge 2714A can slide or glide along the groove in the support plate 2720A.

[0170] Figure 27B Step 2700B of an apparatus and method for manufacturing a rotor assembly is shown. In the example, the upper tool portion 2702B may be separate from the lower tool portion 2704B. Some disclosed embodiments may involve loading a plurality of first magnets into a magnet insertion tool. For example, magnets from a plurality of first magnets 2722B may be loaded onto a plurality of first wedges 2710B. The wedges 2710B may support the magnets 2722B in the axial direction 2701B (e.g., support a load on the magnets) and / or support the rear of the magnets 2722B. In some embodiments, the plurality of first magnets 2722B may be pole magnets. In some embodiments, the insertion movement may involve moving the plurality of first magnets 2722B in the radial direction 2703B. For example, an expansion mandrel 2706B may be configured to move a plurality of first push rods 2708B in contact with the plurality of first wedges 2710B, thereby moving the magnets 2722B in the radial direction 2703B. In some embodiments, the plurality of first magnets may be tapered along the axial direction 2701B. In some embodiments, the plurality of first magnets 2722B may be side magnets.

[0171] Figure 27CStep 2700C of an apparatus and method for manufacturing a rotor assembly is shown. Some of the disclosed embodiments may involve loading a sleeve into a magnet insertion tool. In some embodiments, the sleeve 2724C may be loaded onto a plurality of first magnets (e.g., 2722B) supported by a plurality of first wedges 2710C on a lower tool portion 2704B. In some embodiments, as described herein, the sleeve may be loaded when the expansion mandrel 2706C is in a retracted configuration. For example, the retraction radius 2725C may be a first radius of the sleeve such that the expansion mandrel 2706C can be in a retracted configuration.

[0172] Figure 27D Step 2700D of the apparatus and method for manufacturing a rotor assembly is shown. Some of the disclosed embodiments may involve loading a plurality of second magnets into a magnet insertion tool. For example, magnets from a plurality of second magnets 2726D may be loaded onto a plurality of second wedges 2714D. The wedges 2714D may support the magnets 2726D in the axial direction 2701D (e.g., support the load of the magnets) and / or support the rear of the magnets 2726D. In some embodiments, the plurality of second magnets 2726D may be side magnets. In some embodiments, a sleeve 2724D may be loaded onto the plurality of second magnets 2726D (e.g., the sleeve 2724D may be supported by the plurality of second wedges 2714D). In some embodiments, the plurality of second magnets 2726D may be tapered along the axial direction.

[0173] Figure 27E Step 2700E of the apparatus and method for manufacturing a rotor assembly is shown. In some embodiments, the insertion movement (e.g., a second insertion movement) may involve moving one or more magnets in an axial direction (e.g., axial direction 2701E).

[0174] In some embodiments, the insertion movement may involve moving a magnet among a plurality of first magnets (e.g., 2722B). For example, the insertion movement may involve moving a magnet among a plurality of first magnets and a corresponding plurality of first wedges 2710E in a direction 2731E, which may be the axial direction of the sleeve 2724E. In the example, the plurality of first magnets (in Figure 27E The middle is obscured behind the 2724E sleeve, in Figure 27B The portion 2722B (shown as 2722B) can move axially toward the plurality of second magnets 2726E, while the plurality of second magnets 2726E (and / or the plurality of second wedges 2714E) can remain stationary relative to the sleeve 2724E. In the example, for instance, due to the lower tool portion 2704E being pressed or the support plate 2716E being pressed, the lower tool portion 2704E can move toward the upper tool portion 2702E in the direction 2731E.

[0175] In some embodiments, the insertion movement may involve moving a magnet among a plurality of second magnets (e.g., 2726E). For example, the insertion movement may involve moving a magnet among the plurality of second magnets 2726E and a corresponding plurality of second wedges 2714E in a direction 2733E, which may be the axial direction of the sleeve 2724E. In the example, the plurality of second magnets 2726E may move axially toward a plurality of first magnets (e.g., 2722B, such as behind the sleeve 2724E), while the plurality of first magnets (and / or the plurality of first wedges 2710C) may remain stationary relative to the sleeve 2724E. In the example, for example, due to the upper tool portion 2702E being pressed or the support plate 2720E being pressed, the upper tool portion 2702E may move toward the lower tool portion 2704E in a direction 2733E.

[0176] In some embodiments, the insertion movement may involve moving one of the plurality of second magnets (e.g., 2726E) and the plurality of first magnets, such that the plurality of second magnets move in the axial direction 2733E and the plurality of first magnets move in the direction 2731E (e.g., due to pressing). In the example, at least a portion of the movement of the plurality of first magnets and the movement of both in the axial direction 2731E may occur simultaneously.

[0177] Some disclosed embodiments involve performing an insertion movement (e.g., a first insertion movement) in the radial direction of the sleeve. For example, the movement of an expansion mandrel as described herein (e.g., Figure 27B 2706B in the diagram may cause movement of a plurality of first push rods and / or a plurality of second push rods. In some embodiments, the insertion movement may involve moving a plurality of first magnets in the radial direction 2703E of the sleeve. For example, movement of the expansion mandrel may move a push rod of a plurality of first push rods that can contact a wedge in the first set of wedges, thereby moving a magnet of a plurality of first magnets in the radial direction 2703E. The movement may involve expansion and / or contraction (e.g., retraction) in the radial direction 2703E.

[0178] In some embodiments, the insertion motion may involve moving a plurality of second magnets (e.g., Figure 27D 2726D) in the sleeve moves in the radial direction 2703E. For example, movement of the expansion mandrel can move a push rod among a plurality of second push rods that can contact the wedges in the second set of wedges, thereby causing a magnet among a plurality of second magnets to move in the radial direction 2703E of the sleeve 2724E. Movement can involve expansion and / or contraction (e.g., retraction) in the radial direction 2703E.

[0179] In some embodiments, the insertion motion may involve moving both the plurality of first magnets and the plurality of second magnets in a radial direction.

[0180] Figure 27F Step 2700F of an apparatus and method for manufacturing a rotor assembly is shown. In some embodiments, the insertion movement may involve sliding a plurality of second magnets 2722F in an axial direction 2701F to align with a plurality of first magnets 2722F and a sleeve. For example, a plurality of second magnets 2726F may be axially oriented toward a plurality of first magnets 2722F such that the plurality of second magnets 2726F and the plurality of first magnets 2722F can be aligned (e.g., aligned along the inner diameter of the sleeve (not shown)). In an example where the magnets are tapered in the axial direction, this axial insertion may displace adjacent magnets (e.g., adjacent conical surfaces), thereby causing the sleeve to expand in the radial direction 2703F and generate a preload within the sleeve. In some embodiments, the insertion movement may involve expanding the sleeve by pressing the plurality of magnets against the sleeve in the radial direction 2703F. This movement may also cause the sleeve to expand in the radial direction 2703F and generate a preload. In some embodiments, at least a portion of the insertion movement in the radial direction and the insertion movement in the axial direction may be performed simultaneously.

[0181] In some embodiments, the magnet ring may be a plurality of aligned first magnets 2722F and a plurality of second magnets 2726F. In some embodiments, the magnet insertion tool may involve a hard stop. For example, according to the desired axial alignment of the magnets (e.g., reducing unnecessary movement of the magnets in the axial direction 2701F), the upper support 2734F of the upper tool portion 2702F may be aligned and contacted with the lower support 2736F of the lower tool portion 2704F. In some embodiments, during the insertion movement, the plurality of first magnets 2722F and the plurality of second magnets 2726F may move in the radial direction 2703F. It is understood that the hard stop can prevent excessive expansion of the sleeve, thereby reducing the occurrence of sleeve bursting.

[0182] Figure 27GStep 2700G of an apparatus and method for manufacturing a rotor assembly is illustrated. In some embodiments, manufacturing the rotor assembly may involve expanding a sleeve, as described herein. For example, insertion movements in the axial direction 2701G and radial direction 2703G may involve movement of a plurality of first magnets and / or a plurality of second magnets to expand the sleeve in the radial direction 2703G. An expanded sleeve 2738G may accommodate a magnet ring consisting of a plurality of first magnets and a plurality of second magnets along its inner diameter. In some embodiments, the sleeve may expand from a retraction radius 2725C to a second radius greater than the retraction radius 2725C and greater than the expansion radius 2741G (e.g., the expansion radius may be a third radius greater than the retraction radius 2725C and less than the second radius). For example, the expansion radius 2741G may correspond to the operating radius of the expanded sleeve 2738G, and the sleeve may expand beyond the operating radius (e.g., to maximize magnet preload and alignment). In some embodiments, the expansion radius 2741G may be at least 98% of the second radius. In the example, by removing the upper tool portion 2702G from the lower tool portion 2704G, the sleeve radius can be contracted from the second radius to the expansion radius 2741G, and contraction to the expansion radius 2741G can lock the magnet within the expansion sleeve 2738G. In some embodiments, the sleeve can expand from the retraction radius 2725C to the expansion radius 2741G (e.g., the operating radius).

[0183] Figures 28A-28B A cross-sectional view of a magnet insertion tool consistent with an embodiment of this disclosure is shown. Figure 28A A cross-sectional view of the magnet insertion tool 2800A before expansion (cut through the plurality of first magnet wedges) can be shown. As described herein, the magnet insertion tool 2800A may include a plurality of first push rods 2808A corresponding to the plurality of first wedges 2810A, and a plurality of second push rods (covered by push rods 2808A) corresponding to the plurality of second wedges 2814A. The plurality of first wedges 2810A may support a plurality of first magnets 2822A, and the plurality of second wedges 2814A may support a plurality of second magnets 2826A. A sleeve 2824A may be mounted on the plurality of first magnets 2822A and may have an unexpanded (e.g., contracted) radius 2825A. In some embodiments, the plurality of first magnets 2822A may include pole magnets, and the plurality of second magnets 2826A may include side magnets. In some embodiments, the magnet insertion tool may include a push rod guide plate 2850A.

[0184] As described herein, the magnet insertion tool 2800A may include one or more conical members that can assist in insertion movement. In some embodiments, the magnet insertion tool 2800A may include a single conical member, and a push rod may have a conical surface corresponding to the conical member. In some embodiments, the magnet insertion tool 2800A may include a first conical member 2840A and a second conical member 2842A. For example, a plurality of first push rods 2808A (and similarly a plurality of second push rods) may include a first conical surface 2844A and a second conical surface 2846A, such that the first conical surface 2844A can engage with and move along the conical surface of the first conical member 2840A, and the second conical surface 2846A can engage with and move along the conical surface of the second conical member 2842A.

[0185] In some embodiments, the first insertion movement can be performed with the magnet insertion tool 2800A by moving a plurality of first magnets 2822A or a plurality of second magnets 2826A in the radial direction 2803A. For example, the magnet insertion tool 2800A can be pressed (e.g., from the top, from the bottom, or from both the top and bottom, as described herein, by pressing the support plate) to move the expansion mandrel in the axial direction 2801A of the sleeve 2824A. The conical surfaces of the first conical member 2840A and the second conical member 2842A can act on the first conical surface 2844A and the second conical surface 2846A of the push rod, thereby moving the wedge and thus the magnet in the outward radial direction 2803A. In some embodiments, the guide plate 2850A can move the push rod in the radial direction 2803A (e.g., the push rod can slide along the guide plate) as the guide plate 2850A moves in the axial direction 2801A. A plurality of first magnets 2822A may press against and contact sleeve 2824A, thereby causing sleeve 2824A to expand in the radial direction 2803A. In some embodiments, a second insertion movement may involve sliding a plurality of second magnets 2826A to align with both the plurality of first magnets 2822A and sleeve 2824A. In the example of a conical magnet, contact of the conical surface of the magnet may cause the radius of sleeve 2824A to expand in the radial direction 2803A. Therefore, it is understood that a first insertion movement, a second insertion movement, or both of the first and second insertion movements may cause the radius of sleeve 2824A to expand. In some embodiments, the first insertion movement may occur before the second insertion movement. In some embodiments, the second insertion movement may occur before the first insertion movement. It is understood that the first and second insertion movements may reduce bending and micro-torsion of the sleeve. Some disclosed embodiments may involve performing at least a portion of the first and second insertion movements simultaneously. It is understood that performing at least a portion of the first and second insertion movements simultaneously may reduce magnet damage and bending moments on the magnets. In some examples, the plurality of first magnets 2822A may be pole magnets, and the plurality of second magnets 2826A may be side magnets. It is understood that, in the examples, the pole magnets may be larger than the side magnets (e.g., with a larger surface area), so that the pole magnets can provide frictional force to support the sleeve 2824A, while the side magnets (with a smaller coefficient of friction) move axially toward the sleeve 2824A, thereby supporting the sleeve and reducing kinking and other degradation of the sleeve.

[0186] Figure 28BA cross-sectional view of the magnet insertion tool 2800B in an expanded configuration (cut through multiple first magnet wedges) can be shown. For example, a first conical member 2840B can engage with a first cone 2844B of a push rod 2808B, and a second conical member 2842B can engage with a second cone 2846B. An expansion sleeve 2838B can accommodate a magnet ring 2852B comprising multiple axially aligned first magnets and multiple second magnets, and the expansion sleeve 2838B can expand to an expansion radius 2841B greater than the unexpanded radius 2825A, thereby providing a preload to retain the magnets within the magnet ring 2852B.

[0187] Figure 29 A view of a magnet insertion tool 2900 consistent with embodiments of the present disclosure is shown. For example, magnet insertion tool 2900 may refer to the lower portion of a magnet insertion tool as described herein. In some embodiments, the magnet insertion tool may include a support ring 2902 for supporting magnets and / or magnet wedges in axial and / or radial directions. For example, the support ring may support a plurality of first magnets, a plurality of first magnet wedges, and / or a plurality of second magnet wedges. The support ring may also support a sleeve. For example, a strut 2912 extending from the support ring 2902 may provide circumferential support and alignment for a plurality of first magnets 2904 and a plurality of first magnet wedges 2906. The surface of the strut 2912 may also contact (e.g., rest on) the surfaces of a plurality of second magnet wedges (e.g., when a plurality of second magnet wedges, not shown, may move toward a plurality of first magnet wedges). In some examples, a shoulder 2910 may provide support and alignment for a sleeve. For example, the surface 2914 of the shoulder 2910 may support the sleeve during manufacturing. The support ring 2902 can extend from the support base and can be spring-loaded by the spring 2908. Therefore, it can be understood that the height of the sleeve can be set by adjusting the support ring 2902 (e.g., by the spring 2908).

[0188] Figure 30A view of a magnet insertion tool 3000 consistent with embodiments of the present disclosure is shown. For example, the magnet insertion tool 3000 may refer to the upper tool portion of a magnet insertion tool as described herein. In some embodiments, the magnet insertion tool 3000 may include a support ring 3002 extending from a support plate 3004. For example, the support ring 3002 may be connected to the support plate 3004 by screws. The support ring may be configured to move, for example, to expand and contract (e.g., in the axial direction of a sleeve). The support ring 3002 may be compressed (e.g., using a spring 3006), and a magnet 3010 may be loaded into a magnet wedge 3008 (e.g., a plurality of second magnets may be loaded into a plurality of second wedges). In some embodiments, the support ring 3002 may support and / or retain the magnet wedge 3008. For example, the support ring may be released (e.g., when the spring 3006 expands), and the magnet 3010 and / or the magnet wedge 3008 may be securely in place. In the example, to remove the rotor (e.g., the magnet ring) from the magnet wedge, the support ring 3002 can be compressed. As described herein, in some examples, the magnet wedge 3008 can be held and / or supported by a pin and / or a slot on the support plate 3004. For example, the magnet wedge 3008 may include a pin extending through the magnet wedge, and the slot in the support plate 3004 may be configured to allow radial expansion and contraction movement of the pin and / or the magnet wedge 3008.

[0189] Figure 31 A flowchart of a method 3100 for manufacturing a rotor assembly of an electric motor, consistent with embodiments of the present disclosure, is shown. In some embodiments, method 3100 may include a step 3102 of loading a plurality of first magnets into a magnet insertion tool. For example, the magnet insertion tool may include an expansion mandrel. In some examples, the plurality of first magnets may be conical. In some examples, the plurality of first magnets may be rectangular.

[0190] In some embodiments, method 3100 may include step 3104 of loading a plurality of second magnets into a magnet insertion tool. The plurality of first magnets and the plurality of second magnets may be shaped to form a magnet ring for a rotor assembly. For example, the magnet ring may comprise conical magnets and / or non-conical magnets. In the example of conical magnets, the conical surfaces of the plurality of first magnets may be complementary to the conical surfaces of the plurality of second magnets. In some examples, the magnet ring may comprise a non-magnetic material.

[0191] In some embodiments, method 3100 may include step 3106 of inserting a sleeve into a magnet insertion tool. As an example, the sleeve may be a sleeve configured to be stretchable, such as a sleeve made of carbon fiber as described herein.

[0192] In some embodiments, method 3100 may include step 3108 of performing a first insertion movement using a magnet insertion tool. In some embodiments, the first insertion movement may include moving one of a plurality of first magnets or a plurality of second magnets in a radial direction of the sleeve. In some examples, the first insertion movement may involve moving both the plurality of first magnets and the plurality of second magnets. In some examples, the first insertion movement may involve expanding the sleeve by pressing the plurality of first magnets against the sleeve in a radial direction.

[0193] In some embodiments, one or more magnets may be aligned radially behind another plurality of magnets (e.g., in the radial direction, the plurality of second magnets may initially be arranged closer to the center of the expansion mandrel than the plurality of first magnets). The plurality of first magnets may contact the sleeve and may be pushed radially outward, thereby causing the sleeve to expand radially. If the radial expansion is large enough, the plurality of second magnets can be directly inserted into the gap between the plurality of first magnets without any set of magnets sliding in the axial direction. Therefore, some disclosed embodiments may not require axial insertion movement or tapered magnet surfaces. Alternatively, in some embodiments, if the radial expansion of the sleeve is large enough, the plurality of second magnets can be directly inserted into the gap between the plurality of second magnets. Therefore, in some embodiments, magnets can be assembled without the need for radial movement or tapered magnet surfaces.

[0194] In some embodiments, method 3100 may include step 3110 of performing a second insertion movement using a magnet insertion tool. In some embodiments, the second insertion movement may include moving one of a plurality of first magnets or a plurality of second magnets relative to the sleeve in an axial direction. In some examples, during the second insertion movement, one of the plurality of first magnets or a plurality of second magnets may remain stationary relative to the sleeve in an axial direction. In some examples, the second insertion movement may include sliding the plurality of second magnets in an axial direction to align with both the plurality of first magnets and the sleeve.

[0195] In some embodiments, a plurality of first magnets in contact with the sleeve may expand in the radial direction, and a plurality of second magnets may be inserted axially. For example, the axial movement of the plurality of second magnets may occur after the radial expansion of the plurality of first magnets.

[0196] In some embodiments, method 3100 may include step 3112, during one of the first insertion movement or the second insertion movement, using a magnet insertion tool to expand the radius of the sleeve in the radial direction. Some disclosed embodiments may involve performing at least a portion of the first insertion movement and the second insertion movement simultaneously.

[0197] The embodiments disclosed herein are intended to be non-limiting. Those skilled in the art will understand that modifications can be made to certain components and their configurations without departing from the scope of the disclosed embodiments. The foregoing description has been presented for illustrative purposes. The description is not exhaustive and does not limit the invention to the precise forms or embodiments disclosed. Modifications and adaptations of the invention will be apparent to those skilled in the art upon consideration of the specification and practice of the disclosed embodiments of the invention. Any order of steps shown in the figures is also considered for illustrative purposes only and is not intended to limit the invention to any particular order. For example, steps may be performed in a different order than illustrated, steps may be performed simultaneously, or steps may be omitted. Therefore, those skilled in the art will understand that these steps may be performed in different orders when implementing the same method.

[0198] The following provisions set forth several non-limiting aspects of this disclosure:

[0199] 1. A rotor assembly, the rotor assembly comprising:

[0200] Sleeve;

[0201] Rotor hub; and

[0202] A plurality of conical magnets are arranged circumferentially around the inner diameter of the sleeve, and the plurality of conical magnets are configured to abut against each other.

[0203] The plurality of conical magnets includes a first group of conical magnets and a second group of conical magnets.

[0204] The axial insertion of the first set of conical magnets relative to the second set of conical magnets is configured to increase the diameter of the sleeve, and

[0205] The rotor hub is configured to hold at least one of the plurality of conical magnets or the sleeve.

[0206] 2. The rotor assembly according to Clause 1, wherein the sleeve is configured to retain the plurality of conical magnets.

[0207] 3. The rotor assembly according to clause 1 or 2, wherein the sleeve comprises carbon fiber.

[0208] 4. The rotor assembly according to any one of clauses 1 to 3, further comprising a core.

[0209] 5. The rotor assembly according to Clause 4, wherein the core includes at least one notch configured to mate the core with the rotor hub.

[0210] 6. The rotor assembly according to Clause 4 or 5, further comprising a first rotor hub abutting against a first side of the core and a second rotor hub abutting against a second side of the core opposite to the first side.

[0211] 7. The rotor assembly according to any one of clauses 4 to 6, further comprising at least one cavity disposed between the plurality of conical magnets and the core, wherein the at least one cavity is configured to guide fluid for cooling the magnets in the plurality of conical magnets.

[0212] 8. The rotor assembly according to Clause 7, wherein the core or the at least one cavity is configured to deliver the fluid for direct cooling of the plurality of conical magnets.

[0213] 9. An electric propulsion system for a vertical takeoff and landing (VTOL) aircraft, the electric propulsion system comprising:

[0214] At least one electric engine directly or indirectly mechanically connected to the fuselage of the VTOL aircraft, the electric engine comprising:

[0215] Gearbox assembly, the gearbox assembly comprising:

[0216] Sun gear; and

[0217] An electric motor having a stator and a rotor assembly according to any one of clauses 1 to 8.

[0218] 10. The system according to Clause 9, wherein the gearbox includes a bearing, wherein the outer diameter of the bearing contacts the inner diameter of the sun gear.

[0219] 11. A method for assembling a rotor assembly, the method comprising:

[0220] A plurality of first conical magnets and a plurality of second conical magnets are inserted into each other from opposite directions such that each of the plurality of second conical magnets is located between adjacent pairs of first conical magnets, and the plurality of first conical magnets and the plurality of second conical magnets are arranged to form a magnet ring at the inner surface of the stretchable sleeve.

[0221] 12. The method according to Clause 11, wherein inserting the plurality of first conical magnets and the plurality of second conical magnets comprises increasing the diameter of the stretchable sleeve.

[0222] 13. The method according to Clause 11 or 12 further includes inserting a bearing into the sun gear and attaching the sun gear to at least one of the rotor hubs.

[0223] 14. The method according to any one of clauses 11 to 13 further includes balancing the rotor assembly.

[0224] 15. The method according to any one of clauses 11 to 14, wherein at least one of the rotor hubs holds at least one of the magnet ring or the stretchable sleeve.

[0225] 16. A method for manufacturing a rotor assembly of an electric motor, the method comprising:

[0226] Load multiple first magnets into the magnet insertion tool;

[0227] A plurality of second magnets are inserted into the magnet insertion tool, wherein the shapes of the plurality of first magnets and the plurality of second magnets are designed to form a magnet ring for the rotor assembly;

[0228] Insert the sleeve into the magnet insertion tool;

[0229] Perform a first insertion motion using the magnet insertion tool, wherein the first insertion motion includes moving one of the plurality of first magnets or the plurality of second magnets in the radial direction of the sleeve;

[0230] Performing a second insertion motion using the magnet insertion tool, wherein the second insertion motion includes moving one of the plurality of first magnets or the plurality of second magnets relative to the sleeve in the axial direction of the sleeve; and

[0231] During either the first insertion movement or the second insertion movement, the radius of the sleeve is expanded in the radial direction using the magnet insertion tool.

[0232] 17. The method described in Clause 16 further includes:

[0233] At least a portion of the first insertion motion and the second insertion motion are performed simultaneously.

[0234] 18. The method according to clause 16 or 17, wherein during the second insertion movement, one of the plurality of first magnets or the plurality of second magnets remains stationary relative to the sleeve in the axial direction.

[0235] 19. The method according to any one of Clauses 16 to 18, further comprising:

[0236] During the first insertion movement, both the plurality of first magnets and the plurality of second magnets are moved in the radial direction.

[0237] 20. The method according to any one of clauses 16 to 19, wherein:

[0238] The first insertion movement includes expanding the sleeve by pressing the plurality of first magnets against the sleeve in the radial direction.

[0239] 21. The method according to any one of clauses 16 to 20, wherein:

[0240] The second insertion movement includes sliding the plurality of second magnets in the axial direction to align them with both the plurality of first magnets and the sleeve.

[0241] 22. The method according to Clause 16, wherein expanding the radius of the sleeve comprises expanding the radius from a first radius to a second radius, the method further comprising:

[0242] The radius of the sleeve is reduced from the second radius to a third radius, the third radius being greater than the first radius and less than the second radius.

[0243] 23. The method according to Clause 22, wherein the third radius is at least 98% of the second radius.

[0244] 24. The method according to any one of clauses 16 to 23, wherein the plurality of first magnets and the plurality of second magnets are tapered along the axial direction.

[0245] 25. The method according to any one of claims 16 to 24, wherein the plurality of first magnets and the plurality of second magnets are respectively supported on a plurality of first magnet wedges and a plurality of second magnet wedges of the magnet insertion tool, the method further comprising:

[0246] During the first insertion movement, the plurality of first magnets, the plurality of first magnet wedges, the plurality of second magnets and the plurality of second magnet wedges are moved in the radial direction using the expansion mandrel of the magnet insertion tool.

[0247] 26. The method according to Clause 25, wherein the expanded mandrel comprises:

[0248] A plurality of first push rods, the plurality of first push rods being configured to push the plurality of first magnet wedges; and

[0249] A plurality of second push rods are configured to push the plurality of second magnet wedges.

[0250] 27. The method described in accordance with Clause 26 further includes:

[0251] The magnet insertion tool is used to slide the plurality of first magnet wedges relative to the surfaces of the plurality of first push rods.

[0252] 28. The method described pursuant to Clause 25 or 26, further comprising:

[0253] The magnet insertion tool is used to slide the plurality of second magnet wedges relative to the surfaces of the plurality of second push rods.

[0254] 29. The method according to any one of clauses 25 to 28, wherein the expansion mandrel includes a push rod guide plate configured to guide the plurality of first push rods and the plurality of second push rods in the radial direction.

[0255] 30. The method according to Clause 29, wherein the expansion mandrel includes an alignment shaft configured to align the push rod guide plate in the axial direction when the push rod guide plate guides the plurality of first push rods and the plurality of second push rods in the radial direction.

[0256] 31. The method according to any one of clauses 25 to 30, wherein the magnet insertion tool comprises a first support plate configured to support the plurality of first magnet wedges and a second support plate configured to support the plurality of second magnet wedges.

[0257] The method further includes:

[0258] Move the plurality of first magnet wedges relative to the first support plate in the radial direction; and

[0259] The plurality of second magnet wedges are moved relative to the second support plate in the radial direction.

[0260] 32. The method described in accordance with Clause 31 further includes:

[0261] During the first insertion movement and the second insertion movement, the second support plate is pressed against the first support plate in the axial direction.

[0262] 33. The method according to clause 31 or 32, wherein moving the plurality of first magnet wedges relative to the first support plate in the radial direction includes moving the plurality of first magnet wedges in a plurality of first slots in the first support plate.

[0263] 34. The method according to any one of clauses 31 to 33, wherein moving the plurality of second magnet wedges relative to the second support plate in the radial direction comprises moving the plurality of second magnet wedges in a plurality of second slots in the second support plate.

[0264] 35. A vertical takeoff and landing (VTOL) aircraft, the VTOL aircraft comprising an electric propulsion system as described in Clause 9 or 10.

Claims

1. A method for manufacturing a rotor assembly of an electric motor, the method comprising: Load multiple first magnets into the magnet insertion tool; Multiple second magnets are inserted into the magnet insertion tool. The shapes of the plurality of first magnets and the plurality of second magnets are designed to form a magnet ring for the rotor assembly; Insert the sleeve into the magnet insertion tool; The magnet insertion tool is used to perform an insertion movement of the plurality of first magnets relative to the plurality of second magnets, wherein the insertion movement includes: The plurality of first magnets are moved in the radial direction of the sleeve; To move the plurality of second magnets in the axial direction of the sleeve; and During the insertion movement, the radius of the sleeve is expanded in the radial direction using the magnet insertion tool.

2. The method according to claim 1, further comprising: Simultaneously, the plurality of first magnets are moved in the radial direction and the plurality of second magnets are moved in the axial direction.

3. The method of claim 1, wherein during the insertion movement, the plurality of first magnets remain stationary relative to the sleeve in the axial direction.

4. The method according to claim 1, further comprising: During the insertion movement, the plurality of second magnets are moved in both the axial direction and the radial direction.

5. The method of claim 1, wherein the insertion motion further comprises: The sleeve is expanded by pressing the plurality of first magnets against the sleeve in the radial direction.

6. The method of claim 1, wherein the insertion motion further comprises: The plurality of second magnets are slid in the axial direction to align with both the plurality of first magnets and the sleeve in the axial direction.

7. The method of claim 1, wherein expanding the radius of the sleeve comprises expanding the radius from a first radius to a second radius, the method further comprising: The radius of the sleeve is reduced from the second radius to a third radius, the third radius being greater than the first radius and less than the second radius.

8. The method of claim 7, wherein the third radius is at least 98% of the second radius.

9. The method according to claim 1, wherein the plurality of first magnets and the plurality of second magnets are tapered along the axial direction.

10. The method of claim 1, wherein the plurality of first magnets and the plurality of second magnets are respectively supported on the plurality of first magnet wedges and the plurality of second magnet wedges of the magnet insertion tool, the method further comprising: During the insertion movement, the plurality of first magnets, the plurality of first magnet wedges, the plurality of second magnets and the plurality of second magnet wedges are moved in the radial direction using the expansion mandrel of the magnet insertion tool.

11. The method of claim 10, wherein the expanded mandrel comprises: A plurality of first push rods, the plurality of first push rods being configured to push the plurality of first magnetic wedges; as well as A plurality of second push rods are configured to push the plurality of second magnet wedges.

12. The method of claim 11, further comprising: The magnet insertion tool is used to slide the plurality of first magnet wedges relative to the surfaces of the plurality of first push rods.

13. The method of claim 11, further comprising: The magnet insertion tool is used to slide the plurality of second magnet wedges relative to the surfaces of the plurality of second push rods.

14. The method of claim 11, wherein the expanded mandrel comprises: A push rod guide plate is configured to guide the plurality of first push rods and the plurality of second push rods in the radial direction.

15. The method of claim 14, wherein the expanded mandrel comprises: An alignment axis is configured to align the push rod guide plate in the axial direction when the push rod guide plate guides the plurality of first push rods and the plurality of second push rods in the radial direction.

16. The method of claim 10, wherein the magnet insertion tool comprises a first support plate configured to support the plurality of first magnet wedges and a second support plate configured to support the plurality of second magnet wedges, the method further comprising: The plurality of first magnet wedges are moved relative to the first support plate in the radial direction; And to move the plurality of second magnet wedges relative to the second support plate in the radial direction.

17. The method of claim 16, further comprising: During the insertion movement, the second support plate is pressed against the first support plate in the axial direction.

18. The method of claim 16, wherein moving the plurality of first magnet wedges relative to the first support plate in the radial direction comprises moving the plurality of first magnet wedges in a plurality of first slots in the first support plate.

19. The method of claim 16, wherein moving the plurality of second magnet wedges relative to the second support plate in the radial direction comprises moving the plurality of second magnet wedges in a plurality of second slots in the second support plate.

20. The method of claim 10, wherein the plurality of first magnet wedges and the plurality of second magnet wedges are respectively supported by a plurality of locking mechanisms for the plurality of first magnets and the plurality of second magnets.

21. The method of claim 20, wherein the plurality of locking mechanisms further comprises a plurality of pins.

22. The method of claim 1, wherein the magnet ring further comprises a non-magnetic material.

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