System, method, and mechanical design for EVTOL aircraft inverters

Abstract

An electric propulsion system for a vertical take-off and landing (VTOL) aircraft comprises an electric motor assembly and an inverter assembly. The inverter assembly comprises a housing, a capacitor assembly, at least one printed circuit board assembly (PCBA), and a plurality of positioning pins. The capacitor assembly comprises a center hole, at least one capacitor, a capacitor housing having at least one busbar, and a plurality of through holes in the capacitor housing. The capacitor assembly and at least one PCBA are located within the housing. The plurality of positioning pins pass through the plurality of through holes in the capacitor housing and at least one PCBA and are connected to the housing.

Description

Technology Field

[0001] This disclosure claims priority to U.S. Patent Application No. 18 / 306,275, filed April 25, 2023, titled “System, method and mechanical design for an inverter for an EVTOL aircraft,” which in turn claims priority to U.S. Provisional Application No. 63 / 378,536, filed October 6, 2022, titled “Tilt rotor system and method for an eVTOL aircraft,” and U.S. Provisional Application No. 63 / 378,680, filed October 7, 2022, titled “System and method for an improved propulsion system for an eVTOL aircraft.” The contents of the aforementioned applications are incorporated herein by reference in their entirety for all purposes.

[0002] The present disclosure generally relates to the field of powered aircraft. More specifically, and without limitation, the present disclosure relates to innovations in aircraft driven by electric propulsion systems. Specific aspects of the present disclosure generally relate to improvements in electric engines, gearboxes, and power inverters that provide specific advantages to aircraft and other types of transport vehicles driven by electric propulsion systems.

[0003] This disclosure relates to systems, components, and techniques intended for primary use in unconventional aircraft driven by electric propulsion systems. For example, the tilt-rotor aircraft of this disclosure may be configured to perform frequent (e.g., more than 50 flights per workday) and short flights (e.g., less than 100 miles per flight) over and in and out of densely populated areas. The aircraft may be configured to transport 4 to 6 passengers or commuters who expect a low-noise and low-vibration experience. Accordingly, the components of the aircraft are configured and designed to withstand frequent use without wear and tear and to generate less heat and vibration, and it may be desirable for the aircraft to include mechanisms for effectively controlling and managing the heat or vibration generated by the components. Additionally, multiple such aircraft may be intended to operate in close proximity to each other in congested metropolitan areas. Accordingly, it may be desirable for the components to be configured and designed to generate low levels of noise both inside and outside the aircraft and to have various safety and backup mechanisms. For example, for safety reasons, it may be desirable for an aircraft to be propelled by a distributed propulsion system to avoid the risk of a single point of failure and to enable normal takeoffs and landings on a runway. Additionally, it may be desirable for the aircraft to safely take off and land vertically in relatively small and confined spaces compared to traditional airport runways (e.g., vertical takeoff and landing airfields, parking lots, or roadways), while transporting multiple passengers or commuters along with baggage. These usage requirements may impose design constraints on aircraft size, weight, and operational efficiency (e.g., drag, energy consumption), which can affect the design and configuration of aircraft components.

[0004] The disclosed embodiments provide new and improved configurations of aircraft components not typically observed in aircraft and / or identified design criteria for components different from those of conventional aircraft. These alternative configurations and design criteria have generated the embodiments disclosed herein for various configurations and designs of components for aircraft driven by electric propulsion systems, while addressing the disadvantages and challenges of conventional components.

[0005] In some embodiments, an aircraft driven by the electric propulsion system of the present disclosure may be designed to enable vertical and conventional take-off and landing as a distributed electric propulsion system capable of vertical flight, horizontal and lateral flight, and switching. Thrust may be generated by supplying high-voltage power to a plurality of electric engines of the distributed electric propulsion system, which may include components necessary to convert high-voltage power into mechanical shaft power to rotate propellers. Embodiments disclosed herein may include steps for optimizing the energy density of the electric propulsion system. Embodiments may include electric engines connected to an onboard power source, which may include devices capable of storing energy such as batteries or capacitors, or one or more systems for utilizing or generating electricity such as fuel-driven generators or solar panel arrays. Some disclosed embodiments enable conversion from direct current (DC) to alternating current (AC) by an inverter assembly to allow for more powerful AC motors. Some disclosed embodiments reduce the weight and space of components within the aircraft to increase aircraft efficiency and performance. The disclosed embodiments also improve the safety of passenger transport by using new and improved safety protocols and system redundancy in the event of failure to minimize any single point of failure in the aircraft propulsion system. Some disclosed embodiments also provide new and improved approaches to satisfy and exceed aviation and transportation laws and regulations. For example, the Federal Aviation Administration enforces federal laws and regulations that require safety components, such as fire barriers adjacent to engines using more than a critical amount of oil or other flammable materials.A fire barrier may include engine components or aircraft components designed, constructed, or installed for the primary purpose of preventing harmful amounts of air, fluid, or flame from passing around or through the fire barrier and / or protecting it from corrosion. In some embodiments, the fire barrier may include additional components and separate components as incorporated herein. Those skilled in the art will understand that any component within the aircraft, including an electric propulsion system, will function as a fire barrier. In some embodiments, the fire barrier may include a fire wall, a non-combustible barrier, a fireproof barrier, a flame-retardant barrier, or any other barrier capable of ensuring that harmful amounts of air, fluid, or flame cannot pass around or through the barrier and / or protect it from corrosion. For example, a gas may be constructed to prevent harmful amounts of air, fluid, or flame from passing around or through the fire barrier and / or protecting it from corrosion, whereas the gas may not be considered a fire barrier because the primary purpose of the gas is not a fire barrier. In some embodiments, the electric propulsion system uses oil below a critical level to provide efficient and effective lubrication and cooling, thereby eliminating the need for engine fire barriers and creating an aircraft that maximizes performance and efficiency while reducing aircraft weight.

[0006] In some embodiments, the distributed electric propulsion system may include 12 electric engines that can be mounted on the forward and rear booms of the aircraft's main wings. Some of the electric engines, such as those mounted on the forward of the main wings, may be tilted during flight between a horizontally oriented position (e.g., to generate forward thrust for cruising) and a vertically oriented position (e.g., to generate vertical lift for takeoff, landing, and hovering). The propellers of the forward electric engines may rotate clockwise or counterclockwise. The propellers may rotate in the opposite direction relative to adjacent propellers. The rear electric engines may be fixed in a vertically oriented position (e.g., to generate vertical lift). The propellers may also rotate clockwise or counterclockwise. In some embodiments, the difference in rotation direction may be achieved using the engine rotation direction. In other embodiments, the engines may all rotate in the same direction, and gearing may be used to achieve different propeller rotation directions.

[0007] In some embodiments, the aircraft may have multiple electric engines in various combinations of forward and rear engine configurations. For example, the aircraft may have any other combinations of forward and rear engines, including six forward electric engines and six rear electric engines, four forward electric engines and four rear electric engines, or embodiments in which the number of forward electric engines and rear electric engines is not equal.

[0008] In a preferred embodiment, for a vertical take-off and landing (VTOL) mission, the forward and rear electric engines can provide vertical thrust during take-off and landing. During the flight phase in which the aircraft moves forward, the forward electric engine can provide horizontal thrust, while the propeller of the rear electric engine can be retracted in a fixed position to minimize drag. The rear electric engine can be actively retracted via position monitoring. The transition from vertical flight to horizontal flight or vice versa can be performed via a tilt propeller subsystem. The tilt propeller subsystem can change thrust between the vertical direction, primarily during the vertical flight mode, and the horizontal or near-horizontal direction during the forward flight cruising phase. A variable pitch mechanism can change the angle of the propeller-hub assembly blade collective of the forward electric engine for operation during the hovering phase, the transition phase, and the cruising phase.

[0009] In some embodiments, during conventional take-off and landing (CTOL) missions, the forward electric engine may provide horizontal thrust for wing-based take-off, cruising, and landing, and the wings may provide vertical lift. In some embodiments, the rear electric engine may not be used to generate thrust during CTOL missions, and the rear propeller may be stowed in place. In other embodiments, the rear electric engine may be used at reduced power to shorten the length of the CTOL take-off and landing.

[0010] In some embodiments, an inverter assembly for converting direct current (DC) power to alternating current (AC) power for an electric propulsion system may include a housing, a capacitor assembly, at least one printed circuit board assembly (PCBA), and a plurality of positioning pins. In some embodiments, the capacitor assembly may have a center hole, at least one capacitor, a capacitor housing having at least one busbar, and a plurality of through holes in the capacitor housing. In some embodiments, the capacitor assembly and at least one PCBA are located within the housing. In some embodiments, a plurality of positioning pins pass through a plurality of through holes in the capacitor housing and at least one PCBA and are connected to the housing.

[0011] In some embodiments, the electric engine for a vertical take-off and landing aircraft may include or be connected to an inverter assembly. In some embodiments, the centerline of the inverter assembly may be aligned with the main shaft of the electric engine. In some embodiments, airflow driven by the electric engine may cool the inverter assembly to manage the operating temperature and optimize the performance of the inverter assembly.

[0012] In some embodiments, the inverter assembly may have a housing having a circular shape or other shapes designed to minimize drag during flight. Additionally, the inverter assembly may be installed such that the housing shape minimizes drag under different flight conditions. Brief explanation of the drawing

[0013] The patent or application file includes at least one drawing in color. A copy of the patent or patent application publication containing the color drawing(s) will be provided by the Patent Office upon request and payment of the necessary fees. Fig. 1 is a perspective view of an exemplary VTOL aircraft according to a disclosed embodiment. Fig. 2This is another illustration of a perspective view of an example VTOL aircraft of an alternative configuration according to an embodiment of the present disclosure. Fig. 3 [Image] is a top plan view of an exemplary VTOL aircraft according to an embodiment of the present disclosure. Fig. 4 is a schematic diagram illustrating the rotation of an exemplary propeller of a VTOL aircraft according to a disclosed embodiment. Fig. 5 is a schematic diagram illustrating an exemplary power connection of a VTOL aircraft according to a disclosed embodiment. Fig. 6 is a block diagram illustrating an exemplary structure and design of an electric propulsion unit of a VTOL aircraft according to a disclosed embodiment. Fig. 7 is a schematic diagram illustrating an exemplary tilt electric propulsion system of a VTOL aircraft according to a disclosed embodiment. Figs. 8a-8c is in the disclosed embodiment According to This is a diagram of an example tilt electric propulsion system for a VTOL aircraft. Fig. 9 is a schematic diagram illustrating an exemplary lift electric propulsion system of a VTOL aircraft according to a disclosed embodiment. Figs. 10a-10b is a diagram of an exemplary lift electric propulsion system for a VTOL aircraft according to a disclosed embodiment. Figs. 11a-11c is a cross-sectional view of an exemplary electric propulsion system of a VTOL aircraft according to a disclosed embodiment. Figs. 12a-12d is an illustration and block diagram of an exemplary electric propulsion system for a VTOL aircraft according to a disclosed embodiment. Fig. 13 is an illustration of an exploded view of an exemplary electric propulsion system of a VTOL aircraft according to a disclosed embodiment. Fig. 14 is an exploded view of an exemplary electric motor assembly of a VTOL aircraft according to a disclosed embodiment. Figs. 15a-15c is a diagram of a stator assembly of a VTOL aircraft according to a disclosed embodiment. Figs. 16a-16c is an exploded view and cross-sectional view of a rotor assembly of a VTOL aircraft according to a disclosed embodiment. Fig. 17 is an exploded view of a main shaft assembly of a VTOL aircraft according to a disclosed embodiment. Fig. 18is a diagram of an example sun gear of a VTOL aircraft according to a disclosed embodiment. Fig. 19 is a diagram of an exemplary ring gear of a VTOL aircraft according to a disclosed embodiment. Fig. 20 [Image] is a diagram of an exemplary carrier assembly of a VTOL aircraft according to a disclosed embodiment. Figs. 21a-21b is a diagram of an exemplary end bell assembly of a VTOL aircraft according to a disclosed embodiment. Fig. 22 is a diagram of an exemplary inverter assembly of a VTOL aircraft according to a disclosed embodiment. Fig. 23 is an exploded view of an inverter assembly of a VTOL aircraft according to a disclosed embodiment. Fig. 24 is a diagram of an exemplary printed circuit board assembly of a VTOL aircraft according to a disclosed embodiment. Figs. 25a-25c This is an exemplary front view and illustration of a heat exchanger for a VTOL aircraft according to a disclosed embodiment. Fig. 26 is a diagram of a heat exchanger for a VTOL aircraft according to a disclosed embodiment. Figs. 27a-27f is a diagram of a separator plate of a VTOL aircraft according to a disclosed embodiment. Fig. 28 is a diagram of a heating plate of a VTOL aircraft according to a disclosed embodiment. Fig. 29 is a diagram of an electric propulsion system for a VTOL aircraft according to a disclosed embodiment. Figs. 30a-30b is a diagram of an exemplary electric propulsion system for a VTOL aircraft according to a disclosed embodiment. Figs. 31a-31b is a cross-sectional view of an electric propulsion system of a VTOL aircraft according to a disclosed embodiment. Figs. 32a-32d is a cross-sectional view of an electric propulsion system of a VTOL aircraft at various flight stages according to the disclosed embodiment. Figs. 33a-33c is a schematic diagram illustrating an exemplary electric propulsion system of a VTOL aircraft including a fire barrier according to a disclosed embodiment. Figs. 34a-34d is a schematic diagram illustrating an exemplary electric propulsion system of a VTOL aircraft according to a disclosed embodiment. Fig. 35 is a schematic diagram illustrating an exemplary electric propulsion system of a VTOL aircraft according to a disclosed embodiment. Figs. 36a-36b is a schematic diagram illustrating an exemplary electric propulsion system of a VTOL aircraft according to a disclosed embodiment. Fig. 37 is a schematic diagram illustrating an exemplary electric propulsion system of a VTOL aircraft according to a disclosed embodiment. Figs. 38a-38b is a schematic diagram illustrating an exemplary electric propulsion system of a VTOL aircraft and an exemplary inverter assembly of the electric propulsion system according to a disclosed embodiment. Figs. 39a-39d is a cross-sectional, perspective, and schematic view illustrating an exemplary electric propulsion system of a VTOL aircraft according to a disclosed embodiment. Figs. 40a-40d is a diagram and schematic illustration illustrating an electric propulsion system of a VTOL aircraft according to a disclosed embodiment. Fig. 41 is a cross-sectional view of an electric propulsion system of a VTOL aircraft according to a disclosed embodiment. Figs. 42a-42b is a diagram of an exemplary electric propulsion system for a VTOL aircraft according to a disclosed embodiment. Figs. 43a-43d is a diagram and schematic illustration illustrating an exemplary electric propulsion system of a VTOL aircraft according to a disclosed embodiment. Figs. 44a-44c is disclosed Examples This is a schematic diagram illustrating an example electric propulsion system of a VTOL aircraft. Figs. 45a-45d is a schematic diagram illustrating an exemplary electric propulsion system of a VTOL aircraft according to a disclosed embodiment. Figs. 46a-46b is a schematic diagram illustrating an exemplary electric propulsion system of a VTOL aircraft according to a disclosed embodiment. Figs. 47a-47b is a schematic diagram and cross-sectional view of an exemplary electric propulsion system for a VTOL aircraft according to a disclosed embodiment. Fig. 48 is in the disclosed embodiments According to This is a schematic diagram illustrating an example electric propulsion system of a VTOL aircraft. Fig. 49 is a cross-sectional view of an exemplary electric propulsion system of a VTOL aircraft according to a disclosed embodiment. Fig. 50 is a perspective view of an example rotor of a VTOL aircraft according to a disclosed embodiment. Fig. 51is a flowchart of an exemplary process for balancing the rotors of a VTOL aircraft according to a disclosed embodiment. Fig. 52 This is another flowchart of an exemplary process for balancing a rotor assembly of a VTOL aircraft according to a disclosed embodiment. Fig. 53 is a flowchart of an exemplary process for transmitting torque from an electric motor assembly to a propeller assembly of a VTOL aircraft according to a disclosed embodiment. Fig. 54 This is a schematic diagram of an example electric motor assembly in a partial cross-sectional view. Figs. 55a-55b is a diagram of the inner surface of an example rotor hub and an example end plate according to a disclosed embodiment. Fig. 55c This is the simulation result of the air velocity and pressure distribution inside the case according to the disclosed embodiment. Fig. 55d is disclosed line An illustration of the inner surface of an example end plate according to the example is shown. Fig. 56a is a diagram illustrating a cross-sectional view of a press mesh port according to a disclosed embodiment. Fig. 56b This is a diagram illustrating a cross-sectional view of a press-in mesh port after installation when operating in an inclined position according to a disclosed embodiment. Fig. 57 This is a cross-sectional perspective view of an integrated sensor of a switchboard according to a disclosed embodiment. Fig. 58 is a perspective view of a flexible PCBA connection according to a disclosed embodiment. Fig. 59 is a cross-sectional view of a bent connection of a flexible PCBA shown in FIG. 58 according to a disclosed embodiment, showing a partial cut-out. do 60a is a diagram of a capacitor housing showing alignment pins according to a disclosed embodiment. Fig. 60b is according to the disclosed embodiment combination This is a diagram of a heat exchanger and heat plates showing alignment pins. Specific details for implementing the invention

[0014] The disclosed embodiments provide systems, subsystems, and components for a new VTOL aircraft having various combinations of electric propulsion systems and cooling systems that minimize weight while maximizing performance.

[0015] In some embodiments, as described herein, the electric propulsion system may generate thrust by supplying high-voltage (HV) power to an electric engine, which converts the HV power into mechanical shaft power used to rotate the propeller. As described herein, the aircraft may include multiple electric engines mounted forward and aft of the wings. The engines may be mounted directly to the wings or mounted on one or more booms attached to the wings. The amount of thrust generated by each electric engine may be controlled by torque commands from the flight control system (FCS) via a digital communication interface to each electric engine. Embodiments may include a forward electric engine capable of changing direction or tilt. Some embodiments include a forward engine that may be of the clockwise (CW) or counterclockwise (CCW) type. The forward electric propulsion subsystem includes a variable pitch subsystem as well as not It can be composed of a multi-blade adjustable pitch propeller.

[0016] In some embodiments, the aircraft may include a rear electric engine or lifter that may be of a clockwise (CW) or counterclockwise (CCW) type. Some embodiments may include a rear electric engine using a multi-blade fixed-pitch propeller.

[0017] As described in this specification, the orientation and use of the electric propulsion system components may change throughout the operation of the aircraft. In some embodiments, the rear propulsion system as well as the forward propulsion system may provide vertical thrust during vertical takeoff and landing. During the flight phase in which the aircraft is in forward flight mode, the forward propulsion system may provide horizontal thrust, while the rear propulsion system propeller may be retracted in a fixed position to minimize drag. The rear electric propulsion system may be actively retracted via position monitoring. Some embodiments may include the transition from vertical flight to horizontal flight and vice versa. In some embodiments, the transition may be achieved via a tilt propeller system (TPS). The TPS may change the electric propulsion system from a primarily vertical direction during vertical flight mode to a primarily horizontal direction during forward flight mode. Some embodiments may include a variable pitch mechanism capable of changing the angle of the forward propulsion system propeller blade collective for operation during the hovering phase, cruising phase, and transition phase. Some embodiments may include a conventional take-off and landing (CTOL) configuration so that the tilter provides horizontal thrust for wing-based take-off, cruise, and landing phases. In some embodiments, the rear electric engine is not used to generate thrust during CTOL missions, and the rear propeller is stowed in place to minimize drag.

[0018] In some embodiments, as described herein, the electric engine may have design features that protect against and mitigate uncontrolled fire, such as using a non-hazardous amount of combustible fluid contained in both the tilt and lift engines. For example, in some embodiments, the electric engine may be configured to use less than 1 quart of oil or other combustible fluid. Some embodiments may include an electric engine containing a non-hazardous amount of air so that no fire can maintain a duration that is movable to other parts of the aircraft. In some embodiments, the non-hazardous amount of air may come into contact with the combustible fluid throughout the electric engine. Some examples may include an electric engine having up to 1 liter, 2 liters, 3 liters, 4 liters, 5 liters, 10 liters, or 20 liters of air within the electric engine housing. In some embodiments, the amount of air present within the electric engine housing may have a fixed ratio to the oil or other liquid for cooling present within the electric propulsion system. This ratio may be driven by the determination of sufficient thermal capacity required to properly cool the electric propulsion system. Some embodiments may include an air-to-oil ratio of about 3:1 present within the electric propulsion system. Some embodiments may include an electric engine housing in which 75% of the open volume—that is, the internal volume not occupied by the components of the electric engine—is composed of air, while 25% of the open volume is composed of oil or some other liquid for cooling and / or lubrication. Some embodiments may also be configured without a nominal ignition source within the electric engine, have an engine with a temperature operating limit that may be more than 50°C lower than the flammable fluid autoignition point, and have temperature overload detection and protection, overvoltage detection and protection, or overcurrent detection and protection.Additionally, some embodiments may include an electric propulsion system in which the inbound temperature of the electric propulsion system is lower than the autoignition and flash points of the oil or any other liquid present within the electric propulsion system under all normal operating conditions. In some embodiments, abnormal conditions that increase the inbound temperature of the electric propulsion system may result in a system response that prevents exceeding the flash and autoignition points of the oil or other liquid. In some embodiments, if a fire occurs within the electric engine housing, including cases where an arc causes a fire, the ratio of air to oil or other liquid may ensure that the amount of air present within the electric engine housing prevents the fire from spreading to other areas of the aircraft. In some embodiments, these and other design features may create an electric engine that is considered to be one or more guidelines or regulations rather than a designated fire zone.

[0019] We will now refer in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. The following description refers to the accompanying drawings, and in different drawings, the same numbers represent the same or similar elements unless otherwise indicated. The embodiments presented in the following description of exemplary embodiments do not represent all embodiments consistent with the present disclosure. Rather, they are merely examples of devices and methods consistent with aspects related to the subject matter cited in the appended claims.

[0020] A. Example electric aircraft features

[0021] Fig. 1 is a perspective view of an exemplary VTOL aircraft according to a disclosed embodiment. Fig. 2 This is another illustration of a perspective view of an example VTOL aircraft of an alternative configuration according to an embodiment of the present disclosure. Fig. 1 and Fig. 2100, 200 respectively illustrate a VTOL aircraft in a cruising configuration and a vertical take-off and landing and hovering configuration (also referred to as a “lift” configuration in this specification) according to the embodiments disclosed herein. Fig. 1 and Fig. 2 The corresponding element may have a similar number and refer to a similar element of the aircraft (100, 200). The aircraft (100, 200) may include a fuselage (102, 202), wings (104, 204) mounted on the fuselage (102, 202), and one or more rear stabilizers (106, 206) mounted on the rear of the fuselage (102, 202). A plurality of lift propellers (112, 212) may be mounted on the wings (104, 204) and may be configured to provide lift for vertical takeoff, landing, and hovering. A plurality of tilt propellers (114, 214) may be mounted on the wings (104, 204), and Fig. 2 A lift configuration that provides part of the lift required for vertical takeoff, landing, and hovering, as illustrated in [figure], and Fig. 1 As illustrated in [Image], it may be tilted between cruising configurations that provide forward thrust to the aircraft (100) for horizontal flight. As used herein, a tilt propeller lift configuration refers to any tilt propeller direction in which the tilt propeller thrust primarily provides lift to the aircraft, and a tilt propeller cruising configuration refers to any tilt propeller direction in which the tilt propeller thrust primarily provides forward thrust to the aircraft.

[0022] In some embodiments, the lift propeller (112, 212) may be configured to provide only lift, and all horizontal thrust is provided by the tilt propeller. Thus, the lift propeller (112, 212) may be configured in a fixed position and may generate thrust only during the takeoff, landing, and hovering phases of flight. Meanwhile, the tilt propeller (114, 214) may be tilted upward in a lift configuration where thrust from the propeller (114, 214) is directed downward to provide additional lift.

[0023] In the case of forward flight, the tilt propeller (114, 214) can be tilted from a lift configuration to a cruising configuration. In other words, the direction of the tilt propeller (114, 214) can be changed from a direction in which the tilt propeller thrust is directed downward (to provide lift during vertical takeoff, landing, and hovering) to a direction in which the tilt propeller thrust is directed backward (to provide forward thrust to the aircraft (100, 200)). A tilt propeller assembly for a specific electric engine can be tilted around a rotation axis defined by a mounting point connecting the boom and the electric engine. When the aircraft (100, 200) is in full forward flight, lift can be provided entirely by the wings (104, 204). Meanwhile, in the cruising configuration, the lift propeller (112, 212) can be stopped. The blades (120, 220) of the lift propellers (112, 212) can be maintained in a low drag position for aircraft cruising. In some embodiments, the lift propellers (112, 212) are each Fig. 1As exemplified in [Figure], it may have two blades (120, 220) that can be submerged to cruise at a minimum drag position where one blade is immediately ahead of the other. In some embodiments, the lift propeller (112, 212) has more than two blades. In some embodiments, the tilt propeller (114, 214) may include more blades (116, 216) than the lift propeller (112, 212). For example, Fig. 1 and Fig. 2 As illustrated in the figure, the lift propellers (112, 212) may each include, for example, two blades, while the tilt propellers (114, 214) may each include more blades, such as the five blades illustrated. In some embodiments, each of the tilt propellers (114, 214) may have two to five blades, and may have more blades depending on the design considerations and requirements of the aircraft.

[0024] In some embodiments, the aircraft may include a single wing (104, 204) (or a single wing extending over the entire aircraft) on each side of the fuselage (102, 202). At least a portion of the lift propeller (112, 212) may be located at the rear of the wing (104, 204), and at least a portion of the tilt propeller (114, 214) may be located at the front of the wing (104, 204). In some embodiments, all lift propellers (112, 212) may be located at the rear of the wing (104, 204), and all tilt propellers (114, 214) may be located at the front of the wing (104, 204). According to some embodiments, all lift propellers (112, 212) and tilt propellers (114, 214) may be mounted on the wing. That is, the lift propeller or tilt propeller may not be mounted on the fuselage. In some embodiments, the lift propellers (112, 212) may both be located at the rear of the wing (104, 204) and the tilt propellers (114, 214) may both be located at the front of the wing (104, 204). According to some embodiments, all lift propellers (112, 212) and tilt propellers (114, 214) may be located inside the ends of the wing (104, 204).

[0025] In some embodiments, the lift propeller (112, 212) and the tilt propeller (114, 214) may be mounted to the wing (104, 204) by a boom (122, 222). The boom (122, 222) may be mounted below the wing (104, 204), on the top of the wing, and / or integrated into the wing profile. In some embodiments, the lift propeller (112, 212) and the tilt propeller (114, 214) may be mounted directly to the wing (104, 204). In some embodiments, one lift propeller (112, 212) and one tilt propeller (114, 214) may be mounted to each boom (122, 222). The lift propeller (112, 212) may be mounted on the rear end of the boom (122, 222) and the tilt propeller (114, 214) may be mounted on the front end of the boom (122, 222). In some embodiments, the lift propeller (112, 212) may be mounted at a fixed position on the boom (122, 222). In some embodiments, the tilt propeller (114, 214) may be mounted on the front end of the boom (122, 222) via a hinge. A tilt propeller (114, 214) can be mounted on the boom (122, 222) so that when in a cruising configuration, the tilt propeller (114, 214) is aligned with the body of the boom (122, 222) to form a continuous extension of the forward end of the boom (122, 222) that minimizes drag for forward flight.

[0026] In some embodiments, the aircraft (100, 200) may include, for example, a single wing on each side of the 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 on the upper side of the fuselage (102, 202). According to some embodiments, the wing includes control surfaces such as flaps and / or ailerons. According to some embodiments, the wing (104, 204) may be designed with a profile that reduces drag during forward flight. In some embodiments, the wing tip profile may be curved and / or tapered to minimize drag.

[0027] In some embodiments, the rear stabilizer (106, 206) includes a control surface such as one or more rudders, one or more elevators, and / or one or more combined rudder-elevators. The wing(s) may have any suitable design. In some embodiments, the wing has a tapering leading edge.

[0028] In some embodiments, the lift propeller (112, 212) or the tilt propeller (114, 214) may be canted relative to at least one other lift propeller (112, 212) or tilt propeller (114, 214). As used herein, canting refers to the orientation of the axis of rotation of the lift propeller / tilt propeller relative to a line parallel to the fore-and-aft direction, similar to the roll degrees of freedom of the aircraft. Canting of the lift propeller and / or tilt propeller may help minimize damage from propeller rupture and provide improved yaw control during flight by orienting the plane of rotation of the lift propeller / tilt propeller disk (blades and the hub on which the blades are mounted) so as not to intersect with critical parts of the aircraft (fuselage area where a person may be located, critical flight control systems, batteries, adjacent propellers, etc.) or other propeller disks.

[0029] Fig. 3 is a top plan view of an exemplary VTOL aircraft according to an embodiment of the present disclosure. The aircraft (300) shown in the drawing is each Fig. 1 and Fig. 2 The aircraft (100, 200) illustrated in the figure may be a top plan view. As discussed herein, the aircraft (300) may include 12 electric propulsion systems distributed across the aircraft (300). In some embodiments, the distribution of electric propulsion systems may include six forward electric propulsion systems (314) and six rear electric propulsion systems (312) mounted on the forward and rear booms of the main wing (304) of the aircraft (300). In some embodiments, the length of the rear end of the boom (324) from the wing (304) to the lift propeller (312) may include a similar rear end length of the boom (324) over numerous rear ends of the boom. In some embodiments, the length of the rear end of the boom may vary, for example, over six rear ends of the boom. For example, each rear end of the boom (324) may include different lengths from the wing (304) to the lift propeller (312), or a subset of the rear ends of the boom may have similar lengths. In some embodiments, the front end of the boom (322) may include varying lengths from the wing (304) across the front end of the boom to the tilt propeller (314). For example, Fig. 3As illustrated in [Image], the length of the forward end of the boom (322) from the tilt propeller (314) closest to the fuselage to the wing (304) may include a length longer than the length of the forward end of the boom (322) from the wing (304) to the tilt propeller (314) furthest from the fuselage. Some embodiments may include a forward end of the boom having a similar length across six forward ends of the boom, for example, or any other distribution of the length of the forward end of the boom from the wing (304) to the tilt propeller (314). Some embodiments may include an aircraft (300) having eight electric propulsion systems, including four forward electric propulsion systems (314) and four rear electric propulsion systems (312), or any other distribution of forward and rear electric propulsion systems, including embodiments where the number of forward electric propulsion systems (314) is less or more than the number of rear electric propulsion systems (312). Additionally, Fig. 3 It illustrates an exemplary embodiment of a VTOL aircraft (300) having a forward propeller (314) in the horizontal direction for horizontal flight and a rear propeller blade (320) in the stow position for the forward flight phase.

[0030] As disclosed herein, the forward electric propulsion system and the rear electric propulsion system may be of the clockwise (CW) type or the counterclockwise (CCW) type. Some embodiments may include various forward electric propulsion systems that are a mix of CW and CCW types. In some embodiments, the rear electric propulsion system may be a mix of CW and CCW type systems.

[0031] Fig. 4 is a schematic diagram illustrating an exemplary propeller rotation of a VTOL aircraft according to a disclosed embodiment. The aircraft (400) shown in the drawing is Fig. 1 , Fig. 2 and Fig. 3Each of the aircraft (100, 200, and 300) may be a top plan view. The aircraft (400) may include six forward electric propulsion systems, three of which are of the CW type (424) and the remaining three are of the CCW type. In some embodiments, three of the rear electric propulsion systems may be of the CCW type (428) and the remaining three are of the CW type (430). Some embodiments may include an aircraft (400) having four forward electric propulsion systems and four rear electric propulsion systems, each comprising two CW types and two CCW types. In some embodiments, the propellers may rotate in opposite directions relative to adjacent propellers to cancel out torque steering caused by the rotation of the propellers experienced by the aircraft's fuselage or wings. In some embodiments, the difference in rotation direction may be achieved using the engine rotation direction. In another embodiment, the engines can all rotate in the same direction, and gearing can be used to achieve different propeller rotation directions.

[0032] Some embodiments may include an aircraft (400) having a forward and rear electric propulsion system in which the amounts of the CW type (424) and CCW type (426) are not equal between the forward electric propulsion system, the rear electric propulsion system, or the forward and rear electric propulsion systems.

[0033] Fig. 5... is a schematic diagram illustrating exemplary power connections of a VTOL aircraft according to the disclosed embodiments. A VTOL aircraft may have various power systems connected to diagonally opposite electric propulsion systems. In some embodiments, the power system may include a high-voltage power system. In some embodiments, the high-voltage power system may include an electric engine connected via a high-voltage channel. In some embodiments, the aircraft (500) may include six power systems including batteries (526, 528, 530, 532, 534, and 536) stored within the wings (570) of the aircraft (500). In some embodiments, the aircraft (500) may include six forward electric propulsion systems having six electric engines (502, 504, 506, 508, 510, and 512) and six rear electric propulsion systems having six electric engines (514, 516, 518, 520, 522, 524). In some embodiments, the battery may be connected to an electric engine facing diagonally. In this configuration, the first power system (526) may provide power to the electric engine (502) via a power connection channel (538) and to the electric engine (524) via a power connection channel (540). In some embodiments, the first power system (526) may be paired with the fourth power system (532) via a power connection channel (542) equipped with a fuse to prevent excessive current from flowing through the power systems (526 and 532). In addition to this embodiment, the VTOL aircraft (500) may include a second power system (528) paired with the fifth power system (534) via a power connection channel (548) equipped with a fuse and may provide power to the electric engines (510 and 516) respectively via power connection channels (544, 546).In some embodiments, the third power system (530) may be paired with the sixth power system (536) via a power connection channel (554) equipped with a fuse and may provide power to the electric engines (506, 520) via power connection channels (550 and 552), respectively. The fourth power system (532) may also provide power to the electric engines (508 and 518) via power connection channels (556 and 558), respectively. The fifth power system (534) may also provide power to the electric engines (504 and 522) via power connection channels (560 and 562), respectively. The sixth power system (536) may also provide power to the electric engines (512 and 514) via power connection channels (564 and 566), respectively.

[0034] As disclosed herein, an electric propulsion system may include an electric engine connected to a high-voltage power system, such as a battery located within the aircraft, via a high-voltage channel or a power connection channel. In some embodiments, various batteries may be stored within the aircraft wings, and high-voltage channels may be connected to the electric propulsion system along the entire aircraft, including the wings and booms. In some embodiments, multiple high-voltage power systems may be used to create an electric propulsion system with multiple high-voltage power supplies to avoid the risk of a single point of failure. In some embodiments, the aircraft may include multiple electric propulsion systems that can be wired in a pattern to various batteries or power sources stored throughout the aircraft. It is recognized that this configuration may be advantageous in preventing a single point of failure. That is, if a failure occurs in one battery or power supply, there is a risk that part of the aircraft will not be able to maintain the required thrust, thereby preventing it from continuing flight or performing a controlled landing. For example, if a VTOL is equipped with two forward electric propulsion systems and two rear propulsion systems, the forward and rear electric propulsion systems on opposite sides of the VTOL aircraft may be connected to the same high-voltage power system. In this configuration, even if one high-voltage power system fails, the forward and rear electric propulsion systems on opposite sides of the VTOL aircraft remain operational and can provide a more balanced flight or landing than if the forward and rear electric propulsion systems on the same side of the VTOL aircraft fail. 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.Some embodiments may include various configurations in which the electric engine is electrically connected to a high-voltage power system, thereby preventing the risk of a single point of failure in the event of a power supply failure, allowing the flight phase in which the failure occurred to continue, or allowing the aircraft to perform an alternative flight phase in response to the failure.

[0035] As discussed above, the 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 electric engine(s) that communicate digitally with a flight control system ("FCS") that includes a flight control computer ("FCC") capable of exchanging signals with the electric engine, including command and response data or status. Some embodiments may include an electric engine capable of receiving and transmitting operational parameters from the FCC, including speed, voltage, current, torque, temperature, vibration, propeller position, and other operational parameter values.

[0036] In some embodiments, the flight control system may include a system capable of communicating with the electric engine to transmit and receive analog / discrete signals to the electric engine and controlling a device capable of changing the thrust of the tilt propeller between a direction primarily vertical during vertical flight mode and a direction mostly horizontal during forward flight mode. In some embodiments, this system may be referred to as a tilt propeller system (“TPS”) and may convey additional features of the electric propulsion system and direct it.

[0037] Fig. 6The block diagram illustrates an exemplary structure and design of an electric propulsion unit (600) according to the disclosed embodiment. In some embodiments, the electric propulsion system (602) may include an electric engine subsystem (604) capable of supplying torque to a propeller subsystem (606) via a shaft to generate thrust for the electric propulsion system (602). Some embodiments may include an electric engine subsystem (604) receiving low-voltage DC (LV DC) power from a low-voltage system (LVS) (608). Some embodiments may include an electric engine subsystem (604) receiving high-voltage (HV) power from a high-voltage power system (HVPS) (610) comprising at least one battery or other device capable of storing energy. In some embodiments, the high-voltage power system may include more than one battery or other device capable of storing energy to supply high-voltage power to the electric engine subsystem (604). It is recognized that this configuration can be advantageous in that there is no risk of a single point of failure where the electric propulsion system (602) fails due to a single battery failure.

[0038] Some embodiments may include an electric propulsion system (602) comprising an electric engine subsystem (604) that receives signals from the flight control system (612) and sends signals to the flight control system. In some embodiments, the flight control system (612) may include a flight control computer capable of using controller area network ("CAN") data bus signals to send commands to the electric engine subsystem (604) and to receive status and data from the electric engine subsystem (604). It should be understood that while CAN data bus signals are used between the flight control computer and the electric engine(s), some embodiments may include any form of communication capable of sending and receiving data from the flight control computer to the electric engine. In some embodiments, the flight control system (612) may also include a tilt propeller system ("TPS") (614) capable of transmitting and receiving analog discrete data to and from the electric engine subsystem (604) of the tilt propeller. The tilt propeller system (614) may include a device capable of transmitting operating parameters to the electric engine subsystem (604) and linking the direction of the propeller subsystem (606) to redirect the thrust of the tilt propeller during various flight phases using mechanical means such as a gearbox assembly, a linear actuator, and any other configuration of components to change the direction of the propeller subsystem (606).

[0039] As discussed overall, the example VTOL aircraft may have various types of electric propulsion systems, including tilt propellers and lift propellers, including a forward electric engine capable of tilting during various flight phases and a rear electric engine that maintains one direction and can be activated only during specific flight phases (i.e., takeoff, landing, and hovering).

[0040] Fig. 7[Image] is a schematic diagram illustrating an exemplary tilt electric propulsion system for a VTOL aircraft according to the disclosed embodiment. The tiltable electric propulsion system (700) may include an electric engine assembly (702) aligned along a shaft (724) connected to an output shaft (738) mechanically coupled to a propeller assembly (720) comprising a hub, a spinner, and tilt propeller blades. In some embodiments, the electric engine assembly (702) may include a motor and gearbox assembly (704) aligned along the shaft (724) and mechanically coupled thereto. In some embodiments, the motor and gearbox assembly (704) may include an electric motor assembly comprising a stator (706) and a rotor (708). Fig. 7 As illustrated in and present in some embodiments, the stator (706) may include multiple stator windings connected to the inverter (716). In this configuration, the stator (706) may incorporate one or more multiplexes so that if one set of windings fails, power is still transmitted to the stator (706) through one or more remaining windings, allowing the electric engine assembly (702) to maintain power and continue to generate thrust in the propeller assembly (720).

[0041] In some embodiments, the motor and gearbox assembly (704) may contain a gearbox (710) aligned along the shaft (724) to provide gear reduction between the torque of the shaft (724) from the electric engine assembly, which includes the stator (706) and 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 these embodiments, the oil pump may drive the circulation of oil throughout the motor and gearbox assembly (704) at the same speed as 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 the circulation of oil at a speed greater 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 capable of detecting a magnetic field produced by an electric engine assembly to determine the propeller position. Additional embodiments may include a propeller position sensor (712) driven by an inverter (716) and transmitting data collected by the inverter (716).

[0042] In some embodiments, the electric engine assembly (702) may also include an inverter assembly (714) substantially aligned along the shaft (724). The inverter assembly (714) may include an inverter (716) and an inverter power unit (740). The inverter power unit (740) may receive low-voltage DC power from a low-voltage system (734) located outside the electric engine assembly (702). The inverter power unit (740) may receive low-voltage DC power generated from a high-voltage power system (732) located outside the electric engine assembly (702), which is converted into low-voltage DC power through a DC-DC converter (742). The inverter (716) may supply high-voltage alternating current (AC) to the stator (706) of the electric engine assembly located within the motor and gearbox assembly (704) through at least one three-phase winding. The inverter assembly (714) may include an inverter (716) capable of receiving flight control data from a flight control computing subsystem (736).

[0043] 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 separator plate (744) coupled to the motor and gearbox assembly (704) and the inverter assembly (714). The separator plate (744) may create a sealed environment for the upper part of the motor and gearbox assembly (704) through an end bell assembly and a sealed environment for the lower part of the inverter assembly (714) through a heat plate. In some embodiments, the separator plate (744) may function as an essential mounting bracket to support a heat exchanger (718). The heat exchanger (718) may include, for example, a folded fin or other type of heat exchanger. In some embodiments, the electric propulsion system (700) may circulate oil or other coolant throughout the electric engine assembly (702), the motor and gearbox assembly (704), or the inverter assembly (714) to transfer heat generated from the components to oil or other coolant liquid. Heated oil or other cooling liquid can be circulated through a heat exchanger (718) to transfer heat to an airflow (722) passing through the fins of the heat exchanger.

[0044] In some embodiments, the electric engine assembly (702) may be mounted or coupled to the boom structure (726) of the aircraft. The variable pitch mechanism (730) may be mechanically coupled to the propeller assembly (720). In some embodiments, the variable pitch mechanism may be adjacent to the electric engine assembly (702). In some embodiments, the variable pitch mechanism (730) may be coupled to the variable pitch mechanism (730) so that it may be remotely mounted within the boom, wing, or fuselage of the aircraft. In some embodiments, the variable pitch mechanism (730) may include a component that moves within or adjacent to the shaft (724) of the shaft or propeller assembly (720). The variable pitch mechanism (730) may function to change the collective angle of the propeller assembly blades of the forward electric engine required for operation during the hovering phase, the transition phase, and the cruising phase. Some embodiments may include an electric engine assembly (702) mechanically coupled to a tilt propeller subsystem (728) capable of changing thrust primarily in the vertical direction during vertical flight mode to primarily in the horizontal direction during forward flight mode. In some embodiments, the tilt propeller subsystem may be adjacent to a variable pitch mechanism (730). Some embodiments may include a tilt propeller subsystem (728) comprising various components located at various positions. For example, components of the tilt 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 tilt propeller subsystem (728) may work together to change the thrust of the tiltable electric propulsion system (700).

[0045] Figs. 8a-8c is a diagram of an exemplary tilt electric propulsion system for a VTOL aircraft according to a disclosed embodiment. . Figs. 8a-8crefers to similar elements of electric propulsion systems (800A, 800B, and 800C) that can be tilted with similar numbers. Therefore, similar design considerations and configurations may be considered throughout the embodiments.

[0046] FIGS. 8a and FIGS. 8b Each illustrates a side profile and a perspective view of a tiltable electric propulsion system (800A, 800B) in a cruising configuration integrated into a boom (812A, 812B) according to the present disclosure. The tiltable propeller electric propulsion system (800A, 800B) may include an electric engine assembly (802A, 802B) housed within the boom (812A, 812B) of a VTOL aircraft. In some embodiments, the cruising configuration may include an electric engine assembly (802A, 802B) located within the boom (812A, 812B). The electric engine assembly (802A, 802B) may include an electric motor assembly, a gearbox assembly, an inverter assembly having power connection channels (810A, 810B), and a heat exchanger (804A, 804B) as described herein. The electric engine assembly (802A, 802B) can be mechanically coupled to a shaft flange assembly (806A, 806B), a spinner, and a propeller blade, and a propulsion assembly (808A, 808B).

[0047] Fig. 8c This shows a downward view of an electric propulsion system (800C) that can be tilted in a lift configuration integrated into a boom (812B) according to the present disclosure, along a spinner (808C). Fig. 8c As illustrated in the figure, the tiltable electric propulsion system (800C) in the lift configuration may include an electric engine assembly (802A, 802B) located outside the boom (812C) and changing the direction relative to the boom (812C).

[0048] As discussed herein, a lift electric propulsion system may 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 cruising.

[0049] Fig. 9 [This is a schematic diagram illustrating an exemplary lift electric propulsion system for a VTOL aircraft according to the disclosed embodiment. The lift electric propulsion system (900) may be mounted or coupled to the boom structure (924) of the aircraft. The lift electric propulsion system (900) may include an electric engine assembly (902) aligned along a shaft (940) connected to an output shaft (932) mechanically coupled to a propeller assembly (920) comprising a hub and tilt propeller blades. In some embodiments, the electric engine assembly (902) may include a motor and gearbox assembly housing (904) aligned along the shaft (940) and mechanically coupled thereto. In some embodiments, the motor and gearbox assembly housing (904) may include an electric motor assembly comprising a stator (906) and a rotor (908). The stator (906) may include multiple stator windings connected to an inverter (916). In this configuration, the stator (906) may incorporate one or more multiplexing and supplementing methods to avoid a single point of failure in the event of a power supply failure. For example, the stator (906) may include multiple windings so that, in the event of a winding failure, power continues to be transmitted to the stator (906) through the remaining windings, allowing the electric engine assembly (902) to maintain power and the propeller assembly (920) to continue generating thrust.

[0050] In some embodiments, the motor and gearbox assembly housing (904) may contain a gearbox (910) aligned along the shaft (940) to provide gear reduction between the torque of the shaft (932) from the electric engine assembly, which includes the stator (906) and rotor (908), and the output shaft (932). The torque applied to the output shaft (932) may be transmitted to the propeller assembly (920). Some embodiments may include a gearbox (910) that includes a fluid pump to circulate cooling and / or lubricating fluid. In the illustrated embodiment, the fluid pump is an oil pump. In this embodiment, the oil pump may drive the circulation of oil throughout the motor and gearbox assembly housing (904) at the same speed as the rotation of the 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) present within the housing capable of detecting a magnetic field produced by an electric engine assembly to determine the propeller position. Additional embodiments may include a propeller position sensor (912) driven by an inverter (916) and capable of transmitting collected data to the inverter (916) which can be transmitted to the flight control computing system (930) among other flight control data.

[0051] In some embodiments, the electric engine assembly (902) may also include an inverter assembly housing (914) aligned along an axis that shares the axis of the shaft (924). The inverter assembly housing (914) may include an inverter (916) and an inverter power unit (934). The inverter power unit (934) may receive low-voltage DC power from a low-voltage system (928) located outside the electric engine assembly (902). The inverter power unit (934) may receive low-voltage DC power generated from a high-voltage power system (926) located outside the electric engine assembly (902), which is converted into low-voltage DC power through a DC-DC converter (936). The inverter (916) may supply high-voltage alternating current to the stator (906) of the electric engine assembly located in the motor and gearbox assembly housing (904) through at least one three-phase winding. The inverter assembly (914) may include an inverter (916) capable of transmitting and receiving data with the flight control computing subsystem (930).

[0052] 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 separator plate (938) coupled to the motor and gearbox assembly housing (904) and the inverter assembly housing (914). The separator plate (938) may create a sealed environment for the upper part of the motor and gearbox assembly housing (904) through an end bell assembly and a sealed environment for the lower part of the inverter assembly housing (914) through a heat plate. In some embodiments, the separator plate (938) may function as an essential mounting bracket for supporting a heat exchanger (918). The heat exchanger (918) may include, for example, a folded fin or other type of heat exchanger. In some embodiments, the electric propulsion system (900) may circulate oil or other coolant fluid throughout the electric engine assembly (902), motor and gearbox assembly (904), or inverter assembly (914) to transfer heat generated from the components to the oil or other coolant fluid. The heated oil or other coolant fluid may be circulated through a heat exchanger (918) to transfer heat to an airflow (922) passing through the fins of the heat exchanger.

[0053] In some embodiments, tiltable electric propulsion systems and lift electric propulsion systems may have similar components. This can be advantageous in relation to many design considerations present within VTOL aircraft. For example, in terms of manufacturability, different types of electric propulsion systems with similar components may be advantageous in terms of manufacturing efficiency. Additionally, having similar components can be advantageous in terms of risk management, as similar components have similar failure points, and these failure points can be better identified and designed when comparing systems with similar components to systems with different components and configurations.

[0054] Additionally, while the tiltable electric propulsion system may have different components compared to the lift electric propulsion system in some embodiments, it should be understood that in some embodiments the tiltable electric propulsion system and the lift electric propulsion system may have the same configuration of components. For example, in some embodiments the tiltable and lift electric propulsion systems may contain the same components, whereas the lift electric propulsion system may be coupled to the boom, wing, or fuselage of the aircraft and may not provide thrust in as many directions as the tiltable electric propulsion system.

[0055] Figs. 10a-10b is a diagram of an exemplary lift electric propulsion system for a VTOL aircraft according to a disclosed embodiment. . Figs. 10a and 10b refers to similar elements of the lift electric propulsion system (1000A and 1000B) having similar numbers. Therefore, similar design considerations and configurations can be considered throughout the embodiments.

[0056] Fig. 10a This shows a side profile of a lift electric propulsion system (1000A) in a lift configuration integrated into a boom (1010A) according to the present disclosure. 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 an electric engine assembly (1002A) positioned vertically within the boom (1010A). 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) as described herein. The electric engine assembly (1002A) may be mechanically coupled to a propulsion assembly (1006A) comprising a shaft flange assembly and propeller blades.

[0057] Fig. 10bThis shows a downward view of a lift electric propulsion system (1000B) in a lift configuration integrated into a boom (1010B) according to the present disclosure.

[0058] Some embodiments of the disclosed electric engine may include a thermal management system to prevent heat from being generated during operation and to ensure that components of the electric engine do not fail during operation. In some embodiments, coolant may be used and circulated through parts of individual components of the engine, such as an inverter, gearbox, or motor, or through all components of the engine to help manage the heat present in the engine. Some embodiments may include a step of using an air cooling method to cool the electric engine or a step of using a mixture of coolant and air to manage the heat generated during operation in the electric engine. 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 engine may be cooled using liquid or air, or using air-liquid mixed cooling. As another example, the motor may be cooled using air cooling, while the inverter and gearbox are cooled using liquid cooling. It should be understood that mixed cooling may be used in any combination of electric engine components or within each component.

[0059] In some embodiments, oil may be used as a lubricant throughout the electric engine and may also be used as a coolant fluid to assist in managing the heat generated by the engine during operation. In addition to this example, different amounts of oil, such as 1 quart, 1.5 quarts, 2 quarts, 2.5 quarts, 3 quarts, 5 quarts or less, or any other amount of oil required to lubricate and cool the electric engine, with or without the assistance of air cooling, may be used to function as both a lubricant and a coolant fluid in the electric engine. In some embodiments, the amount of oil or liquid to be used in the system in relation to cooling may be determined based on the amount of thermal capacity required to drive heat transfer from the components of the electric propulsion system. As disclosed herein, the electric engine may have different primary functions, such as being used only for lifting and landing, used in only one direction, or used during all phases of flight, such as lifting, landing, and flight. Engines used in all phases of flight may experience various orientations throughout the flight and may contain more lubricating oil and coolant than engines used in only one orientation. Therefore, not all engines of an aircraft may contain the same amount of lubricating oil and coolant. For example, lifting and landing engines may require less than 1 quart of oil, while engines operating in all phases of flight may require more than 1 quart of oil. In some embodiments, the amount of oil or liquid for cooling may be an appropriate amount to provide sufficient thermal capacity to drive heat transfer from the components of the electric propulsion system regardless of the orientation of the electric propulsion system. The embodiments discussed herein are illustrative and non-limiting and do not indicate a range of amounts of lubricating oil and coolant that may be used in electric engines.

[0060] In some embodiments, oil may be used to lubricate and cool the electric engine. These embodiments may require an additional amount of oil. In these embodiments, the additional oil may eliminate traditional components that could be used to cool the electric engine. For example, if the electric engine is cooled by another liquid such as glycol, the engine may include separate heat exchangers for both the lubricating fluid and the cooling fluid. Thus, in embodiments where a single fluid, such as oil, is used for both lubrication and cooling, although an increase in oil is present, only one heat exchanger may be required; therefore, the mass of the overall system is reduced and a more attractive drag profile may exist because fewer heat exchangers are used and potentially other components are not needed. Furthermore, using a single material for lubricating and cooling the engine can increase efficiency due to the reduction in mass and the benefit of cooling the engine with the material instead of relying on air cooling, which may be problematic to move throughout the engine.

[0061] Some embodiments of the electric engine may include various components to monitor combustible fluids and prevent combustible materials from entering specific sections of the electric engine. Some embodiments may include an electric engine having a wet zone enclosure that may be defined by a gearbox, a motor, and / or a heat exchanger. In some embodiments, the electric engine may have up to 4 liters or more of air within the motor-gearbox housing in contact with the engine oil. Embodiments of the motor-gearbox housing may use a breather to equalize internal and external pressures. Embodiments of the breather may include protrusions over surrounding design features to prevent inadvertent entry of external fluids. Some embodiments may include a breather having a bypass entry path and a screen to prevent entry of external debris. Embodiments may include a viewing window present in both the tilt and lift electric engines to check whether the oil is overfilled or underfilled during service.

[0062] Some embodiments of the electric engine may include active protection functions for the front and rear electric engines, such as monitoring vibration throughout the engine and internal temperatures like oil temperature, stator winding set temperature, inverter-enclosing capacitor temperature, power module temperature, control panel power module temperature, control panel control processor temperature, control panel monitor processor temperature, and internal hotspot temperature, as well as various other operating conditions throughout the engine as needed. Such monitoring can be achieved using various sensors located throughout the electric propulsion system and the aircraft. Embodiments may include vibration limits based on known failure points or component resonance, and temperature overload limits based on operating limits regarding known failure temperatures and fluid auto-ignition points. In some embodiments, the 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 transmitted to or displayed by the flight control system. In some embodiments, in response to the detection of operating conditions, the flight control system may operate to reduce the amount of power directed to the electric propulsion system. Some embodiments may include a step of reducing the amount of power to the electric propulsion system to reduce friction sparks or mechanical wear from vibration and / or a step of reducing power to reduce the temperature of components present within the electric propulsion system. Additionally, some embodiments may include a step of reducing power to the electric propulsion system when the perceived efficiency of the inverter is lower than the target efficiency. In some embodiments, for example, when 12 electric propulsion systems are present in the aircraft, the flight control system may increase the power directed toward the remaining electric propulsion systems or some thereof to compensate for the reduction in lift produced by one electric propulsion system while reducing or terminating power to a single electric propulsion system.In some embodiments, the flight control system may set operating conditions of various thresholds to respond to a decrease or increase in power to the electric propulsion system.

[0063] Some embodiments may include a high-voltage power system that may have a fuse at a high-voltage battery terminal capable of rapidly and irreversibly disconnecting the engine electrical connection to mitigate and avoid the case of overcurrent. This overcurrent protection may be activated when the electric engine current demand is greater than the overcurrent operating value. Thus, in some embodiments, fault conditions causing overcurrent may only cause transient overheating, arc, or spark faults. Some embodiments may include a fire threat characterization test ignition source that may be selected as a more severe ignition source than a short circuit occurring in the electric engine and opened by the engine fuse. In some embodiments, the inverter may detect AC overcurrent and isolate the wrong phase and / or continuously monitor the input DC voltage and apply protection measures to maintain the voltage below the overvoltage operating limit.

[0064] During takeoff, landing, hovering, and cruising, the motors and associated control components of a VTOL aircraft can generate heat. This heat must be dissipated to prevent degradation and damage to the motors, control components, and other elements of the VTOL aircraft. For some types of VTOL aircraft, such as electric VTOL (eVTOL) aircraft, thermal control is equally important, for example, to maintain the optimal energy efficiency of battery-powered components.

[0065] Some elements may generate high heat loads only during specific operating periods. For example, some lift propellers may be used only during takeoff, landing, and hovering, and remain stationary during cruising. Therefore, these lift propellers may generate high heat loads during takeoff, landing, and hovering, and generate little to no heat during cruising.

[0066] B. Example of an electric propulsion system

[0067] As described herein, embodiments of an electric engine may include an inverter assembly, a gearbox assembly, and an electric motor assembly, or various combinations thereof. In some embodiments, the inverter assembly, the gearbox assembly, and the electric motor assembly may be substantially aligned along the central axis of the electric engine. As disclosed herein, these assemblies or combinations thereof may be substantially aligned along an axis by sharing a common axis or by having parallel axes within a distance of 5% or less of the outer diameter of the component having the largest diameter of each other. For example, the inverter assembly, the gearbox assembly, and the electric motor assembly may be substantially aligned along a central axis in which the central axis of the inverter assembly, the central axis of the gearbox assembly, and the central axis of the electric motor assembly are within a distance of 5% or less of the outer diameter of the electric motor assembly, in which the electric motor assembly has an outer diameter larger than that of the gearbox assembly and the inverter assembly. It should be understood that the embodiments described herein are merely examples, and while specific components of the electric propulsion system may appear adjacent to other components, all adjacent configurations may exist. For example, the gearbox assembly may appear adjacent to the inverter assembly and the electric motor assembly. Additionally, in some embodiments, the inverter assembly may be adjacent to the gearbox assembly and the electric motor assembly. Some embodiments may include an electric motor assembly adjacent to the gearbox assembly and the inverter assembly.

[0068] In some embodiments, the inverter assembly, the gearbox assembly, and the electric motor assembly may each be adjacent to at least one of the other assemblies. Adjacentness may include direct or indirect contact between components, including the assembly or the housing in which the assembly is located. In some embodiments, the electric engine may include the inverter assembly and the electric motor assembly without the gearbox assembly. Some embodiments of the electric engine may include the electric motor assembly and the gearbox assembly without the inverter assembly, or the electric motor assembly without the gearbox assembly or the inverter assembly.

[0069] Figs. 11a-11c is a cross-sectional view of an exemplary electric propulsion system of a VTOL aircraft according to a disclosed embodiment. Fig. 11a This illustrates an example of an electric propulsion system. In some embodiments, the electric engine may directly assist in the propulsion of the propeller for the aircraft. The electric engine (1100A) may include a motor housing (1102A). The electric engine (1100A) may also include an electric motor assembly comprising components such as a stator (1104A), a rotor magnet (1106A), and a rotor (1108A). In some embodiments, the rotor (1108A) may be mechanically coupled to the main shaft (1110A) so that the main shaft (1110A) rotates at the same speed as the rotational speed of the rotor (1108A). The main shaft (1110A) may be mechanically coupled to a shaft flange assembly (1112A). In some embodiments, the shaft flange assembly (1112A) may be a fixed point of the propeller. The electric motor assembly may be substantially aligned along a central axis (1114A).

[0070] In some embodiments, the electric engine may include a gearbox. Fig. 11bThis illustrates an example of an electric engine. In some embodiments, the electric engine may include a gearbox assembly and an electric motor assembly substantially aligned along a shaft. In some embodiments, the electric motor assembly, the gearbox assembly, and the shaft may be substantially aligned along an axis (1114B). The electric engine (1100B) may include a motor housing (1102B), a stator (1104B), a rotor magnet (1106B), and a rotor (1108B). In some embodiments, the rotor (1108B) may be mechanically coupled to the main shaft (1110B) so that the main shaft (1110B) rotates at the same speed as the rotational speed of the rotor (1108B). The main shaft (1110B) may be mechanically coupled to the shaft flange assembly (1112B), and further to the shaft flange assembly (1112B) so that a propeller assembly (not illustrated) can rotate at the same speed as the rotational speed of the main shaft (1110B). In some embodiments, the gearbox assembly may provide gear reduction and change the rotational speed of the main shaft (1110B). For example, the electric engine (1102B) may include a gearbox assembly comprising a sun gear (1116B), a planetary gear (1118B), a ring gear (1020B), and a planetary carrier (1122B). In some embodiments, the sun gear (1116B) may be mechanically coupled to the main shaft (1110B) so that the sun gear (1116B) rotates at the same speed as the main shaft (1110B). The sun gear (1116B) may be interfaced with the planetary gear (1118B), which also interfaces with the ring gear (1120B). In this embodiment where the sun gear (1116B) rotates, the ring gear (1120B) may be fixed to the motor housing (1102B). In some embodiments, the planetary gear (1118B) may rotate around the sun gear (1116B) due to interaction with the rotating sun gear (1116B) and the fixed ring gear (1120B).The planetary carrier (1122B) may be mechanically coupled to the planetary gear (1118B) and may rotate at the same speed. Some embodiments may include a planetary carrier (1122B) mechanically coupled to a main shaft (1110B). In some embodiments, the main shaft (1110B) may include multiple phases or layers of the shaft so that a portion of the shaft may rotate at a different speed. Some embodiments may include a first portion of the main shaft rotating at the same speed as the rotor (1108B) and another portion of the main shaft rotating at the same speed as the planetary carrier (1122B). In some embodiments, the speed of the planetary carrier may be lower than the speed of the rotor (1108B).

[0071] In some embodiments, the electric engine (1100B) may include bearings (1124B, 1126B) aligned along the main shaft (1110B). Some embodiments may include bearings (1124B, 1126B) mechanically coupled to a planetary carrier and inner rings of various bearings such as 1124B and 1126B.

[0072] Fig. 11cThis illustrates an example of an electric propulsion system. In some embodiments, the electric propulsion system may include a gearbox assembly and an electric motor assembly substantially aligned along a shaft. In some embodiments, the electric motor assembly may be located between the gearbox assembly and the shaft flange assembly. The electric propulsion system (1100C) may include a motor-gearbox assembly housing (1102C). In some embodiments, the electric propulsion system (1100C) may include an electric motor assembly comprising a stator (1104C), a rotor magnet (1106C), and a rotor (1108C). The electric propulsion system (1100C) may also include a gearbox assembly. In some embodiments, the gearbox assembly may include a sun gear (1116C), a planetary gear (1118C), a ring gear (1120C), and a planetary carrier (1122C). The sun gear (1116C) can be interfaced with a planetary gear (1118C) which can also be interfaced with a ring gear (1120C). The sun gear (1116C) can be mechanically coupled to the rotor (1106C) so that the rotation of the rotor (1106C) can rotate the sun gear (1116C) at the same rotational speed. The planetary carrier (1122B) can be mechanically coupled to the planetary gear (1118C) and can rotate at the same speed. Some embodiments may include a planetary carrier (1122C) mechanically coupled to a main shaft (1110C). The main shaft (1110C) can be mechanically coupled to a shaft flange assembly (1112C). The main shaft (1110C) can be substantially aligned along the central axis (1114C) so that the gearbox assembly and the motor assembly are also substantially aligned along the central axis (1114C). In some embodiments, the electric propulsion system (1100C) may include a heat exchanger (1124C) that can be used to cool a liquid or oil used to cool or lubricate components of a gearbox assembly or an electric motor assembly.

[0073] The electric propulsion systems (1100A-C) are exemplary embodiments as discussed above. However, it should be understood that while the electric propulsion system (1100A) can provide the thrust required for a VTOL aircraft, it can generate a larger drag profile than the electric propulsion systems (1100B and 1100C) and contribute more mass to the VTOL aircraft. The electric propulsion systems (1100B and 1100C) include a gearbox assembly. Thus, the electric propulsion systems (1100B and 1100C) have an electric motor assembly, and thus a gear reduction that causes the electric propulsion system to have a smaller drag profile and less mass.

[0074] The electric propulsion system (1100B) may have a gearbox assembly between the electric motor assembly and the shaft flange assembly. This configuration may require less mass than the electric propulsion system (1100A), while requiring more mass than the electric propulsion system (1100C). The electric propulsion system (1100B) may have a gearbox assembly such that an input shaft or sun gear moves from the electric motor assembly to the gearbox assembly, and an output shaft or part of a planetary carrier moves from the gearbox assembly to the shaft flange assembly. On the other hand, in some embodiments, the electric propulsion system (1100C) may include a sun gear that moves from the rotor of the electric motor assembly to the gearbox assembly, and a main shaft coupled to a planetary carrier or carrier cover that moves through the electric motor assembly to the shaft flange assembly via the sun gear. Thus, the electric propulsion system (1100C) may have a more compact design, housing, and drag profile compared to the electric propulsion system (1100B). This can produce a more efficient drag profile and a more mass-efficient system. Additionally, the electric propulsion system (1100B) may have a gearbox assembly without a lubrication means that could limit the runtime of the electric propulsion system. The electric propulsion system (1100C) may include a heat exchanger to cool and lubricate parts of the system, including the gearbox assembly. This can result in additional efficiency and a long flight range time.

[0075] Fig. 49[This section] illustrates a cross-sectional view of an exemplary electric propulsion system for a VTOL aircraft according to the disclosed embodiment. The electric propulsion system (4900) may include a system that initially transmits torque away from the propeller and may bring torque back to the propeller through part of the system. In some embodiments, the electric propulsion system (4900) may include a motor-gearbox assembly housing (4922), an inverter assembly housing (4924), and a heat exchanger (4926). In some embodiments, the electric motor assembly may include a stator (4902) and a rotor (4904). In some embodiments, the electric propulsion system (4900) may include a gearbox assembly comprising a sun gear (4906), a planetary gear (4908), a ring gear (4910), and a planetary carrier (4912). The sun gear (4906) may be mechanically coupled to the rotor (4904). The sun gear (4906) may be connected to the planetary gear (4908) via an interface. The planetary gear (4908) can be interfaced with the ring gear (4910) which can be fixed so that the planetary gear (4908) rotates against the sun gear (4906) against the ring gear (4910). In some embodiments, the planetary gear (4908) may include a compound planetary gear (4908, 4950). A planetary carrier (4912) may extend from the planetary gear (4908) along the central axis (4916) of the planetary gear and may be mechanically coupled to the planetary gear (4908) via a shaft (4914) which can be received by the planetary carrier (4912). The planetary carrier (4912) may rotate at the same speed as the planetary gear (4908). The planetary carrier (4912) may be mechanically coupled to the main shaft (4918) so that the main shaft (4918) can rotate at the same speed as the planetary carrier (4912). In some embodiments, the planetary gear (4908) may be mechanically coupled to the carrier cover so that the carrier cover can rotate at the same speed as the planetary gear (4908).The main shaft (4918) may be mechanically coupled to the shaft flange assembly (4920) so that the shaft flange assembly (4920) can rotate at the same speed as the main shaft (4918). It should be understood that the planetary gear (4908) or compound planetary gear (4908, 4950) may include multiple planetary gears rotating relative to the sun gear (4906).

[0076] As described in this specification, due to mechanical coupling, torque can be transmitted from the rotor (4904) to the sun gear (4906) along path (4930). The sun gear (4906) can transmit torque to the planetary gear (4908) along paths (4932 and 4934). The planetary gear (4908) and, in some embodiments, the compound planetary gear (4908, 4950) can transmit torque to the planetary carrier along paths (4936 and 4938). The planetary carrier can transmit torque to the main shaft (4918) along path (4940). The main shaft (4918) can transmit torque to the propeller assembly (4920) along its length via path (4944). The propeller assembly (4920) can transmit torque to the propeller via paths (4946 and 4948). It should be understood that the path discussed above is an example, and that all configurations consisting of the steps of transmitting torque away from the propeller to the gearbox assembly and then transmitting the torque back to the propeller through the gearbox assembly and the electric motor assembly are considered.

[0077] In some embodiments, the process of transmitting power from an electric engine using a gearbox assembly through a reverse torque path may include the step of driving a planetary gear mechanically coupled to the rotor of an electric motor assembly. In some embodiments, the planetary gear may be connected to an interface with a sun gear and a ring gear. Some embodiments may include a hollow sun gear and a fixed ring gear. Some embodiments may include the step of driving a planetary carrier connected to a shaft extending from the planetary gear. The shaft extending from the planetary gear may include a shaft aligned along the central axis of the planetary gear. Some embodiments may include the step of driving a carrier cover connected to a shaft from a shaft extending concentrically from the planetary gear. Some embodiments may include the step of driving a main shaft. The step of driving the main shaft may include driving a first portion of the main shaft mechanically coupled to the carrier cover and transmitting torque along the main shaft to a second portion of the main shaft mechanically coupled to a propeller assembly. Some embodiments may include a heat exchanger capable of cooling the gearbox assembly using various amounts of oil, which may include 1 quart, 1.5 quarts, 2 quarts, 2.5 quarts, 3 quarts, or 5 quarts, as described in this specification.

[0078] In some embodiments, the gearbox assembly may include multiple sets of gearboxes. For example, in some embodiments, the output terminal of the gearbox assembly may enter another gearbox assembly to achieve a greater gear reduction. Such embodiments may include at least one sun gear, at least one planetary gear set, at least one ring gear, and at least one planetary carrier. The gearbox may have common gears such as a common sun gear, a common planetary gear set, and a common ring gear. The embodiments discussed herein may be modified to include multiple sets of gearboxes.

[0079] Fig. 53 This illustrates a flowchart of an exemplary process for transmitting torque from an electric motor assembly to a propeller assembly of a VTOL aircraft (5300) according to the disclosed embodiment. While the block diagram may be described below in relation to specific embodiments presented in other drawings, such embodiments are provided for exemplary purposes only and are not intended to limit the block diagram.

[0080] Fig. 53 The process blocks (5302 to 5312) are included. In block (5302), the process of transmitting power from an electric engine using a gearbox assembly may include the step of driving a planetary gear mechanically coupled to the rotor of an electric motor, as per the discussion throughout the entire disclosure.

[0081] The process of transmitting power from an electric engine using a gearbox assembly in block (5304) may include the step of driving a planetary carrier connected to at least one shaft extending concentrically from a planetary gear, as per the discussion throughout the present disclosure.

[0082] The process of transmitting power from an electric engine using a gearbox assembly in block (5306) may include the step of driving a carrier cover connected to at least one shaft from a set of shafts extending concentrically from a planetary gear, as per the discussion throughout the entire disclosure.

[0083] The process of transmitting power from an electric engine using a gearbox assembly in block (5308) may include a step of driving a main shaft, which follows the entire discussion of the present disclosure.

[0084] The process of transmitting power from an electric engine using a gearbox assembly in block (5310) may include the step of driving a first portion of a main shaft mechanically coupled to a carrier cover, as per the entire discussion of the present disclosure.

[0085] The process of transmitting power from an electric engine using a gearbox assembly in block (5312) may include the step of transmitting torque along a main shaft to a second part of a main shaft mechanically coupled to a propeller assembly, as per the entire discussion of the present disclosure.

[0086] Figs. 12a-12d is an illustration and block diagram of an exemplary electric propulsion system for a VTOL aircraft according to a disclosed embodiment.

[0087] As described herein, the electric propulsion system may include an inverter assembly, a gearbox assembly, and an engine assembly. In some embodiments, the electric propulsion system (1200A) may include components packaged in various housings, including a motor-gearbox assembly housing (1202A) and an inverter assembly housing (1228A). The step of enclosing the various components of the electric propulsion system (1200A) in the housings (1202A and 1228A) may provide various advantages, including a lower mass and a more efficient drag profile, as described herein. Additionally, in some embodiments, the gearbox assembly, the inverter assembly, and / or the electric motor assembly may have a substantially circular profile. As used herein, the profile may be substantially circular such that the length of the minor axis and the length of the major axis of the circle are related such that the length of the minor axis is at least a critical amount, such as 80% of the length of the major axis. Additionally, in some embodiments, the gearbox assembly, the inverter assembly, and the electric motor assembly, or some of these listed, may be sized so that the assemblies have substantially the same radius. As used herein, assemblies may have substantially the same radius, such that the difference in radius between two assemblies is less than a critical amount, such as 10% of the radius of the assembly with the largest radius. In some embodiments, as described herein, the profiles of the components forming the electric propulsion system may include various polygons, such as hexagons, heptagons, octagons, nonagons, decagons, and additional polygons having more than 10 faces.

[0088] The electric propulsion system (1200A) may include an electric motor assembly comprising a stator (1204A), a rotor magnet (1206A), and a rotor (1208A).

[0089] In some embodiments, the electric motor assembly may interact with the gearbox assembly and, in some embodiments, may transmit torque to the gearbox assembly. The electric propulsion system (1200A) may include a gearbox assembly comprising a sun gear (1214A), a planetary gear set (1216A), a planetary carrier (1218A), and a carrier cover (1220A). Some embodiments may include a sun gear (1214A) having teeth that interact with the teeth of the planetary gear (1216A), and a ring gear (not shown) having teeth that also interact with the teeth of the planetary gear (1216A). In some embodiments, a shaft (1222A) may extend from or through the planetary gear (1216A). In some embodiments, the planetary carrier (1218A) may receive a first end of the shaft (1222A) so that the planetary carrier (1218A) can rotate at the same speed as the planetary gear (1216A). In some embodiments, the carrier cover (1220A) may receive a second end of the shaft (1222A) so that the carrier cover (1220A) can rotate at the same speed as the planetary gear (1216A). In some embodiments, the planetary gear (1216A), the planetary carrier (1218A), and the carrier cover (1220A) may be mechanically coupled along the axis of the shaft (1222A).

[0090] In some embodiments, the electric propulsion system (1200A) may include a main shaft (1210A) that can be mechanically coupled to a shaft flange assembly (1224A) to provide mechanical axial power for rotating the propeller of the propeller assembly. As used herein, components may be mechanically coupled where any connection or coupling exists between the two components, whether direct or indirect. The shaft flange assembly may include a flange coupled to the main shaft by a spline connection to reduce the torque load from the main shaft and to transfer torque to the propeller coupled to the flange. The flange may also be coupled to the main shaft using fasteners by welding, brazing, or any other method or use of the component to join the main shaft and the flange. In some embodiments, the main shaft and the flange may be machined together to form a single component. In some embodiments, the shaft flange assembly may be a component of a propeller assembly that may include a shaft flange assembly, a propeller, and a spinner. In some embodiments, the shaft flange assembly may also be referred to as a propeller hub.

[0091] In some embodiments, the electric propulsion system (1200A) may include components for an inverter assembly as described herein. For example, the electric propulsion system (1200A) may include a printed circuit board assembly (PCBA), such as a power PCBA (1230A) that may include a power module (1232A), a gate drive PCBA (1236A), and a control PCBA (1240A). Some embodiments of the inverter assembly of the electric propulsion system (1200A) may also include a spacer board (1238A) among the various PCBAs. Additionally, some embodiments may include an energy storage device, such as a DC capacitor that may be stored within a DC capacitor housing (1234A). Some embodiments of the inverter assembly may also include a busbar connector (1244A) to supply alternating current to an electric motor assembly. Some embodiments of the inverter assembly may include a power connection (1246A) connected to a high-voltage connector to deliver high-voltage power to the inverter assembly.

[0092] Some embodiments of the inverter assembly of the electric propulsion system (1200A) may include the step of layering individual inverter assembly components in a stacked configuration along guide pins (1242A) extending through each layer of the inverter assembly. It is confirmed that an inverter assembly utilizing a stacked configuration along guide pins (1242A) may be advantageous in various design criteria related to VTOL aircraft. For example, the stacked configuration may enable more compact packaging of the inverter assembly, which helps minimize the mass of the electric propulsion system (1200A) and minimize drag experienced due to the electric propulsion system packaging. Additionally, the stacked configuration of the inverter assembly may be advantageous from a manufacturing perspective, as the stacked configuration allows for tolerances within various parts of the inverter assembly. In some embodiments, structural components may be introduced into the inverter assembly to help support the stacked configuration under loads experienced during various flight phases. Some embodiments may include inverter assembly components that also function as structural components. For example, the DC capacitor housing (1234A) can accommodate not only the capacitor for the inverter assembly but also other components and can be made of plastic or other materials that can support the PCBA and other components around it.

[0093] In some embodiments, the electric propulsion system (1200A) may include a heat exchanger (1226A) coupled to a motor-gearbox assembly housing (1202A) and an inverter assembly housing (1228A). The heat exchanger (1226) may be coupled to a separator plate comprising a heat plate (1248A) and an end bell plate (1250A). The end bell plate (1250A) may function to close the motor-gearbox assembly housing (1202A). The heat plate (1248A) may function to close the inverter assembly housing (1228A). In some embodiments, the separator plate may function as an essential mounting bracket to support the heat exchanger (1226A). The heat exchanger (1226A) may include, for example, a folded fin or other type of heat exchanger. In some embodiments, the electric propulsion system (1200A) may circulate oil or other coolant throughout the electric motor assembly, gearbox assembly, or inverter assembly to transfer heat generated from the components to the oil or other coolant liquid. The heated oil or other coolant liquid may be circulated through the fins of the heat exchanger (1226A) by an internal liquid passage that may have an inlet and an outlet of a liquid passage that may be coupled to the outlet and inlet of a hole or groove that may be present in the separator plate, respectively. In some embodiments, the motor-gearbox housing (1202A) may include an oil tank (1212A). The oil tank (1212) may function to collect the oil or liquid coolant distributed throughout the electric propulsion system (1200A) and to recirculate the oil or liquid coolant.

[0094] In some embodiments, the heat exchanger may be fluidly coupled to a gearbox assembly, an inverter assembly, and / or an electric motor assembly. As used herein, the assembly or its components may be fluidly coupled where a liquid flow path from the heat exchanger interacts with the assembly or its components, supplies liquid thereto, or is connected to the assembly or its components via an interface.

[0095] Fig. 12bThe figure illustrates an example schematic diagram of the configuration of an electric propulsion system (1200B). In some embodiments, the electric propulsion system may include a motor assembly and a gearbox assembly. The electric propulsion system (1200B) includes a separator plate (1208B), a motor assembly (1202B), an inverter assembly (1204B), a gearbox assembly (1206B), a heat exchanger (1212B), and a propeller assembly (1210B). In some embodiments, an inverter assembly housing (1216B) may surround the inverter assembly (1204B), and a motor-gearbox housing (1214B) may surround the motor assembly (1202B) and the gearbox assembly (1206B). The inverter assembly housing (1216B) may be adjacent to the motor-gearbox housing (1214B). In some embodiments, the electric propulsion system (1200B) may include a gearbox assembly (1206B) located between the electric motor assembly (1202B) and the inverter assembly (1204B). As described herein, a lubricating oil or cooling water, such as oil, may be distributed throughout the electric propulsion system. For example, an oil flow (1218B) may have a path from the heat exchanger (1212B) to the separator (1208B), then to the gearbox assembly (1206B) and the motor assembly (1202B), thereby providing cooling and lubrication to the motor assembly (1202B) and the gearbox assembly (1206B). The oil flow (1218B) may then move from the motor assembly (1202B) back to the heat exchanger (1212B). As described in this specification, the propeller assembly (1210B) can drive an airflow (1220B) from the propeller toward the heat exchanger (1212B). The heat exchanger (1212B) can transfer heat from the oil flow (1218B) to the airflow (1220B). The oil flow (1218B) can be cooled and exit the heat exchanger (1212B).

[0096] Fig. 12cThis illustrates an example schematic diagram of the configuration of an electric propulsion system. In some embodiments, the electric propulsion system (1200C) may include a separator (1208C), a motor assembly (1202C), an inverter assembly (1204C), a gearbox assembly (1206C), a heat exchanger (1212C), and a propeller assembly (1210C). In some embodiments, an inverter assembly housing (1216C) may surround the inverter assembly (1204C), and a motor-gearbox housing (1214C) may surround the motor assembly (1202C) and the gearbox assembly (1206C). The inverter assembly housing (1216C) may be adjacent to the motor-gearbox housing (1214C). In some embodiments, the electric propulsion system (1200C) may include an electric motor assembly (1202C) located between the gearbox assembly (1206C) and the inverter assembly (1204C). As described in this specification, a lubricating oil or coolant, such as oil, may be distributed throughout the electric propulsion system. For example, an oil flow (1218C) may have a path from a heat exchanger (1212C) to a separator (1208B), then to a motor assembly (1202C), and then to a gearbox assembly (1206C) to provide cooling and lubrication to the motor assembly (1202C) and the gearbox assembly (1206C). The oil flow (1218C) may then move from the motor assembly (1202C) back to the heat exchanger (1212C). As described in this specification, a propeller assembly (1210C) may drive an air flow (1220C) from the propeller toward the heat exchanger (1212C). The heat exchanger (1212C) may transfer heat from the oil flow (1218C) to the air flow (1220C). The oil flow (1218C) can be cooled and exit the heat exchanger (1212C).

[0097] Fig. 12d[This section] illustrates an example schematic diagram of the configuration of an electric propulsion system. In some embodiments, the electric propulsion system may include a motor and a propeller assembly. The electric propulsion system (1200D) may include a separator (1208D), a motor assembly (1202D), an inverter assembly (1204D), a heat exchanger (1212D), and a propeller assembly (1210D). In some embodiments, an inverter assembly housing (1216D) may surround the inverter assembly (1204D), and a motor assembly housing (1214D) may surround the motor assembly. The inverter assembly housing (121D) may be adjacent to the motor assembly housing (1214D). In some embodiments, the electric propulsion system (1200C) may include an electric motor assembly (1202C) that directly drives a main shaft providing mechanical shaft power to the propeller assembly (1210C). In these embodiments, the main shaft may rotate at the same speed as the rotor within the electric motor assembly (1202). As described in this specification, a lubricating oil or coolant, such as oil, may be distributed throughout the electric propulsion system. For example, an oil flow (1218D) may have a path from a heat exchanger (1212D) to a separator (1208D), and then to a motor assembly (1202D) to provide cooling and lubrication to the motor assembly (1202D) and other components of the electric propulsion system (1200D). The oil flow (1218D) may then move from the motor assembly (1202D) back to the heat exchanger (1212D). As described in this specification, a propeller assembly (1210D) may drive an air flow (1220D) from the propeller toward the heat exchanger (1212D). The heat exchanger (1212D) may transfer heat from the oil flow (1218D) to the air flow (1220D). The oil flow (1218D) can be cooled and exit the heat exchanger (1212D).

[0098] Fig. 13[Image] is an illustration of an exploded view of an exemplary electric propulsion system for a VTOL aircraft according to the disclosed embodiments. The electric engine (1300) may include an inverter assembly (1304), an end bell assembly (1306), a main shaft assembly (1308), a rotor (1310), a stator housing (1312), and a shaft flange assembly (1314). In some embodiments, the inverter assembly (1304) may be adjacent to a gearbox assembly. The gearbox assembly may include an end bell assembly (1306) and a main shaft assembly (1308). In some embodiments, the gearbox assembly may be adjacent to an electric motor assembly. The electric motor assembly may include a rotor (1310) and a stator housing (1312). In some embodiments, the components of the electric propulsion system may be substantially aligned along an axis. In some embodiments, the main shaft may represent a central axis along which the components of the electric propulsion system (1300) are substantially aligned. In an alternative embodiment, the order of the inverter assembly, gearbox assembly, and motor assembly may be rearranged so that different electric propulsion system components are adjacent to each other as described herein. The housing of the inverter assembly (1304) may be attached to the heat plate of the inverter assembly by a screw (1302). In some embodiments, a fastener (1316) may attach the electric engine (1300) to the boom of the aircraft.

[0099] An embodiment of the electric engine may include an electric motor assembly as described in this specification. Fig. 14[Image] is an exploded view of an exemplary electric motor assembly of a VTOL aircraft according to the disclosed embodiment. The electric motor assembly (1400) may include a stator assembly (1402). In some embodiments, the stator may include a lamination and coil of insulated wire. In some embodiments, the stator assembly (1402) may include a permanent magnet. The stator assembly (1402) may include a stator core (1404) and a wire winding (1406). In some embodiments, the wire winding (1406) may be made of copper. The stator assembly (1402) may also include a busbar (1408). For example, the busbar (1408) may be electrically coupled to the stator assembly (1402) and assist in the electrical conduction of current. The electric motor (1400) may include various bearings, including a bearing retainer (1412) and a roller bearing (1414). The bearing retainer (1412), roller bearing (1414), and shaft seal (1416) may be substantially aligned along a central axis. In some embodiments, the bearing retainer (1412) may assist in cooling as a cooling oil manifold. In some embodiments, the roller bearing (1414) may include a spherical shape. The electric motor (1400) may include a bearing screw (1410). The bearing screw (1410) may secure the bearing retainer (1414) to various components of the electric motor (1400), including the roller bearing (1414). In some embodiments, the stator housing (1418) may enclose the stator assembly (1402), roller bearing (1414), bearing retainer (1412), shaft seal (1416), and bearing screw (1410). The stator housing (1418) may have an interference fit or a press fit with the stator assembly (1402). For example, the stator housing (1418) may have a press fit with the stator lamination.In some embodiments, the stator housing (1418) may have a thermal restraint fit to the stator assembly (1402). For example, the stator housing (1418) may be a common housing that packages the components of the stator (1400) together, providing benefits including mass reduction and elimination of tubes, hoses, and other connectors. In some embodiments, the stator housing (1418) may include an oil container (1420) for collecting liquid used to cool or lubricate the electric propulsion system as described herein. Additionally, in some embodiments, additional components of the electric propulsion system may be present within the stator housing to provide additional mass reduction.

[0100] Figs. 15a-15c is a diagram of a stator assembly of a VTOL aircraft according to a disclosed embodiment. Fig. 15a illustrates a drawing of a stator core. In some embodiments, the stator (1500A) may include a wound stator assembly (1502A) and a copper winding (1504A). Fig. 15b It illustrates an additional drawing of the stator core (1500B). The lamination (1502B) can separate the copper winding (1504B). Fig. 15crepresents an example of a stator slot. For example, a stator core (1500C) may include a copper winding (1506C) that can be accommodated in a stator iron (1502C). A slot liner (1508C) may separate the copper winding (1506C) from the stator iron (1502C). The slot liner (1508C) may provide electrical insulation. The stator iron (1502C) may be contoured to fit a slot wedge (1504C), and the slot wedge (1504C) is located over the copper winding (1506C). The slot wedge (1504C) may hold the copper winding (1506C) in place from the stator iron (1502C). In some embodiments, the stator lamination may consist of the stator iron (1502C). Stator lamination can help insulate the core and reduce eddy currents or losses. In some embodiments, the stator assembly may include oil-filled cavities located around the stator to aid in cooling. These cavities may be fluidly coupled to a heat exchanger as described herein.

[0101] Figs. 16a-16c refers to similar elements of the rotor assemblies (1600A and 1600B) having similar numbers. Therefore, similar design considerations and configurations can be considered throughout the embodiments.

[0102] A disclosed embodiment of an electric motor assembly may include a rotor. In some embodiments, an electromagnetic field generated by a stator in the electric motor assembly may drive the rotation of the rotor about an axis.

[0103] Figs. 16a-16b is an exploded view and cross-sectional view of a rotor assembly of a VTOL aircraft according to a disclosed embodiment. Fig. 16aThis illustrates an exemplary exploded view of a rotor. The rotor assembly (1600A) may include a rotor (1602A) comprising a rotor hub (1604A). In some embodiments, the rotor hub (1604A) may be machined and constructed from aluminum. The rotor (1602A) may include a lamination (1606A) and a Halbach array (1608A). The lamination (1606A) may have a thermal interference fit to the rotor hub (1604A). The rotor (1602A) may be surrounded by a rotor overlap (1610A). In some embodiments, the rotor overlap (1610A) may be composed of carbon fiber. The Halbach array (1608A) may include magnets. The rotor overlap (1610A) may be adjacent to the Halbach array (1608A) and may apply pressure to the magnets of the Halbach array (1608A). In some embodiments, the rotor (1602A) may include a hollow portion. The hollow portion of the rotor may allow various motor assembly or gearbox assembly components to move through the rotor (1602A), thereby enabling a configuration in which components can be coupled to the rotor (1602A). In some embodiments, the electric motor assembly may be mechanically coupled to the gearbox assembly. The disclosed embodiments include various means for coupling the rotor and the sun gear. The rotor (1602A) may be mechanically coupled to the sun gear (1612A) and may be attached concentrically by various means for connecting and aligning components. The rotor (1602A) may be mechanically coupled to the sun gear (1612A) by various fastening means. For example, the rotor (1602A) may be secured to the sun gear (1612A) using a locking nut (1620A), a dowel pin, or a screw (1622A). The bearing (1616A) may have an interference fit with the rotor assembly (1602A) and the sun gear (1612A).In some embodiments, the sun gear (1612A) may include a gear tooth (1614A) that can be used in a gearbox assembly as described herein. The sun gear (1612A) may include a hollow center. In some embodiments, the sun gear (1612A) may be mechanically coupled to an oil sleeve (1618A) that can assist in the step of dispensing cooling or lubricating fluid using centrifugal force during rotation.

[0104] Fig. 16b... illustrates additional drawings of the rotor assembly (1600B). As described herein, the rotor (1602B) may include a rotor hub (1604B), a lamination stack (1606B), and a Halbach array (1608B). A rotor overlap (1610B) may be adjacent to the Halbach array (1608B) and surround the stator assembly (1602B). A bearing (1616A) may include an inner ring and an outer ring. In some embodiments, a sun gear (1612B) may be mechanically coupled to the rotor (1602B). Some embodiments may include the step of mechanically coupling the sun gear (1612B) and the rotor (1602B) using a screw (1622B). A bearing (1616B) may assist in the step of mechanically coupling the rotor (1602B) and the sun gear (1612B) by providing an interference fit. In some embodiments, the main shaft of the electric engine assembly may travel through the sun gear (1612B) and the rotor (1602B) via a bearing (1616B). Additionally, some embodiments may include a bearing (1616B) and a rotor hub (1604B) that function to support the rotor (1602B) with any load experienced by the rotor (1602B) or the rotor hub (1604A) during normal operation. In some embodiments, the inner surface of the rotor assembly (1602B) may have the same diameter as the outer ring of the bearing (1616B). The sun gear (1612B) may include gear teeth (1614B). In some embodiments, the rotor assembly (1612B) and the sun gear (1612B) may be substantially aligned along a central axis (1624B).

[0105] As described herein, disclosed embodiments of an electric propulsion system may include a motor assembly and a gearbox assembly. In some embodiments, the gearbox assembly may include a torque path that applies a load. As described herein, the electric propulsion system may include a rotor of the gearbox assembly and an electric motor assembly, both of which may apply a load to a shaft. For example, the rotational motion effect resulting from a rotating rotor in motion may apply a moment load. The moment load may be located on a centered path of the shaft. Since a gearbox assembly that may include planetary gears may share torque through multiple paths, the sharing of the load may vary depending on the tolerances of the components within the electric engine. Therefore, a solution that maintains a low mass and drag profile while supporting the load and resisting the moment created by the generated torque may be advantageous.

[0106] Fig. 54 This is a schematic diagram of an example electric motor assembly in a partial cross-sectional view. Fig. 54As illustrated in FIG. 54, the electric motor assembly (5400) may include a case (5402) that encloses a sealed environment (5404) with both a rotor (5406) ​​and a stator (5408) (and a magnet (5418) as part of the stator (5408)) within the case (5402). In some embodiments, the electric motor assembly (5404) may be positioned so that a propeller assembly (not shown in FIG. 54) driven by the electric motor assembly can drive air toward it to provide a cooling effect. Thus, the side (5410) facing the propeller assembly (i.e., facing the airflow driven by the propeller assembly) is the cool side; and the side (5412) not facing the propeller assembly (i.e., on the back side of the airflow generated by the propeller assembly) is the hot side. The airflow (5414) generated by the propeller assembly is used to cool the case (5402) so that the side (5410) facing the propeller can be made cool.

[0107] In some embodiments, as illustrated in FIG. 54, the rotor (5406) ​​can generate air movement (5416) inside a sealed environment (5404) enclosed by the case (5402) from the cool side (5410) toward the hot side (5412) to provide a cooling effect to one or more components outside the case (5402) on the hot side (5412). That is, heat generated by one or more components outside the case (5402) on the hot side (5412) is first dissipated to the cool side (5410) through the air movement (5416) inside the sealed case (5402), and then further dissipated by the air flow (5414) generated by the propeller assembly.

[0108] In some embodiments, the air movement (5416) may also provide a cooling effect to dissipate heat generated by the magnet (5418) inside the case (5402). The air movement (5416) facilitates heat dissipation from the magnet (5418) by the cooling effect generated by the air flow (5414).

[0109] Figs. 55a-55b is an illustration of exemplary inner surfaces of a portion of the rotor hub and a portion of the end plate. In some embodiments, the inner surfaces of the rotor hub (5500A) and the end plate (5500B), respectively (e.g., 5502A, 5502B), define an air path with less air resistance so that the rotor [is] case (5402)( Figs. 55a-55b To make it more efficient to generate air movement (e.g., 5416) inside (e.g., 5504A, 5504B), it may have fins (e.g., 5504A, 5504B).

[0110] Fig. 55a As illustrated in [Image], the pins (5504A) inside (5502A) of the rotor hub (5500A) may have different heights and shapes. In this exemplary embodiment, the pins of different shapes are all straight (i.e., flat) but may also have different geometric structures.

[0111] Fig. 55b As illustrated in [Image], the pins (5504B) inside (5502B) of the end plate (5500B) all have the same height. In this exemplary embodiment, the height of the pins (5504B) may be about 12 mm. Generally, this height may be about 5 mm to 20 mm.

[0112] In these exemplary embodiments, the pins of the rotor hub and stator may have a first clearance. The first clearance may be 0.4 mm to 1.2 mm or about 0.6 mm. The pins of the end plate and rotor may have a second clearance. The second clearance may be 0.4 mm to 1.2 mm or about 0.6 mm. The first and second clearances may be determined such that air inside a sealed environment (e.g., a case) is pressurized through the gap formed between the pins and the rotor, and the air is guided from the edge of the hot side toward the center of the motor on the hot side toward the center of the motor on the cold side.

[0113] Fig. 55c Is Fig. 54 This is the result of a simulation of the air velocity and pressure distribution inside the case, such as the case (5402). In the example illustrated in FIG. 55c, the blank space represents a solid motor structure in which no air is present. The different colors in the left drawing indicate a difference in air velocity, representing an air velocity between the rotor (5406) ​​and the motor arbor (5502B) that is substantially higher than the left side, thus indicating that the air inside the enclosed environment is agitated. In the middle drawing, the different colors illustrate the internal pressure distribution inside the enclosed environment (5404). In some embodiments, a larger pressure difference between the two points can generate a higher airflow with a higher velocity, which can increase the efficiency of heat exchange between the cool and hot sides of the case, thereby improving the cooling effect of the motor.

[0114] Fig. 55dis a set of exemplary inner surfaces of an end plate according to the disclosed embodiment. The end plate and the fins of the rotor may have different geometric structures and arrangements, and may be optimized by taking into account different design elements and operating parameters, such as rotational speed per minute (RPM), clearance, motor size, weight, rotational mass, and other design and operating parameters that may be influenced by the fin design and shape.

[0115] In some embodiments, the direction of the airflow may be reversed. For example, instead of having air moving toward the center of the hot side, the air may move from the center to the periphery of the hot side. In such embodiments, the airflow at the center of the motor will move from the hot side to the cool side. This can be achieved by changing the shape (e.g., curvature) of the fin. Fig. 24 It provides example designs of pin shapes, but the illustrated examples are not intended to limit the range of potential pin designs and shapes. Pin shapes may be optimized or modified according to the specific needs of the system and evaluation based on experiments and simulations.

[0116] The disclosed embodiment may include a bearing system comprising a rotor that utilizes a bearing to support a load. Fig. 16c[This section] illustrates a cross-sectional view of an exemplary embodiment of a rotor assembly according to an embodiment of the present disclosure. In some embodiments, the rotor assembly may include a bearing system (1600C). The bearing system (1600C) may include a rotor hub (1604C), a sun gear (1612C), and a main shaft (1626C). The bearing system (1600C) may use various types of bearings to reduce the load experienced by components substantially aligned along the shaft. As described herein, the rotor assembly may be mechanically coupled to the sun gear (1612C). The main shaft (1626C) may include an outer surface (1628C) that may be adjacent to a shaft flange assembly (1630C). The shaft flange (1630C) may be adjacent to a bearing (1634C). The bearing (1634C) may have an inner ring mechanically coupled to the main shaft (1626C) and an outer ring mechanically coupled to the rotor hub (1630C). In some embodiments, the bearing (1634C) may have an inner ring mechanically coupled to the main shaft (1626C) and an outer ring mechanically coupled to the sun gear (1612C) and the rotor hub (1630C). In some embodiments, the bearing (1634C) may be adjacent to both the rotor hub (1604C) and the sun gear (1612C). The bearing (1634C) may be mechanically coupled to the shaft flange assembly (1630C). As described herein, the bearing (1634C) may support the rotor hub (1604C) and support the load from the rotor hub (1604C). For example, the rotation and movement of the rotor hub (1604) may cause a rotational motion effect that exerts a load. The bearing (1634C) can support a load including a radial or axial rotor load. The bearing (1634C) can allow the sun gear (1612C) to rise so that changes in load can be absorbed. In some embodiments, the bearing (1634C) may be a rolling element bearing.For example, the bearing (1634C) may include a rolling element (1616C) that can be immersed in lubricating oil (1632C) within the bearing (1634C). In some embodiments, the lubricating oil (1632C) may include oil. Other bearings capable of supporting loads and high-speed rotation, such as ball bearings or deep groove ball bearings, may be used.

[0117] A disclosed embodiment of an electric propulsion system may include a pilot system for bearings to support a rotor. As disclosed herein, an electric propulsion system may include a sun gear and a bearing supporting a rotor. The bearing supporting the rotor may include a bearing having an outer ring mechanically coupled to the inner surface of the rotor. For example, the bearing (1634C) may include an outer ring mechanically coupled to a rotor hub (1604C). The bearing (1634C) may steer the sun gear (1612C) and the rotor hub (1604C) by guiding the alignment or coupling of various components. For example, the pilot may function to align or coupled the sun gear (1612C) and the rotor hub (1604C). The bearing (1634C) may support the edge of the sun gear (1612C) and the edge of the rotor hub (1604C) so as to be placed on the outer ring, which may attach the sun gear (1612C) and the rotor hub (1604C) concentrically. The first edge of the sun gear (1612C) and the first edge of the rotor hub (1604C) may meet and be adjacent to each other at the outer ring of the bearing (1634C). The bearing (1634C) may affect the diameter of the sun gear (1612C) and the rotor. The diameter of the outer ring of the bearing (1634C) may be substantially similar to the diameter of the inner surface of the sun gear (1612C) and the inner diameter of the rotor. In some embodiments, the rotor hub (1604C) and the sun gear (1612C) may be attached concentrically. The sun gear (1612C) may have the same diameter as the inner diameter of the rotor. In some embodiments, the pilot system for the bearing may include a shoulder. The shoulder may be an edge of a component adjacent to one or more edges of another component. For example, the shoulder may include a portion of a sun gear (1640B) adjacent to one or more edges of the bearing (1616B) and a portion of a rotor hub (1642B) adjacent to one or more edges of the bearing (1616B).Shoulders may cooperate to restrict the movement of the bearing. For example, shoulders may cooperate to restrict the movement of the bearing (1616B) axially along the shaft or along the axis (1624B). In some embodiments, the pilot may include shoulders to radially capture the bearing. The pilot system can reduce mass and avoid the need for additional material. In some embodiments, dowel pins may be used to control the sun gear and rotor.

[0118] In some embodiments, the rotor bearing system may also include a bearing to resist moment loads and allow the float to supplement the gearbox tolerances. The rotor bearing system may include a hydrodynamic bearing. The hydrodynamic bearing may resist or counteract the rotor moment load. In some embodiments, the hydrodynamic bearing may be located along the sun gear. For example, the hydrodynamic bearing may be located between the sun gear (1612C) and the main shaft (1626C), and the hydrodynamic bearing may be located along the length of the sun gear (1612C). In some embodiments, the hydrodynamic bearing may extend along the entire length of the sun gear (1612C). The hydrodynamic bearing may be located where the main shaft (1626C) has a shoulder or cavity as described herein. For example, the hydrodynamic bearing may contain fluid between the sun gear (1612C) and the shoulder or cavity of the main shaft (1626C). In some embodiments, the size or shape of the shoulder may be determined by the characteristics of the rotor. For example, the shoulder may have a depth and width that may be determined by the characteristics of the rotor, including mass, velocity, rate of change, and change of axis or load (including rotational motion, axial and radial loads or moments). The hydrodynamic bearing may contain a fluid, such as oil, located between the sun gear (1612C) and the outer surface (1628C) of the main shaft (1626C). The hydrodynamic bearing may assist in resisting the moment load experienced by the sun gear (1612C). For example, the hydrodynamic bearing may exert a restoring force to resist rotational motion loads. In some embodiments, the hydrodynamic bearing may contain oil. The hydrodynamic bearing may allow the sun gear (1612C) or ring gear to float. The hydrodynamic bearing may allow tolerances within various components of the electric propulsion system.Hydrodynamic bearings may contain the same fluid, such as oil, used throughout the electric propulsion system for lubrication and cooling. As discussed herein, a single fluid for hydrodynamic bearings, cooling, and lubrication can provide the advantage of reducing mass and the size of various components.

[0119] Fig. 50 The figure illustrates a perspective view of an exemplary rotor of a VTOL aircraft according to the disclosed embodiment. In some embodiments, the rotor (5000) may include a rotor hub (5002). The rotor hub (5002) may have layers (5004 and 5012). The rotor (5000) may be manufactured to include the rotor hub (5002) and the layers (5004 and 5012). The rotor (5000) may be made of aluminum, steel, or other material capable of transmitting torque to a propeller assembly. The rotor (5000) may be machined from a single material using various types of machines, such as a lathe, a computer numerical control ("CNC") machine, or any other type of machine capable of machining a rotor. The layers (5004, 5012) may be present on the rotor (5000) for the purpose of being later sacrificed to balance the rotor (5000). The rotor (5000) may be unbalanced due to manufacturing constraints, such as the precision of the machine, during the machining of the rotor. In some embodiments, the step of balancing the rotor (5000) may include the step of adding or removing mass from the rotor.

[0120] In some embodiments, manufacturing constraints in various regions of the rotor (5000) may determine the mass of the layer (5004, 5012). For example, the layer (5004, 5012) may have a specific minimum or maximum mass indicated by the manufacturing equipment and the step of creating the rotor. The layer (5004, 5012) may contain a mass of rotor material specified in a scale that corresponds to the manufacturing constraints present in each region of the rotor. In some embodiments, the mass of the layer (5004, 5012) may be determined based on the accuracy of the machine(s) manufacturing the various parts of the rotor so that it is later removed during the step of balancing the rotor. For example, in some embodiments, the machine or machines may manufacture a part of the rotor with an accuracy of + / - 5% of the target mass of the part of the rotor. In these examples, the rotor may include a layer (5004, 5012) having a total mass that is sufficient to be removed during the balancing step of the rotor to have a mass within the complex deviation mass due to the precision of the machine(s) manufacturing the rotor. In some embodiments, the material properties of the layer (5004, 5012) may include aluminum, steel, or other materials capable of accommodating the manufacturing precision of the machine(s) manufacturing part of the rotor. In some embodiments, the thickness or width and depth of the layer (5004, 5012) may be thicker or thinner depending on design considerations, system needs, and manufacturing constraints. In some embodiments, various layers may have substantially similar widths and depths, which includes a difference in width and depth of the layer that is less than 5% of the greater width and depth.

[0121] In some embodiments, the rotor (5000) may include multiple layers (5004, 5012). For example, the rotor (5000) Fig. 50As illustrated in the figure, a layer (5004) may be included at the edge or perimeter of the inner surface of the rotor hub (5002). In some embodiments, the rotor (5000) may have multiple layers (5004, 5012) located on opposite sides of the inner surface of the rotor or located next to each other along the inner surface, or may have any other configuration of layers (5004, 5012) along the rotor hub (5002). In some embodiments, layers (5004, 5012) may be located along the inner surface of the rotor at a distance from the edge of the rotor. Some embodiments may include layers at a substantially similar distance from the edge of the rotor. As used herein, a substantially similar distance may include a change in distance of less than 5% of the greater distance.

[0122] In some embodiments, the layers (5004, 5012) may include grooves (5006) that form a portion (5008). In some embodiments, the portion may be made of aluminum. Additionally, some embodiments may include grooves (5006) that may be made of aluminum. In some embodiments, the grooves (5006) may function as liquid channels for oil or other liquid present within the electric motor assembly. For example, in normal operation, as described herein, oil or liquid may be circulated throughout the electric motor assembly to assist in cooling or lubricating components. Thus, the grooves (5006) may function to allow oil or liquid to pass through the layers (5004, 5012) so that the oil or liquid does not accumulate within the layers (5004, 5012) but returns to an oil container or other reservoir as described herein. In some embodiments, multiple layers (5004) may be aligned so that the grooves (5006) of each layer are aligned.

[0123] In some embodiments, the rotor (5000) may include a through hole (5010). In some embodiments, the rotor (5000) may be machined into a through hole (5010). Those skilled in the art will understand that mass is an important factor in aircraft design, particularly in VTOL aircraft design. Mass can affect the efficiency, payload, and flight time of a VTOL aircraft. Accordingly, some embodiments of the rotor may include a through hole (5010) created by a machining process, a laser process, or any other process that removes mass from the rotor. The through hole (5010) can reduce the mass of the rotor (5000) by removing a section of the rotor hub (5002) material, such as aluminum. In some embodiments, the through hole may also function as a connection point for a sun gear as discussed above.

[0124] In some embodiments, as described herein, the electric motor assembly of a VTOL aircraft can generate torque by rotating the rotor (5000) at a high rotational speed. At high rotational speeds, an unbalanced rotor having a rotation axis that is not aligned with the center of mass of the rotor will experience a high degree of unwanted vibration and noise. An unbalanced rotor may result from production tolerances in the manufacturing process. For example, the magnets present in the rotor assembly may not have a uniform mass and may not be uniformly distributed along the rotor or lamination stack. Additionally, in some embodiments, through holes (5010) may be produced using a machining process, and production tolerances may result in an unbalanced rotor. Thus, it is confirmed that a process for balancing the rotor may be advantageous. It is also confirmed that mass can be an important design criterion in a VTOL aircraft, and therefore, traditional rotor balancing techniques involving steps of adding mass to the rotor or removing a minimum amount of mass may result in unwanted mass remaining in the rotor. In some embodiments, the process may be used to balance the rotor while achieving the maximum reduction in the mass of the rotor.

[0125] Some disclosed embodiments may include an improved process for balancing the rotor of an electric motor assembly. Some embodiments may include a step of identifying the rotation axis of the rotor. As discussed herein, the rotor (5000) may include layers (5004, 5012). In some embodiments, the layers (5004, 5012) function as sacrificial layers that can be processed to be integrated into the rotor so as to be removed from the rotor (5000) later to achieve a balanced rotor. In some embodiments, a portion (5008) may function as a sacrificial portion that can be processed into the rotor so as to be removed from the rotor (5000) later to achieve a balanced rotor. Removable layers and portions added to the rotor after it has been manufactured using fasteners, adhesives, or similar materials may function for purposes similar to sacrificial layers or portions. However, the removable layers and portions would require additional mass in the form of an add-on device that would not be beneficial to the overall efficiency of the VTOL. In addition, attachments used on removable layers and parts, such as fasteners and adhesives, pose a risk of falling off during flight and can damage other components of the electric propulsion system.

[0126] Some embodiments of the process for balancing the rotor may include a step of determining the imbalance present in the rotor by rotating the rotor about an axis of rotation. The step of determining the imbalance may include a step of rotating the rotor and a step of detecting the phase and individual magnitude of the imbalance. Some embodiments may include a step of marking the rotor by laser etching the rotor, placing individual stickers on the rotor, or creating a unique mark on the rotor by any other method. In some embodiments, the step of rotating the rotor may include a step of using a machine to rotate the rotor about an axis of rotation at a speed lower than the operating speed, such as a dynamic balancing device. The operating speed may include the expected rotational speed of the rotor for any flight phase. In some embodiments, the step of rotating the rotor may include a step of rotating the rotor at a speed lower than the first resonance of the rotor. The step of detecting the phase of the imbalance may include a step of using a machine to monitor the unique mark on the rotor while rotating. In some embodiments, the machine for monitoring the rotation of the rotor may be the same machine capable of rotating the rotor. The machine may track the unique mark and calculate the movement of the mark during rotation to indicate an unbalanced rotor. In some embodiments, the step of detecting the phase of the imbalance may also include the step of receiving a signal from an encoder or accelerometer during rotation or downloading after rotation to identify the force experienced by the rotor or the position of the rotor at a location where the encoder, accelerometer, or similar sensor is located on the rotor.

[0127] Some embodiments of the process for balancing the rotor may include a step of calculating the amount of mass to be added or removed at locations along the layers (5004, 5012) to correct an imbalance present in the rotor. Some embodiments may include a machine or algorithm that analyzes the phase and individual scale of the imbalance to determine the amount of mass to be added or removed and the locations where the mass is added or removed. In some embodiments, the machine calculating the mass to be added or removed may include a machine that detects the imbalance by rotating the rotor, or it may be a separate machine. In some embodiments, the mass to be added or removed at locations along the layers (5004, 5012) may change the center of mass of the rotor to coincide with the rotation axis of the rotor. In some embodiments, the rotor may have multiple layers (5004, 5012) located along the inner surface of the rotor at a distance from the edge of the rotor. Accordingly, the step of balancing the rotor may include a step of balancing the rotor between one or more planes of the rotor by adding or removing mass along one or more layers.

[0128] In some embodiments, the step of removing an amount of mass from the layer (5004, 5012) may include the step of processing a portion of the volume of the layer (5004, 5012). In some embodiments, the step of removing an amount of mass from the layer (5004, 5012) may include the step of removing 50% to 100% of the volume of the layer (5004, 5012). The step of removing 50% to 100% of the volume of the layer (5004, 5012) may reduce the mass of the rotor. In some embodiments, the layer (5004, 5012) may exist only to serve as a sacrificial material in the step of balancing the rotor. The layer (5004, 5012) may be fully formed into the rotor to provide an integrated rotor balancing material that is removed without being added. By removing the sacrificial rotor material, the balancing process will not require the use of adhesives or fastening methods to add counterweights.

[0129] In some embodiments, after removing material from the layer (5004, 5012), the amount of mass of the layer remaining in the rotor may be the minimum amount of mass required to balance the rotor, so a balanced rotor can be produced with the minimum mass. The step of removing most of the volume of the layer present in the rotor may reduce the mass of the rotor so that the rotor does not contain additional material. For example, if it is determined that a rotor with the layer (5004, 5012) is balanced without removing any part of the layer (5004, 5012), then 100% of the volume containing the layer (5004, 5012) may be processed, as no mass from the layer is required to balance the rotor. In some embodiments, it may be determined that 3% of the volume of the layer (5004) must be present in the rotor to balance it. In this example, 100% of the layer (5012) can be removed and 97% of the layer (5004) can be removed to balance the rotor.

[0130] Some embodiments may include a step of utilizing a specific machine to remove the volume of the layer (5004, 5012) during the step of balancing the rotor. Some embodiments may include a step of utilizing a machine capable of removing the volume of the layer (5004, 5012) with a precision of 0.01% to 0.1% of the layer. In some embodiments, a machine, such as a lathe or a CNC machine, may be used in the step of processing the volume of the layer at a resolution of less than 5 microns. In these embodiments, the step of using a machine capable of such precision can achieve the advantage of a balanced rotor having a minimum mass. Some embodiments may include a step of utilizing various types of machines when removing the layer, such as a step of removing a large portion of the mass to be removed in a manner having lower precision than a method for removing the remaining amount of mass to be removed.

[0131] Some embodiments may include a step of calculating the amount of mass to be added at a location along the layer (5004, 5012) to balance the rotor, and the step of balancing the rotor may include a step of processing the volume of the layer (5004, 5012) such that the amount of mass of the remaining layer is calculated to be added and is part of the layer (5004, 5012) equal to the amount of mass existing at the calculated location. In some embodiments, the step of calculating the amount of mass to be removed at a location along the layer (5004, 5012) to balance the rotor may include a step of processing the volume of the layer (5004, 5012) such that the amount of mass of the remaining layer is calculated to be removed and is part of the layer (5004, 5012) equal to the amount of mass existing at the calculated location and on the opposite side of the layer.

[0132] In some embodiments, the step of calculating the amount of mass to be removed may include the step of calculating the number of sacrificial parts (5008) to be removed. In some embodiments, the parts (5008) may be defined by the groove (5006). Some embodiments may include the step of removing the entire part (5008) or any portion of the part (5008). In some embodiments, the step of removing the parts (5008) may include the step of calculating the maximum amount of parts to be removed to achieve a balanced rotor. In some embodiments, the number of parts to be removed k Is k If any additional mass is removed after the part is removed, the amount of the part may be included such that the rotor can never achieve balance.

[0133] Fig. 51 The flowchart illustrates an exemplary process for balancing the rotors of a VTOL aircraft (5100) according to the disclosed embodiment. While the block diagram may be described below in relation to specific embodiments presented in other drawings, such embodiments are provided for exemplary purposes only and are not intended to be limited to the block diagram.

[0134] Fig. 51 The process includes process blocks (5102 to 5108). In block (5102), the process of balancing the rotor of the electric engine of the electric propulsion system may include the step of identifying the rotation axis of the rotor, and the rotor includes a sacrificial layer having a mass M formed along the circumference of the rotor in accordance with the discussion throughout the present disclosure.

[0135] In block (5104), the process of balancing the rotor of the electric engine of the electric propulsion system may include the step of determining the imbalance present in the rotor by rotating the root about the axis of rotation according to the discussion throughout the present disclosure.

[0136] In block (5106), the process of balancing the rotor of the electric engine of the electric propulsion system is positioned along the sacrificial layer such that the center of mass of the rotor coincides with the axis of rotation of the rotor, in accordance with the discussion throughout this disclosure. p Mass to add in k It may include a step of calculating the amount of.

[0137] In block (5108), the process of balancing the rotor of the electric engine of the electric propulsion system is, according to the discussion throughout this disclosure, the remaining mass n Mass from the sacrifice layer such that the amount of exists along the circumference of the rotor r It may include a step of removing the amount of.

[0138] As discussed herein, the rotor assembly of an electric motor assembly may include a rotor mechanically coupled to a sun gear. Similar to the above discussion regarding the step of balancing the rotor, it may be advantageous to balance the rotor assembly to avoid unwanted vibration and noise during normal operation. The rotor assembly may be unbalanced due to manufacturing tolerances and various coupled parts throughout the rotor assembly.

[0139] In some embodiments, the process of balancing the rotor assembly may include the steps of identifying the rotation axis of the rotor assembly and rotating the rotor assembly at a speed below the operating speed. In some embodiments, the rotor assembly may be coupled to a machine capable of rotating the rotor assembly at a speed below the operating speed. In some embodiments, the rotor assembly may be rotated at a speed lower than the first resonance of the rotor assembly. Some embodiments may include the step of determining an imbalance present in the rotor assembly. The step of determining an imbalance present in the rotor assembly may include the step of using a machine to identify the phase and magnitude of the imbalance by tracking a unique mark on the rotor assembly, such as a reflective sticker or a laser-etched mark, and using a photovoltaic cell, encoder, accelerometer, or similar component for tracking the motion of the rotor assembly.

[0140] Some embodiments may include a step of calculating the amount of mass to be added to the rotor assembly so that the center of mass of the rotor assembly coincides with the axis of rotation of the rotor assembly. The step of calculating the amount of mass and its individual parts may be performed using a machine or algorithm that analyzes the phase and magnitude of the imbalance in various planes of the rotor assembly to determine the amount and location of the mass to be added to the rotor assembly. In some embodiments, the mass to be added may be in the form of a rivet. The rivet may comprise a mass that can be attached removablely or permanently to a through hole (5010) of the rotor (5000). The rivet may be made of aluminum, copper, steel, or any other material capable of balancing the rotor assembly. The step of adding the rivet may include a step of attaching the rivet permanently or removablely to the rotor through the through hole so that the rotor assembly is balanced. In some embodiments, the amount of mass to be added may comprise rivets having different material properties and locations.

[0141] Fig. 52 illustrates another flowchart of an exemplary process for balancing a rotor assembly of a VTOL aircraft (5200). While the block diagram may be described below in relation to specific embodiments presented in other drawings, such embodiments are provided for exemplary purposes only and are not intended to be limited to the block diagram.

[0142] Fig. 52 As illustrated in [Image], the process can be started at block (5202) by identifying the rotation axis of the rotor, and the rotor includes a sacrificial layer having mass M formed along the circumference of the rotor in accordance with the discussion throughout the present disclosure.

[0143] In block (5204), the process of balancing the rotor assembly may proceed to the step of rotating the rotor about a rotation axis to determine the imbalance present in the rotor, in accordance with the discussion throughout the present disclosure.

[0144] In block (5206), the process of balancing the rotor assembly of the electric engine of the electric propulsion system is positioned along the sacrificial layer such that the center of mass of the rotor coincides with the axis of rotation of the rotor, in accordance with the discussion throughout this disclosure. p Mass to add in k It may include a step of calculating the amount of.

[0145] In block (5208), the process of balancing the rotor assembly is, according to the discussion throughout this disclosure, the remaining mass n Mass from the sacrifice layer such that the amount of exists along the circumference of the rotor r It can proceed to the step of removing the amount of.

[0146] In block (5210), the process of balancing the rotor assembly may proceed to the step of identifying the rotation axis of the rotor assembly, and the rotor assembly comprises a rotor mechanically coupled to a sun gear according to the discussion throughout the present disclosure.

[0147] In block (5212), the process of balancing the rotor assembly may proceed to the step of rotating the rotor about a rotation axis to determine the imbalance present in the rotor assembly, in accordance with the discussion throughout the present disclosure.

[0148] In block (5214), the process of balancing the rotor assembly is to add a number of rivets to the rotor assembly so that the center of mass of the rotor assembly coincides with the axis of rotation of the rotor assembly according to the discussion throughout this disclosure. j It can proceed to the step of calculating.

[0149] In block (5216), the process of balancing the rotor assembly of the electric engine of the electric propulsion system is, according to the discussion throughout this disclosure, to the rotor assembly j It may include the step of adding several rivets.

[0150] As described herein, disclosed embodiments of an electric propulsion system may include a gearbox assembly. The gearbox may assist in gear reduction for the electric propulsion system. As described herein, some embodiments of an electric propulsion system may include a gearbox assembly located between an electric motor assembly and an end bell assembly. The gearbox assembly may include a main shaft assembly.

[0151] Fig. 17[Image] is an exploded view of a main shaft assembly of a VTOL aircraft according to a disclosed embodiment. The main shaft assembly (1700) may include a main shaft (1702), a carrier cover (1714), a planetary gear (1704), a pump drive gear (1716), and a planetary carrier (1712). The main shaft assembly (1700) may include a compound planetary gear so that the planetary gear (1704) is mechanically coupled to the planetary gear (1706). In some embodiments, shafts (1708 and 1710) may extend from the planetary gear (1704). In some embodiments, shafts (1708 and 1710) may extend from the first planetary gear (1704) and the second planetary gear (1706), respectively. The planetary gear (1704) may be connected to a sun gear and a ring gear via an interface. In some embodiments, the ring gear may be fixed. In these embodiments, the planetary gear (1704) that interfaces with the ring gear and the sun gear can rotate relative to the sun gear. In some embodiments, the planetary gear (1706) can interface with the ring gear. In these embodiments, the planetary gear (1704) can interface with the sun gear, while the planetary gear (1706) interfaces with a fixed ring gear that drives the sun gear to rotate the planetary gears (1704 and 1706) relative to the sun gear. When the planetary gear and the corresponding shaft (1710) rotate around the circumference of the sun gear, the planetary carrier (1712) can be mechanically coupled to the planetary gears (1704 and 1706) via the shaft (1710) or the like so that the planetary carrier (1712) rotates at the same speed. The planetary carrier (1712) can be mechanically coupled to multiple planetary gears (1704 and 1706). In some embodiments, when the planetary gear and the corresponding shaft (1708) rotate around the circumference of the sun gear, the carrier cover (1714) may be mechanically coupled to the planetary gears (1704 and 1706) through the shaft (1708) and the like so that the carrier cover rotates at the same speed.

[0152] In some embodiments, the main shaft assembly (1700) may include a planetary carrier (1712) having a bearing (1722) to assist the planetary carrier (1712) in receiving the shaft (1710). The bearing (1722) may allow the shaft (1710) to be received within the planetary carrier (1712) while rotating the shaft (1710) with the planetary gears (1704, 1706). In some embodiments, the carrier cover (1714) may have a bearing (1718) to assist the carrier cover (1714) in receiving the shaft (1708) so that the shaft (1708) is received within the carrier cover (1714) while rotating the shaft (1708) with the planetary gears (1704, 1706). In some embodiments, washers (1720, 1724) may be positioned between the planetary gear (1704, 1706), the carrier cover (1714), and the planetary carrier (1712), respectively. Washers (1720, 1724) may be designed to provide a surface to the planetary gear (1704, 1706) for opposing rotation without taking into account mechanical tolerances in the manufacture of components of the entire gearbox assembly or without damaging the planetary carrier (1712) or the carrier cover (1714). Some embodiments may include the step of mechanically joining the planetary carrier (1712) and the carrier cover (1714) using a screw (1728) or a similar component.

[0153] In some embodiments, the carrier cover (1712) may be mechanically coupled to the main shaft (1702). In these embodiments, the rotation of the main shaft will be at the same speed as the carrier cover and at the same speed as the planetary gear (1704) or the compound planetary gear (1704 and 1706). In some embodiments, the planetary carrier may be mechanically coupled to the main shaft (1702). In these embodiments, the rotation of the main shaft will be at the same speed as the planetary carrier (1712) and at the same speed as the planetary gear (1704) or the compound planetary gear (1704 and 1706).

[0154] In some embodiments, the main shaft assembly (1700) may include a pump drive gear (1716). The pump drive gear may be positioned between a planetary carrier (1712) and a carrier cover (1716). Additionally, in some embodiments, the pump drive gear (1716) may be positioned between several planetary gears, including a compound planetary gear (1704, 1706). The pump drive gear (1716) may be mechanically coupled to various components present within the gearbox assembly, including the planetary carrier (1712), planetary gears (1704, 1706), or the carrier cover (1714). The pump drive gear (1716) may be connected via an interface with other components not shown herein within the electric engine assembly to circulate oil or other coolant liquid throughout the liquid path to cool and lubricate components present within the electric engine assembly, as described herein. For example, the pump drive gear (1716) may be connected via an interface with the pump gear acting to draw liquid from the oil tank to the heat exchanger. In this embodiment, the rotational speed of the pump drive gear (1716) may determine the speed at which oil or other liquid circulates throughout the electric engine assembly. In some embodiments, the pump drive gear (1716) may be mechanically coupled to the main shaft (1702) so that the pump drive gear rotates at the same speed as the main shaft (1702). In some embodiments, the main shaft assembly (1700) may include a dowel pin (1726) or a similar alignment component that functions to align the pump drive gear with various components of the main shaft assembly (1700), including a planetary carrier (1712) or a carrier cover (1714).

[0155] As described in this specification, an electric motor assembly can drive the rotation of a rotor. The rotation of the rotor, which can be mechanically coupled to a sun gear, can rotate the sun gear at the rotor speed. The sun gear rotating at the rotor speed may interface with a planetary gear (1704) or a compound planetary gear (1704 and 1706) to generate an output of a gearbox assembly containing a new value of torque to be supplied to the propeller assembly. In some embodiments, as described in this specification, a combination using a sun gear, a planetary gear including a compound planetary gear, and a ring gear can produce a gear reduction. Those skilled in the art will understand that the gear ratio can be calculated from the gears present in the gearbox assembly. Thus, the characteristics of the gears within the gearbox assembly can determine the possible gear reduction in an electric propulsion system. In some embodiments, since a specific value of torque to be applied to the propeller assembly may be required for the aircraft to achieve lift provision for the payload, the gear reduction value may be a relevant design criterion for a VTOL aircraft. However, it should be understood that increasing the gear size to produce a greater gear reduction may result in an increase in the electric engine drag profile and mass. Accordingly, as described herein, the embodiments can provide an electric propulsion system design optimized in terms of drag profile and mass versus payload capability.

[0156] As described in this specification, an embodiment of the gearbox assembly may include a sun gear. Fig. 18[Image] is an illustration of an exemplary sun gear of a VTOL aircraft according to a disclosed embodiment. The sun gear (1800) may be composed of stainless steel, plastic, or any material capable of assisting in gear reduction. The sun gear (1800) may include teeth (1802) to assist in gear reduction. Some embodiments may include spline teeth. In some embodiments, the gear teeth (1802) may interact with planetary gears. The sun gear (1800) may include a hollow center. In some embodiments, components of the gearbox may move through the hollow portion of the sun gear (1800). The sun gear (1800) may also include through holes (1804) to assist in the step of securing the sun gear (1800) to other components of the electric engine. In some embodiments, the sun gear (1800) may be mechanically coupled to other components of the electric engine assembly, such as the rotor or output shaft of the electric motor assembly. Some embodiments may include a through hole (1804) that allows for such mechanical coupling. In some embodiments, the sun gear (1800) may be fixed and thus may not rotate. In these embodiments, the planetary gear and ring gear may rotate freely. Some embodiments may include a through hole (1804) fixed to another component or surface to restrict the rotation of the sun gear (1800).

[0157] An embodiment of the gearbox may include a ring gear. Fig. 19[Image] is an illustration of an exemplary ring gear of a VTOL aircraft according to a disclosed embodiment. The ring gear (1900) may include teeth (1902). The teeth (1902) may interface with one or more planetary gears to assist in gear reduction. The ring gear (1900) may be fixed or freely rotatable. A fixed ring gear is fixed so that the planetary gear can rotate around the sun gear. In some embodiments, the ring gear may be fixed by using through holes (1904) to connect the ring gear to various components or structures within an electric propulsion system. In other embodiments, the free ring gear may rotate around a fixed planetary gear or a fixed sun gear. The ring gear (1900) may include slots (1902) to assist in fixing or mechanical connection.

[0158] As described in this specification, an embodiment of the gearbox assembly may include a planetary carrier assembly. Fig. 20[Image] is a diagram of an exemplary carrier assembly of a VTOL aircraft according to the disclosed embodiments. In some embodiments, the carrier assembly (2000) may include a planetary carrier (2008), a first planetary gear (2006), a pump drive gear (2012), a second planetary gear (2004), and a carrier cover (2010). In some embodiments, the planetary carrier (2008), the first planetary gear (2006), the pump drive gear (2012), the second planetary gear (2004), and the carrier cover (2010) may rotate about a central axis (2016) or a shaft (2002). One or more planetary gears of the carrier assembly (2000) may be substantially aligned along a shaft (2014) or a central axis (2018) to form a set of compound planetary gears. For example, the first planetary gear (2006) and the second planetary gear (2004) may share a shaft (2014) and be coaxial along a central axis (2018). The carrier assembly (2000) may include a shaft (2002). The shaft (2000) may be coaxial along a central axis (2016). In some embodiments, the planetary carrier (2008), the first planetary gear (2006), the pump drive gear (2012), the second planetary gear (2004), the carrier cover (2010), and the shaft (2002) may be mechanically coupled so that all components rotate at the same speed. In some embodiments, the shaft (2002) may be mechanically coupled to the propeller assembly so that the shaft transmits torque or mechanical axial power to the propeller assembly. In some embodiments, the carrier assembly (2000) may include a cavity, port, or hole to help distribute a coolant, such as oil.

[0159] In some embodiments, the electric engine may include an inverter assembly. The inverter assembly may include a circuit network configured to receive a direct current input, convert the direct current into alternating current, and provide the alternating current to the stator ring of the electric motor.

[0160] As disclosed herein, embodiments of an electric engine assembly may include a thermal management system or a cooling system capable of circulating coolant or lubricating oil throughout the engine. Lubricating oil or coolant, such as oil, may be present in an oil tank and distributed to components throughout the electric engine assembly. As disclosed herein, oil may move from the oil tank to a heat exchanger and to various locations within the electric engine assembly, including an inverter assembly, a gearbox assembly, and an electric motor assembly. As described herein, the electric motor assembly may include an end bell assembly. In some embodiments, the end bell assembly may be adjacent to the inverter assembly.

[0161] Figs. 21a-21b is a diagram of an exemplary end bell assembly of a VTOL aircraft according to a disclosed embodiment. Fig. 21aThe figure illustrates an internal view of the end bell plate of the end bell assembly. The end bell plate (2100A) may include a plate (2102A) made of aluminum, steel, or other types of thermally conductive material. The end bell plate (2100A) may include a pump rotor (2104A) and a passage rotor (2106A). The passage rotor (2106A) may be sized so that the pump rotor (2104A) can rotate within the passage rotor (2106A), and that multiple areas are open around the pump rotor (2104A) while the pump rotor (2104A) rotates within the passage rotor (2106A). The pump rotor (2104A) may be located within the passage rotor (2106A). The pump rotor (2104A) may have rotation driven by being mechanically coupled to other components of the electric engine assembly, such as a pump gear (2114B). In some embodiments, the pump rotor (2104A) and the passage rotor (2106A) may correspond to a zero-rotor or positive displacement pump having an inner and outer rotor. The pump rotor (2104A) may circulate oil from the oil tank through the pump inlet (2116B). In some embodiments, the pump rotor (2104A) may rotate within the passage rotor (2106A) to draw oil from the pump inlet through an open area between the pump rotor (2104A) and the passage rotor (2106A). In some embodiments, the rotation of the pump rotor (2104A) within the passage rotor (2106A) may create a vacuum between the pump inlet (2116B) and the oil tank containing any liquid. The pump outlet (2118A) is such. For example, the pump may create a vacuum to draw oil from the oil tank to the pump inlet (2116B).In some embodiments, as described herein, a pressure difference may exist between the pump outlet (2118A) and various distribution points of the cooling system so that oil or other liquid can be drawn through the cooling system from the opening between the pump rotor (2104A) and the passage rotor (2106A) to the pump outlet (2118A). In some embodiments, the end bell plate (2100A) may include additional or different components, such as an electric pump or other mechanical configuration, for drawing oil or other liquid through the pump inlet (2116B). After entering through the pump rotor (2104A) and the passage rotor (2016A), the oil or liquid may move in the direction (2120A) and move to the heat exchanger at the pump outlet (2118A). In some embodiments, the heat exchanger may be mounted on the heat plate (2100A) or the separator plate as discussed herein.

[0162] In some embodiments, the heat exchanger may cool oil or other liquid used to lubricate or cool the inverter assembly, gearbox assembly, and / or electric motor assembly. In some embodiments, a specific portion of the cooled oil or liquid exiting the heat exchanger may be directed to the inverter assembly to cool these components, or to the motor-gearbox housing to cool components of the gearbox assembly and / or electric motor assembly. Some embodiments may include different distributions of the cooled oil or liquid among the inverter assembly versus the gearbox assembly and electric motor assembly. For example, the inverter assembly may receive 40% of the volume of the cooled oil, and the motor-gearbox housing may receive 60%. The ratios may vary depending on the design considerations and requirements of the specific implementation. In practice, different types of electric propulsion systems may use different fluid distribution ratios as described herein. Additionally, it should also be understood that tilter electric propulsion systems and lifter electric propulsion systems may have similar or dissimilar distributions of oil from the heat exchanger. The pump corresponding to the pump rotor (2104A) and pump gear (2114B) can provide performance improvements to the gearbox assembly. Additionally, by using the pump to drive oil transport to the gearbox assembly and electric motor assembly as well as to the inverter assembly, additional components for transporting coolant to the inverter assembly may not be required. These advantages can reduce mass and improve the drag profile of the electric propulsion system.

[0163] From the heat exchanger, cooled oil may enter a channel (2108A) and move to an annulus (2110A) in the direction (2114A). The annulus (2110) may be aligned along a shaft as described herein. The annulus (2110A) may include a port (2116A). Oil from the channel (2108A) may move through the port (2116A) to various components of an electric engine, including a gearbox assembly and a motor assembly, to provide cooling and lubrication. Oil may also move from the annulus (2110A) to a channel (2112A). The end bell plate (2100A) may also include a port (2122A) to allow oil or other liquid to be delivered through the end bell assembly (2100B). In some embodiments, the pump may generate pressure capable of driving the movement of liquid through the end bell plate (2100A). For example, pressure from the pump, which may be a zero-rotor or positive displacement pump, may drive the movement of oil in the channels (2108A, 2112A), annulus (2110A), port (2116A), or other grooves or cavities of the end bell plate that may help transport the liquid.

[0164] Fig. 21bThe drawing illustrates an example end bell assembly. The end bell assembly (2100B) may include an end bell plate (2100). Additionally, as described herein, the end bell assembly may include a gear that can be driven by or interact with an additional gear in the gearbox assembly. In some embodiments, a ring gear (2104B) may be coupled to the end bell plate (2102B) assembly. The ring gear (2106B) may include a tooth that can be interfaced with an additional gear. As described herein, the tooth of the ring gear (2106B) may interact with a planetary gear of the main shaft assembly. In some embodiments, the tooth of the pump drive gear may be interfaced with the tooth of the pump gear (2114B) so that the rotation of the pump drive gear drives the rotation of the pump gear (2114B). The pump gear (2114B) may be mechanically coupled to the pump rotor (2104A) so that the rotation of the pump gear (2114B) can drive the rotation of the pump rotor (2104A). Consequently, the pump gear (2114B) can drive the transport of lubricating oil or coolant throughout the end bell assembly. In some embodiments, the pump gear (2114B) can drive lubricating oil or coolant from an oil tank. The end bell (2102B) may include a port (2118B) for draining oil from a heating plate through a port (2122A).

[0165] In some embodiments, the end bell assembly (2100B) may include an end bell plate (2102B) that functions to seal an electric motor assembly housing or a motor-gearbox assembly housing. In some embodiments, the end bell assembly (2100B) may include a first circular wall extending from the end bell plate (2102B). In some embodiments, as described herein, the ring gear (2106B) may be coupled to the first circular wall (2104B) so that the ring gear (2106B) does not rotate freely. In some embodiments, the end bell assembly (2100B) may include a second circular wall (2108B) extending from the end bell plate (2102B). In some embodiments, the second circular wall (2108B) may have a diameter less than the diameter of the first circular wall (2104B). The second circular wall (2108B) may accommodate a bearing (2110B). In some embodiments, the bearing (2110B) may be mechanically coupled to a shaft including a main shaft capable of transmitting mechanical axial power to a propeller assembly. In some embodiments, the bearing (2110B) may include a groove to assist in the delivery of oil or other liquid. The second circular wall (2108B) may also include an annulus including a port hole (2112B). The port hole (2112B) may be aligned with a port (2116A) to receive oil or liquid from a heat exchanger. The port hole (2112B) may include a supply of oil or other liquid to cool or lubricate components of the electric motor assembly and gearbox assembly.

[0166] In some embodiments, the port hole (2112B) may deliver oil or other liquid to the main shaft. In some embodiments, the outer surface of the main shaft may function as a liquid channel through which oil or other liquid flows over the main shaft and may be distributed to components within the gearbox assembly and / or electric motor assembly.

[0167] A disclosed embodiment of an inverter assembly may include an inverter assembly having a heat exchanger. Fig. 22 [Image] is a diagram of an exemplary carrier assembly of a VTOL aircraft according to the disclosed embodiment. In some embodiments, the inverter assembly (2200) may include an inverter assembly housing (2202) coupled to a heating plate (2204). The inverter assembly housing (2202) may function to accommodate an inverter assembly component as discussed herein. The inverter assembly housing (2202) and the inverter assembly (2200) may have a substantially circular profile. As used herein, the profile may be substantially circular, having a length of a short axis and a length of a long axis, wherein the length of the short axis is at least 80% of the length of the long axis.

[0168] In some embodiments, the inverter assembly (2200) may include a high-voltage connector (2212) and a low-voltage connector (2210). The high-voltage connector (2212) may have a low profile. The high-voltage connector (2212) may receive high-voltage power from a high-voltage power system located elsewhere within the aircraft via a high-voltage channel. The inverter assembly (2212) may include at least one drain (2208). The drain (2208) may be configured to allow any oil or liquid present within the inverter assembly to exit the inverter assembly (2200) regardless of the orientation of the electric engine assembly. In an alternative embodiment, the inverter assembly (2200) may also include a vent. In some embodiments, the inverter assembly (2200) may include a heat exchanger (2206) coupled to or mounted on a heat plate (2204). In some embodiments, the heat exchanger (2206) may be an integrated heat exchanger. In some embodiments, the heat plate (2204) may be welded to the heat exchanger (2206). For example, the heat plate (2204) may be made of aluminum. The assembly of the heat plate (2204) and the heat exchanger (2206) may include brazing, quenching, aging, and welding. In some embodiments, the heat plate (2204) and the heat exchanger (2206) may be processed from the same material.

[0169] FIG. 56a is a diagram illustrating a cross-sectional view of a press-in mesh port after installation when operated in an inclined position according to a disclosed embodiment. In some embodiments, Fig. 23 An inverter housing such as the housing (2302) shown in is Fig. 23 It may have multiple drains and / or vents, such as the drain / vent (2208) shown in the figure. Fig. 56aAs illustrated in [Figure], each drain and / or vent (5600) may include a press-in mesh drain and vent port (5602). Each port (5602) may include a mesh (5604) and a press-fit lock (5606) in the mesh (5604). The press-fit lock (5606) is inside the inverter housing (5608) ( Fig. 56a It may be configured to be pressurized (partially shown in the image) and maintained at an angle of 0° to 90°. In some embodiments, these angles may be considered for manufacturing difficulties. In some embodiments, the mesh (5604) material may be aluminum, copper, titanium, stainless steel (as used in sintered metal type mesh), or any mesh material having a coefficient of thermal expansion (CTE) that matches the material of the housing (2302) (e.g., aluminum). In some embodiments, the drain and / or vent (5600) is located along the perimeter of the inverter housing (5608) so that the inverter housing (5608) can be discharged through at least one plurality of drain and / or vent (5600) regardless of the orientation of the inverter housing (5608).

[0170] In some embodiments, the inverter housing (5608) is Figs. 32a-32d It may have lifter positions and tilter positions corresponding to the scenarios described separately.

[0171] In some embodiments, the size of the port (5602) can be adjusted to suit the application needs. Fig. 56b is a drawing illustrating a cross-sectional view of a press-in mesh port after installation when operated in an inclined position according to a disclosed embodiment. In some exemplary embodiments, Fig. 56b As shown in the figure, the hole size may be about 3 mm, and after installation, the angle of inclination may be 10° to 25° or up to 35° with respect to the direction of gravity.

[0172] Some embodiments may include an inverter assembly, and the components of the inverter may be adjacent to each other and share a common housing. In some embodiments, the components of the inverter assembly may be placed on top of each other in a stacking direction. In some embodiments, the components of the inverter assembly may be substantially aligned along a central axis. The inverter assembly may include various components for sensing, networking, and control. Fig. 23 [Image] is an exploded view of an inverter assembly of a VTOL aircraft according to a disclosed embodiment. The inverter assembly (2300) may include a control printed circuit board assembly (“PCBA”) (2316), a spacer plate assembly (2314), a gate drive PCBA (2312), a capacitor assembly (2310), a power PCBA (2324), a housing gasket (2308), a heat plate assembly (2304), and a heat exchanger (2306). The components (2300) of the inverter assembly may be mechanically joined by various fastening methods. For example, the components of the inverter assembly (2300), including the inverter assembly housing (2302), may be fastened to each other by fasteners (2318). Additionally, the inverter assembly (2300) may include an inverter assembly housing (2302) that can be coupled to a heating plate assembly (2304) to surround the inverter assembly components and protect them from any liquid, debris, or other substances that may be harmful to the inverter assembly components. The inverter assembly housing (2302) may include connections for power and current used by components of the inverter assembly (2300), such as a high-voltage connector (2322) and a low-voltage connector (2320). In some embodiments, the inverter assembly housing (2302) may include an inverter busbar for high current and low inductance.

[0173] In some embodiments, the inverter assembly housing (2302) may be cylindrical in shape or may have a donut-like shape (i.e., a round whole shape with a center hole in the plane). The form factor of the inverter assembly housing (2302) may provide low drag during flight.

[0174] In some embodiments, the capacitor assembly and at least one PCBA (e.g., 2312, 2314, 2316) may all be stacked and located inside the inverter housing (2302). In some embodiments, each stacked component (e.g., PCBA (2316), spacer plate assembly (2314), gate drive PCBA (2312), capacitor assembly (2310), housing gasket (2308), heat plate assembly (2304)) may have a plurality of through-positioning holes so that a passing fastener (2318) secures the stacked structure. In some embodiments, the fastener (2318) may be a long screw, bolt, or rod.

[0175] In some embodiments, a set of alignment pins (2326) can facilitate alignment of components stacked on the inverter assembly (2310) (e.g., PCBA (2316), spacer plate assembly (2314), gate drive PCBA (2312), capacitor assembly (2310), housing gasket (2308), heat plate assembly (2304)). In some embodiments, the alignment pins (2326) may be integrated with the housing of the capacitor assembly (2310). Alternatively, in some embodiments, the positioning pins (2326) may be separate components from the assembly. In some embodiments, the positioning pins (2326) may be overmolded as a feature of the housing of the capacitor assembly (2310).

[0176] In some embodiments, the heat plate assembly (2304) may have a set of receptacles for alignment pins (2326). The number of receptacles may correspond to the number of alignment pins (2326).

[0177] Fig. 60a This is a diagram of a capacitor housing showing alignment pins according to an exemplary embodiment. Fig. 60b Figure 23 is an illustration of a heat exchanger and a heat plate showing a coupling alignment pin according to a disclosed embodiment. In this exemplary embodiment, two alignment pins (6002A and 6002B) may be overmolded as a feature of the housing (6000A) of a capacitor assembly (e.g., 2310). In the heat plate (6000B) (e.g., 2304 in FIG. 23), the two receptacles (6004A and 6004B) may have different shapes. The first receptacle (6004A) may have a circular shape configured to provide a frictional coupling to the first alignment pin (6002A). The second receptacle (6004B) may have an elongated shape (e.g., a long elliptical shape, a slot, etc.) to accommodate dimensional tolerances. The major axis of the elongated shape may have a radial direction.

[0178] In some embodiments, the alignment pins (6002A and 6002B) may extend bidirectionally from both sides of the capacitor housing (6000A). In the assembly process, the capacitor assembly (e.g., 2310 in FIG. 23) may be positioned on top of the heat plate (6000B) (e.g., 2304 in FIG. 23) through the housing gasket (e.g., 2308 in FIG. 23) and the power PCBA (e.g., 2324 in FIG. 23). The lower surface of the first alignment pin (6002A) is coupled with the first receptacle (6004A), and the lower surface of the second alignment pin (6002B) is coupled with the second receptacle (6004B). The two pairs together form a capacitor assembly (e.g., Fig. 23 2310) and heating plate (6000B) (e.g., Fig. 23A guide can be provided for aligning the 2304). The upper surface of the alignment pins (6002A and 6002B) then provides material to the rest of the components of the inverter assembly (e.g., PCBA (2316), spacer plate assembly (2314), gate drive PCBA (2312), capacitor assembly (2310), housing gasket (2308), and heat plate assembly (2304) of FIG. 23). Each of these components may have through alignment holes for the alignment pins (6002A and 6002B) to pass through. These holes may have a similar arrangement or a loose fit to the receptacle of the heat plate (6000B) for reasons of tolerance allocation. After all components are laminated, a fastener (2318) may be applied to tighten the components together. In some embodiments, the receptacle (6006) may receive the fastener (2318). The receptacle (6006) may be threaded, press-fit, or have a crush rib depending on the type of fastener (2318).

[0179] Fig. 23 Referring again to the above, in some embodiments, the stacking direction of the housing may follow various design shapes, such as a circular shape having a diameter proportional to the diameter of the motor or gearbox or any other design shape. The internal components of the inverter may be arranged to help achieve the design target shape. In some embodiments, the stacking direction may be achieved by using common structural components through the stack, such as designing stacks of different levels, so that a common structure, such as various bolts of the same length, can pass through each level to create the stacking direction.

[0180] In some embodiments, the use of a stacking orientation can create additional obstacles to further design considerations, such as heat transfer, where the difficulty of managing proper coolant distribution may increase in these configurations. Additionally, the use of long bolts to move through various levels of the inverter can increase vibration and shock experienced by the inverter assembly. However, it should also be understood that this stacking orientation can be advantageous when considering various design considerations. For example, allowing a stacking orientation can be advantageous from an aerodynamic perspective, enabling the inverter, or the inverter combined with other engine components such as gearboxes and / or motors, to maintain a low drag profile. Furthermore, the stacking orientation is advantageous from a manufacturability perspective, allowing fewer components to be included in the stage protecting the inverter assembly, as well as from a mass reduction perspective, where fewer components and potentially less mass are used to protect the components.

[0181] In some embodiments, the capacitor assembly (2310) may have at least one capacitor in a capacitor housing having at least one busbar on the outside. The capacitor assembly (2310) may have a center hole and a plurality of through-positioning holes in the capacitor housing. The capacitor assembly (2310) may have at least one PCBA located inside the capacitor housing.

[0182] As disclosed in this specification, the inverter assembly may include a power PCBA assembly. In some embodiments, the power PCBA may include a switchboard. Fig. 24is an illustration of an exemplary printed circuit board assembly of a VTOL aircraft according to the disclosed embodiment. The switchboard (2400) may also include a sensor assembly. For example, possible sensors may include sensors for a current shunt, motor temperature, and MOSFET module temperature. Additionally, some embodiments may include various power modules (2402) electrically coupled to the switchboard (2400). As discussed herein, the power modules (2402) generate heat during use and may require cooling to ensure the functionality and efficiency of the overall electric propulsion system.

[0183] Fig. 57 is a cross-sectional perspective view of an integrated sensor of a switchboard according to some embodiments of the present disclosure. In some embodiments, the switchboard may be one of at least one PCBA of an inverter assembly (2300).

[0184] In some embodiments, the switchboard (5702) may have a sensor integrated therein. In some embodiments, the switchboard (5702) may have a rotor position sensor integrated therein. In some embodiments, the rotor position sensor may have at least two Hall sensors (5704) integrated therein ( Fig. 57 (Only one may be shown.) In some embodiments, the gearbox of the propeller assembly may have a magnet on the planetary carrier. The switchboard (5702) and the gearbox (5706) are positioned close to each other so that at least two Hall sensors (5704) can detect the position of the magnet to determine the position of the propeller. In some embodiments, the heating plate (2304) of the inverter assembly (2300) and the end bell plate of the gearbox (5706) are made of a material that does not block the magnetic field so that at least two Hall sensors (5704) can detect the position of the magnet.

[0185] In some embodiments, the switchboard (5702) may have an oil temperature sensor (not shown) integrated therein. In some embodiments, the oil temperature sensor may be positioned to detect the temperature of a cooling fluid (e.g., oil, water, or other fluid or mixture of fluids known to have a large heat capacity). In some embodiments, the cooling fluid may be used to cool a MOSFET, a power module, or other components that generate heat.

[0186] In some embodiments, the distribution board (5702) may have an auxiliary speed sensor (not shown) connected to the control panel of the electric propulsion system (not shown) to provide spare parts.

[0187] Fig. 58 is a perspective view illustrating a flexible PCBA connection according to a disclosed embodiment. In some embodiments, the PCBA (5800) may have a flexible PCBA structure (5802) that extends out of the PCBA plane to make an electrical connection with an electrical component (not shown). In some embodiments, the flexible PCBA (5802) may include a contact pad (5804) having an electrical contact (not shown) with it and at least one bent connection (5806) formed by cutting a laminated printed circuit board (PCB). The electrical contact may be electrically connected to an electronic device in the remainder of the PCBA through at least one of the at least one bent connection (5806).

[0188] In some embodiments, each bent connection (5806) may have a flex factor. The flex factor is defined as the permissible movement or deflection of the contact pad over the length of the flexible section (i.e., the bent connection (5806) and the contact pad (5804)). The flex factor may be defined for movement along any direction, namely, a direction within the plane defined by the PCBA, a direction perpendicular to the plane defined by the PCBA, or any direction between the two aforementioned directions. In some embodiments, when the contact pad (5804) changes direction out of the plane defined by the PCBA, the flex factor serves as an indicator of the flexibility of the flexible PCBA structure (5802).

[0189] In some embodiments, the flexible PCBA structure (5802) may have more than one bent connection (5806) connected to the same contact pad (5804). In some embodiments, at least two bent connections (5806) may have the same flex factor.

[0190] In some embodiments, the flex factor of the flexible PCBA structure (5802) may be less than 0.015 or about 0.005.

[0191] In some embodiments, the contact pad (5804) may have a plurality of deadlock states (not shown) on it.

[0192] In some embodiments, the PCBA (e.g., FR4) may include alternating substrate layers and copper layers.

[0193] In some embodiments, the flexible PCBA structure (5802) allows for an electrical connection between the PCBA structure and other electrical contacts off the PCBA without requiring additional components (e.g., pin connectors, wire connectors, flex circuits, or additional processes such as soldering or welding), thereby saving costs. In some embodiments, the electrical connection can be made by laminating and aligning the PCBA with the flexible PCBA structure (5802) in another structure having other electrical contacts. In some embodiments, alignment of the PCBA can be performed by allowing positioning pins (2326) in the PCBA to pass through positioning holes. Since the flexible PCBA structure (5802) causes the contact pad (5804) to deviate from the plane and change orientation, the electrical connection can be made by pushing the contact pad (5804) against other electrical contacts. Alternatively, since the contact pad (5804) may include a stalemate on the back to provide necessary support, the electrical connection can be made by pushing another component onto the top of the contact pad (5804). The electrical connection can be secured in place by conventional means such as snap-fit, soldering, ultrasonic welding, electric welding, laser welding, and ultrasonic wire joining. The deflection of the contact pad (5804) can provide generous allowance to the tolerance stack, making the electrical connection secure and strong.

[0194] In some embodiments, the bent connection (5806) may be partially cut out for more deflection of the contact pad (5804). Fig. 59is a cross-sectional view of a bent connection (5806) of a flexible PCBA illustrated in FIG. 58 according to a disclosed embodiment, illustrating a partial cut-out. In this exemplary embodiment, the cut-out (5902) is located only in the substrate layer (5904). The copper layer (5906) can be kept intact. In some embodiments, the direction of the cut-out is perpendicular to the immediate operating direction of the bent connection, that is, the cut-out (5902) always cuts across the narrow width of the bent connection. The cut-out (5902) can further increase the flexibility of the flexible PCBA structure, allowing the contact pad (5804) to change direction more easily. That is, the cut-out (5902) can have the same effect as increasing the flex factor.

[0195] As discussed above, the electric engine and associated control components of a VTOL aircraft can generate heat during operation. For example, these components may include an inverter assembly, an electric motor assembly, and a gearbox assembly. The engine may accumulate heat generated from mechanical friction between parts and resistive heating within the motor-gearbox assembly. The accumulated heat may be transported to a heat exchanger by lubricating oil circulating through one or more parts of the engine. The heat must be dissipated to prevent degradation and damage to the motor, control components, and other elements of the VTOL aircraft. This heat may be managed by cooling the engine, including direct or indirect cooling. In some embodiments, cooling may be aided by a heat exchanger. The heat exchanger may be configured to receive a circulating heat exchange medium from the electric engine. For example, the heat exchange medium may include oil, and the oil may be used to lubricate and cool the components of the electric engine. The heat exchanger may interface with one or more fluids to cool a higher temperature fluid. The heat exchanger can be advantageously positioned next to the electric engine to minimize the volume (and weight) of the material required to achieve cooling and lubrication functions. In some embodiments, the heat exchanger can be fluidly, thermally, and mechanically coupled to the inverter assembly so that it shares a common connection with the inverter assembly, thereby reducing the need for components such as cables, wires, tubes, and hoses, which may add weight and require more space in the electric engine. Heat from the inverter assembly, electric motor assembly, or gearbox assembly can be transferred to a cooling fluid such as oil. The oil can absorb this heat, and the oil can then be directed to an oil tank.

[0196] As described in this specification, the electric propulsion system may include a heat exchanger. Figs. 25a-25cThis is an exemplary front view and illustration of a heat exchanger of a VTOL aircraft according to the disclosed embodiment. The heat exchanger (2504A) may be mechanically coupled to a heat plate (2502A) of an inverter assembly as described herein and illustrated in the exemplary illustration (2500A). The heat plate (2502A) may include a fin array (2506A). The fin array (2506A) may provide a heat sink to draw heat from components of the inverter assembly. As described herein, the heat exchanger (2504A) may be positioned to receive airflow from a propeller. The propeller (not shown) may direct airflow (2508A) toward the heat exchanger (2504A) and outgoing air (2510A) may exit from the heat exchanger. An airflow (2508A), which may be colder air, may be directed toward a heat exchanger (2504A), such as downwash from a propeller blade (not shown). Outgoing air (2510A), which may be warmer air, may exit the heat exchanger (2504A) without entering other components of the electric propulsion system. In some embodiments, the heat exchanger (2504A) may include cooling fins.

[0197] Figs. 25b-25cEach illustrates an example drawing of a cooling fin (2500B, 2500C) in a heat exchanger. Oil or other lubricating oil or coolant capable of absorbing heat from an electric motor assembly, gearbox assembly, or inverter assembly may be circulated through the fins of the heat exchanger (2504A). The heat exchanger (2504A) may include tubes (2504B) and fins (2502B). The tubes (2504B) may transport oil, and the fins (2502B) may be thermally coupled to the tubes (2504B). Consequently, the oil moving through the tubes (2504B) may transfer heat to another fluid heat exchange medium. The fins (2502B) may be configured to maximize the surface area of ​​the heat exchanger (2504A) to increase surface contact between the tubes (2504B) and the fluid. The increased surface area may increase the rate of heat transfer. The fluid may include air. For example, airflow (2508A) enters a heat exchanger (2504A), makes thermal contact with fins (2502C), and can receive heat from oil moving through tubes (2504C). The air can then exit the heat exchanger (2504A) as outgoing air (2510A). The heat exchanger (2504A) can transfer heat through convection.

[0198] Fig. 26[Image] is a diagram of a heat exchanger for a VTOL aircraft according to a disclosed embodiment. The heat exchanger (2600) may include a length (2602), a height (2604), and a depth (2606). As described herein, the heat exchanger (2600) may include tubes and fins to facilitate heat transfer between fluids. The heat exchanger (2600) may include a plurality of cooling paths. Section (2608) illustrates examples of different cooling paths. A lubricating oil or coolant, such as oil, may travel in the tube (2610). The tube (2610) may be thermally coupled to the fins (2612) as described herein. The tube (2610) may include a hollow tube for the fluid. The fins (2612) may increase the surface area of ​​contact between the air and the tube (2610), thereby increasing the rate of heat transfer from the oil to the air in the tube (2610) as described herein. In some embodiments, the heat exchanger (2600) may include multiple layers of fins (2612) stacked between tubes (2610) and thermally coupled thereto. Consequently, oil entering the heat exchanger (2600) may flow into other tubes (2610) to create multiple cooling paths, and heat may be transferred from the oil to the air.

[0199] As described herein, embodiments of an electric engine may include the step of circulating lubricating oil or coolant throughout the engine. A heat exchanger may cool the lubricating oil or coolant directed toward engine components such as a motor, gearbox, or inverter. In some embodiments, heat from an inverter assembly may be conducted directly to a coolant or lubricating oil, such as oil.

[0200] Figs. 27a-27bis a front view illustration of a separator plate of a VTOL aircraft according to a disclosed embodiment. In some embodiments, the separator plate may be composed of an end bell plate and a heating plate. The separator plate may include one or more plates interlocked and arranged between the motor-gearbox housing and the inverter assembly housing. Additionally, the separator plate may assist in the distribution of lubricating oil or coolant throughout the engine. In some embodiments, the separator plate may include channels, tubes, ports, cavities, or other features for carrying liquid. The end bell plate (2700) Fig. 21It may include elements and discussions similar to the end bell plate. In some embodiments, the end bell plate (2700A) may be coupled to the heat plate (2700B). In some embodiments, the end bell plate (2700A) may be adjacent to a gasket plate that may be adjacent to the heat plate (2700B). The inverter assembly may include the heat plate (2700B). The heat plate (2700B) may be mechanically, thermally, and fluidly coupled to the heat exchanger (2710B). In some embodiments, the end bell plate (2700A) and the heat plate (2700B) may be positioned over the heat exchanger. The outer perimeter of the heat plate (2700B) may be connected to the heat exchanger (2710B). The end bell plate (2700A) and the heat plate (2700B) may include channels to assist in the distribution of lubricating oil or cooling water. Here, the channel may also refer to any other conduit configured to distribute oil or other coolant or lubricant in a groove, hole, or planar direction. In some embodiments, the lubricant or coolant may be a liquid such as oil as described herein. The heating plate may be thermally and fluidly coupled to the heat exchanger by the liquid such as oil. In some embodiments, the distribution of the lubricant or coolant may be driven by a pump. The heating plate (2700B) may include any other conduit to assist the pump gear in the step of transporting oil or other liquid from a groove, hole, liquid passage, or oil container. In some embodiments, oil may be transported from the oil container at the end bell plate (2700A) through the passage rotor (2704A, 2704B) and the pump rotor (2706A) to the inlet channel (2708A). The oil in the inlet channel (2708A) may be hot or warm oil moving in the passage (2716A). Oil in the inlet channel (2708A) moves from the heat plate (2700B) to the heat exchanger inlet (2706B) and can enter any liquid flow path of the tube or heat exchanger (2710B).As described in this specification, oil circulating through the liquid flow path can be cooled in the heat exchanger (2710B), and the cooled oil can move from the heat plate (2700B) to the heat exchanger outlet (2708B). In some embodiments, oil transported between the heat plate (2700B) and the end bell plate (2700A) can move through the gasket plate. The cooled oil at the heat exchanger outlet (2708B) can then move along the flow path (2718A) to the outlet channel (2710A) and then to the annulus (2712A) and channel (2714A) of the end bell plate (2700A) and the annulus (2712B) of the heat plate (2700B). In some embodiments, oil from the annulus (2712B) may flow to the fin array (2714B) of the heating plate (2700B) to provide cooling and heat transfer. Oil from the fin array (2714B) may then return to the oil tank through a port. Some embodiments may include an annulus (2712A) substantially aligned along an axis shared with the main shaft or the gearbox assembly or the electric motor assembly. In some embodiments, as described herein, oil or liquid may move from the annulus (2712A) to the gearbox assembly or the electric motor assembly through a port hole. In some embodiments, the channel (2714A) may be fluidically connected to an additional liquid passage within the motor-gearbox housing that may serve to circulate oil or liquid to additional parts of the electric engine, such as components located near the front bearing or propeller assembly. In some embodiments, the end bell plate may include a seal of the electric engine. The end bell assembly may include a face seal between the heat exchanger and the inverter assembly to prevent oil leakage.

[0201] In some embodiments, lubricating oil or coolant may be used to cool the inverter assembly using a heat plate (2702B). Some embodiments may include hot oil or other liquid entering an inlet channel (2708A) that can be aligned with a heat exchanger inlet (2706B) to enter a heat exchanger (2710B). Cooled oil or other liquid exiting from an outlet channel (2710A) aligned with a heat exchanger outlet (2708B), and part or all of the cooled oil or liquid, may follow a liquid flow path to an annulus (2712B) of the heat plate. The oil or other liquid in the annulus (2712B) may be distributed to a heat sink located on the heat plate (2702B), such as a fin array (2714B), and the fin array (2714B) may be aligned with a power module located within the inverter assembly. Fig. 24Cooling may be provided to power modules such as those referenced in [the reference]. It should be understood that the inverter assembly may have components that may not perform well or be inefficient when exposed to oil or other liquids. Therefore, the heat plate may include a heat sink to remove heat from the inverter assembly and may circulate oil or liquid inside the heat plate and outside the inverter assembly housing to transfer heat from the heat sink to the oil or liquid to be cooled by a heat exchanger. The heat plate (2702B) may include a port hole (2716B) so that oil or liquid can pass through the port hole and enter the end bell assembly. In some embodiments, the port hole (2716B) may allow the oil to return to the oil tank. In some embodiments, the port hole (2716B) may be aligned with a port hole (2720A) present in the plate (2702A) of the end bell plate (2700A). In some embodiments, oil from the port hole (2718B) may enter the end bell assembly to circulate to an oil tank located in the motor-gearbox housing. In some embodiments, the oil may return to the oil tank along the direction of gravity, and this oil may be warm or hot. The step of cooling with oil may provide various benefits, including an improvement in the overall performance of the inverter assembly. For example, Fig. 24 As referenced, using fluid to cool the power module can improve the performance of the inverter assembly. Additionally, liquid convection can improve the durability of the inverter assembly compared to other cooling methods that involve additional components, such as air convection methods that require the addition of air cooling fins.

[0202] The disclosed embodiments of the electric propulsion system may include one or more components for distributing lubricating oil or coolant as described herein. In some embodiments, the lubricating oil or coolant, such as oil, is distributed from the oil tank (1212A) to the heat exchanger (1226A), and then to the inverter assembly, gearbox assembly, and motor assembly ( Fig. 12a It can be circulated as shown in ). Fig. 21aAs illustrated in the figure, the end bell assembly can assist in the distribution and circulation of oil. As described herein, oil moving from the heat exchanger in channel (2108A) can be distributed to an annulus (2110A) and a port (2116A) located in the annulus (2110A). As described herein, a main shaft that can be substantially aligned with the annulus (2110A) of the end bell assembly can extend from the end bell assembly through a gearbox assembly and an electric motor assembly. In some embodiments, a portion of the oil in the end bell assembly can be shared between the annulus (2110A), port (2116A), port (2122A), and various other ports and channels. Centrifugal force, centripetal force, or pressure can drive oil from an annulus (2110A), port (2116A), or groove in the bearing (2110B) along the main shaft toward the gearbox assembly and electric motor assembly. For example, pressure in the end bell assembly (2100B) can drive oil into the groove or port hole (2112B) in the bearing (2110B). Then, centrifugal force can drive oil along the main shaft from the motor assembly to the windings of the stator. For example, rotation of the main shaft can exert a centrifugal force that drives the oil to move along the main shaft. In some embodiments, oil can be transferred from the end bell assembly to the gearbox assembly and motor assembly through a hole, pipe, channel, tube, or port. For example, oil can flow in an annular region between the sun gear and the shaft. In some embodiments, the port can transfer oil from the end bell assembly to a channel or similar structure present within the motor assembly housing for the purpose of delivering oil to additional parts of the gearbox assembly or motor assembly.Some embodiments may include a propeller assembly mechanically coupled to a shaft flange or stator winding within a motor assembly, a channel configured to deliver oil to a bearing, or a similar structure.

[0203] As described herein, the amount of oil used in an electric propulsion system can be minimized by using a fluid, such as oil, to provide both lubrication and cooling. Additionally, as described herein, oil can be used to lubricate various bearings, such as rolling bearings or hydrodynamic bearings. Minimizing the amount of oil used in an electric propulsion system can reduce the mass and drag profile of the electric propulsion system. Furthermore, minimizing the amount of oil required for the operation of the electric propulsion system can ensure that the total amount of oil in the electric propulsion system is maintained below a critical amount. For example, as described herein, the electric propulsion system can reduce the amount of oil required for operation by using a heat exchanger. The warm or hot oil used for lubrication and cooling may remain in an oil tank, and by using a heat exchanger to cool this oil, the electric propulsion system may reuse the oil, thereby eliminating the need for additional oil. Additionally, as described herein, the use of a common fluid for both cooling and lubrication can reduce the mass of the components compared to other methods of cooling and lubrication using various fluids. Such configurations using various liquids may require additional mass and size of the electric propulsion system, such as additional heat exchangers, additional fluid distribution channels or tubes, and additional surface area to receive cooling air from the propeller assembly.

[0204] In some embodiments, ventilation from the airflow may provide cooling to the lubricating oil within the heat exchanger. It should be understood that while using oil to cool the electric engine rather than other coolants will add additional oil to the system, the oil will eliminate the conventional components that could be used to cool the electric engine. For example, if the electric engine is cooled by another liquid such as glycol, the engine may include separate heat exchangers for both the lubricating oil fluid and the coolant fluid. Thus, in embodiments where a single fluid such as oil is used for both lubrication and cooling, although an increase in oil exists, only one heat exchanger may be required; therefore, the mass of the overall system is reduced and a more attractive drag profile may exist because fewer heat exchangers are used and potentially other components are not required. Furthermore, using a single material for the lubrication and cooling of the engine can increase efficiency due to the reduction in mass and the benefit of cooling the engine with the material instead of relying on air cooling, which may be problematic to move throughout the engine.

[0205] Some embodiments of the inverter may include an inverter having a cooling path that moves around the outer edge of the inverter but within the inverter housing, rather than utilizing a heat exchanger. For example, the cooling path may move around any printed circuit board assembly, power module, or any inverter component present in the inverter.

[0206] As disclosed in this specification, an embodiment of an electric engine may include an inverter assembly. In some embodiments, the inverter assembly may include a heating plate. Fig. 28[Image] is a diagram of a heating plate of a VTOL aircraft according to a disclosed embodiment. The heating plate (2802) may assist in heat transfer to an inverter assembly, including the step of distributing coolant to the inverter assembly. In some embodiments, the heating plate (2802) may be adjacent to a component of the inverter assembly, such as an inverter housing or a printed circuit board. The heating plate (2802) may be thermally coupled to the inverter assembly. In some embodiments, the heating plate (2802) may be adjacent to an end bell assembly. In some embodiments, the heating plate (2802) may be adjacent to a gasket that may be adjacent to the end bell assembly. The gasket may be a metal carrier gasket. In some embodiments, the heating plate (2802) may be adjacent to a heat exchanger (2810). For example, the heating plate (2802) may be mounted on the heat exchanger (2810), and the coolant may travel through various paths in the heat exchanger (2810). For example, oil may be a cooling water that travels through various paths in a heat exchanger (2810). A pump rotor (2804) may drive oil through a cooling path in the heat exchanger (2810), which is also referred to herein as a liquid path. In some embodiments, oil or other liquid from an oil tank may be drawn through the pump rotor (2804) to a heat exchanger inlet (2806). In some embodiments, the heat exchanger (2810) may receive oil or other liquid from the heat exchanger inlet (2806) and cool the oil or other liquid, and the cooled oil or other liquid may exit the heat exchanger at a heat exchanger outlet (2808). The cooled oil from the heat exchanger (2810) may be driven by the pump (2804) to different channels on the heat plate. For example, the oil may be transported to a distribution channel (2812). In some embodiments, the heating plate (2802) may include a heat sink to help transfer heat to the inverter assembly. For example, the heating plate (2802) may include a fin array (2818).The fin array (2818) may include cooling fins extending from the base and may increase the surface area to improve heat transfer. The fin array (2818) may be located within a cavity in the heat plate (2802). The fin array (2818) may be a heat sink and may be composed of a material with high thermal conductivity. In some embodiments, the fins may be rectangular or circular in shape and may be composed of aluminum. The fin array (2818) may draw heat from a thermally and mechanically coupled inverter assembly to cool components including a switching device and a MOSFET. The fin array (2818) may be exposed to a flowing fluid. For example, cooled oil from a distribution channel (2812) may enter the fin array (2818) through channel (2814) and provide cooling and heat transfer to the fin array (2818). The oil from the fin array (2818) may then flow to a collection channel (2816). In another embodiment, oil can be transferred directly from the distribution channel (2812) to the collection channel (2816).

[0207] Fig. 29[Illustration] is an illustration of an electric propulsion system for a VTOL aircraft according to the disclosed embodiments. In some embodiments, the heating plate (2900) may be thermally coupled to the motor assembly housing (2902). The heating plate (2900) may also be fluidly coupled to the motor assembly housing (2902) by one or more cooling or lubricating channels. As described herein, the heating plate (2900) may assist in the distribution of a cooling water or lubricating oil, such as oil. For example, oil in the heating plate (2900) may enter the heat exchanger (2914) through the heat exchanger inlet (2912) and exit the heat exchanger (2914) through the heat exchanger outlet (2910). The heating plate (2900) may include a pump rotor (2908), a distribution channel (2916), a fin array (2922), and a collection channel (2920). Cooled oil from the heat exchanger (2914) enters the distribution channel (2916), flows through the fin array (2922) via the direction (2928), and can enter the collection channel (2920) via the channel (2918). As described herein, the fin array (2922) may be a heat sink and may assist in the step of transferring heat from the inverter assembly to the cooled oil (2928). In some embodiments, oil from the heat plate (2900) may be transferred to the motor assembly housing (2902). For example, the oil passage (2930) may be an example passage from the heat plate (2900) to the motor assembly housing (2902). The oil passage (2932) may be an example passage for oil from the motor assembly housing (2902) to various components. The oil (2930) may also move to a second oil passage (2934). Oil from various Euros may be moved to other components within the gearbox assembly, electric motor assembly, or motor assembly housing (2902) to provide cooling or lubrication as described in this specification. Oil distributed throughout the motor assembly housing (2902) may be accumulated in the oil container (2904).Oil may flow through the oil tank along the liquid path (2924), exit the oil tank (2904), and then flow back to the heat plate (2900) via the return path (2926). The motor assembly (2902) may be mechanically coupled to the shaft flange assembly (2906) as described herein. In some embodiments, the location of the heat plate (2900) and the heat exchanger (2914) may provide advantages to the electric propulsion system. For example, a heat plate (2900) adjacent to and liquid coupled to the heat exchanger (2914) may not require an external connection. As discussed herein, oil may move from the heat exchanger (2914) to the heat plate (2900) and be distributed to components of the electric propulsion system, such as an inverter assembly, a gearbox assembly, and a motor assembly, which may be packaged together. This configuration, including a heat plate that integrates multiple components together, does not require external connections and can reduce risks such as leakage and disconnection of these external connections.

[0208] Figs. 30a-30b [Illustration] is an illustration of an exemplary electric propulsion system for a VTOL aircraft according to the disclosed embodiments. As described herein, the electric propulsion system (3000A) may include a heat exchanger (3008A) mechanically, thermally, and fluidly coupled to a heat plate (3006A). The heat plate (3006A) may be mechanically coupled to a motor housing (3002A) comprising a liquid oil container (3004A). The electric propulsion system (3000A) may include a shaft flange assembly (3010A). In some embodiments, the electric propulsion system (3000A) may include a heat plate (3006A) and a motor housing (3002A) substantially aligned along an axis (3012A). Fig. 30b... shows an additional drawing of an electric propulsion system (3000B). A heat exchanger (3008B) may be mechanically coupled to a heat plate (3006B). The heat plate (3006B) may be mechanically coupled to a motor housing (3002B) which may include a liquid oil container (3004B). In some embodiments, the electric propulsion system (3000B) may include a heat plate (3006B) and a motor housing (3002B) that are substantially aligned along an axis (3012B).

[0209] Figs. 31a-31b is a cross-sectional view of an electric propulsion system of a VTOL aircraft according to a disclosed embodiment. Fig. 31aThis illustrates an exemplary embodiment of a tilter electric propulsion system. As disclosed herein, a tilter may refer to an electric propulsion system for tilting. The tilter (3100A) may include an inverter assembly (3104A), a gearbox assembly (3106A), and an electric motor assembly (3102A). As described herein, a heat exchanger (3118A) may be thermally, fluidly, and mechanically coupled to the inverter assembly (3104A). An inverter housing (3116A) may surround the inverter assembly (3104A). A gearbox assembly (3106A) may be adjacent to the inverter assembly (3104A) and the electric motor assembly (3102A). A motor-gearbox assembly housing (3110A) may surround the electric motor assembly (3102A) and the gearbox assembly (3106A). The oil tank (3112A) may include a fluid inlet (3114A) to transfer oil or other liquid to the heat exchanger (3118A). In some embodiments, the oil tank (3112A) may be a reservoir for holding oil. The oil tank (3112A) may be adjacent to the motor housing (3110A). In some embodiments, the main shaft (3108A) extends from the end bell assembly sealing the motor-gearbox assembly housing (3110A) through the gearbox assembly (3106A) and the electric motor assembly (3102A) to the shaft flange assembly (3120A). As described herein, the gearbox assembly (3106A) and the electric motor assembly (3102A) may be substantially aligned along the main shaft (3108A). Additionally, the inverter assembly (3104A) may be substantially aligned along an axis that shares the axis of the main shaft (3108A).

[0210] As described above, the tilter may have a variable pitch mechanism that functions to change the pitch of the propeller blades of a VTOL aircraft. In some embodiments, the variable pitch mechanism may be mounted at the rear of the electric engine assembly, such as at the rear of the inverter assembly. Additionally, the variable pitch mechanism may interact with the main shaft to change the pitch of the propeller blades as described herein. In these embodiments, the inverter assembly (3104A), the inverter assembly housing (3116A), and the separator may have a housing that allows the variable pitch mechanism to interface with the main shaft or propeller blades through the packaging and the configuration as discussed herein. As discussed in its entirety, the lifter electric propulsion system may not change the direction of the thrust or pitch of the blades. Accordingly, in some embodiments, the separator may not have a passage such as that present in the tilter electric propulsion system. In addition, while the inverter assembly and inverter assembly housing of the lifter electric propulsion system may not have such passages, it is recognized that from the perspective of safety testing and manufacturability, it may be advantageous to have the inverter assembly and inverter assembly housing of the lifter electric propulsion system have packaging similar to that of the tilter electric propulsion system, including passages.

[0211] Fig. 31bThis illustrates an exemplary embodiment of a lifter electric propulsion system. As disclosed herein, a lifter may refer to an electric propulsion system for lifting. The lifter (3100B) may include an inverter assembly (3104B), a gearbox assembly (3106B), and an electric motor assembly (310BA). As described herein, a heat exchanger (3118B) may be thermally, fluidly, and mechanically coupled to the inverter assembly (3104B). An inverter housing (3116B) may surround the inverter assembly (3104A). A gearbox assembly (3106B) may be adjacent to the inverter assembly (3104B) and the electric motor assembly (3102B). A motor-gearbox housing (3110B) may surround the electric motor assembly (3102B). In some embodiments, the main shaft (3108B) extends from an end bell assembly sealing the motor-gearbox housing (3110B) through a gearbox assembly (3106B) to an electric motor assembly (3102B). As described herein, the gearbox assembly (3106B) and the electric motor assembly (3102B) may be substantially aligned along the main shaft (3108B). Additionally, the inverter assembly (3104B) may be substantially aligned along an axis that shares the axis of the main shaft (3108B).

[0212] As discussed in this specification, it is noted that having similar components between the tilter and the lifter electric propulsion system may be advantageous with respect to the manufacturability of the overall aircraft. Additionally, using similar components between the tilter and the lifter electric propulsion system may be advantageous in terms of diagnosing problems and ensuring that safety requirements and protocols are met. However, in some embodiments, the lifter and the tilter may have components that do not exist within the other. For example, the lifter electric propulsion system (3100B) may include a locking nut (3112B) located between the main shaft (3108B) and the shaft flange assembly (3120B), which is larger than the locking nut present within the tilter electric propulsion system (3100A). The locking nut (3122B) may function to ensure that the mechanical connection between the main shaft (3108B) and the shaft flange assembly (3120B) is not damaged or deteriorated due to various vibration loads experienced throughout the flight. For example, as discussed in this specification, some flight phases do not require the lifter electric propulsion system to be activated, and in such cases, the blade may need to be stored in a specific manner. However, if the lifter blade is not properly stored, drag may be experienced on the blade, and the mechanical connection between the main shaft (3108B) and the shaft flange assembly (3122B) may be subjected to tension. Additionally, in some embodiments, the locking nut (3112B) of the lifter electric propulsion system (3100B) may withstand operating loads. In some embodiments, the lifter electric propulsion system may also include a larger propeller flange (3126A) compared to the shaft flange of the tilter for reasons similar to the presence of the locking nut (3122B). Additionally, the lifter electric propulsion system may also include a bearing (3124A) to assist in the rotation of the propeller flange (3126A). As described in this specification, the electric propulsion system can achieve various directional angles during operation.Therefore, fluids in an electric propulsion system, including coolants or lubricants, can move due to gravity. For example, lubricants or coolants, such as oil, can move within the electric propulsion system during operation. Oil may be present in a tank and may move within the tank and the electric propulsion system. Regardless of orientation, some embodiments may require a small amount of oil or other liquid to function as a coolant or lubricant throughout all flight phases. Thus, the cooling system can be designed to allow the circulation of oil regardless of the aircraft's orientation.

[0213] Figs. 32a-32d is a cross-sectional view of an electric propulsion system of a VTOL aircraft according to a disclosed embodiment. Figs. 32a-32d refers to similar elements of the electric propulsion system (3200A, 3200B, 3200C, and 3200D) having similar numbers. Therefore, similar design considerations and configurations can be considered throughout the embodiments.

[0214] Fig. 32aThis illustrates an exemplary embodiment of an electric propulsion system in a vertical direction. For example, the vertical direction may be achieved during flight operations, including but not limited to takeoff, landing, or hovering. The electric propulsion system (3200A) may include a motor-gearbox assembly housing (3202A), an inverter assembly housing (3204A), a main shaft (3206A), a shaft flange assembly (3120), a heat exchanger (3208A), and an oil tank (3210A). A lubricating oil or coolant, such as oil (3212A), may be located in the oil tank (3210A). In the exemplary direction (3200A), the oil may also be present in the oil tank (3210A) and in the volume (3218A) at the oil level (3216A). The oil (3212A) may enter through the pump inlet (3214A) and move to the heat exchanger (3208A). Afterward, as described in this specification, the oil (3212A) can be cooled in a heat exchanger (3208A) and distributed throughout the electric propulsion system. In some embodiments, the oil can be distributed along the main shaft (3206A) by centrifugal force.

[0215] Fig. 32b This illustrates an exemplary embodiment of an electric propulsion system (3200B) in a first angled direction, such as a hovering direction at an angle (3222B). For example, the electric propulsion system (3200B) may be oriented along the central axis (3224B) at an angle (3222B) from the vertical axis (3226B). Fig. 32b As illustrated in the figure, the electric propulsion system (3200B) is in an angled direction, but the pump inlet (3214B) maintains contact with the oil (3212B) below the oil level (3216B) so that the oil can continue to circulate through the liquid path as described in this specification.

[0216] Fig. 32cillustrates an exemplary embodiment of an electric propulsion system (3200C) in a horizontal direction. For example, the electric propulsion system (3200C) may be in a horizontal direction during forward flight or cruising configuration. Fig. 32c As illustrated in the figure, during the horizontal direction, the pump inlet (3214C) maintains contact with the oil (3212C) below the oil level (3216C) so that the oil can continue to circulate through the liquid channel as described in this specification. Additionally, the volume (3218C) may not contain oil during the horizontal configuration due to gravity.

[0217] Fig. 32d illustrates an exemplary embodiment of an electric propulsion system in a second angled direction, such as diving at an angle (3222D). Fig. 32d As illustrated in [Image], during the diving direction, the pump inlet (3214D) maintains contact with the oil (3212D) below the oil level (3216D) so that the oil can continue to circulate through the liquid path as described herein. Additionally, the volume (3218D) may not contain oil during the horizontal configuration due to gravity. In some embodiments, oil or other combustible liquid may be used as a lubricant throughout the electric engine and may also be used as a coolant fluid to assist in managing the heat generated by the engine during operation. As disclosed herein, electric engines may have different primary functions and therefore may not contain the same amount of lubricant and coolant. For example, lifting and landing engines may require less than 1 quart of oil, while engines operating at all stages of flight may require more than 1 quart of oil. As mentioned herein, it should be understood that exemplary embodiments are exemplary and do not indicate a range of amounts of lubricant and coolant that may be used in the electric engine.

[0218] It should be understood that using oil to cool the electric engine, rather than other coolants, will add additional oil to the system, but the oil will eliminate the conventional components that could be used to cool the electric engine. For example, if the electric engine is cooled by another liquid such as glycol, the engine may include separate heat exchangers for both the lubricating oil fluid and the coolant fluid. In some embodiments, the electric engine may be cooled using various liquids. Some embodiments may include an electric propulsion system comprising multiple heat exchangers that cool individual liquids flowing in individual liquid passages. In some embodiments, multiple cooling and / or lubricating liquids, such as glycol and oil, may have individual liquid passages circulating through a common heat exchanger, also known as a dual heat exchanger. In such configurations, the number of heat exchangers may be fewer than the number of types of liquid passages based on the liquid type, and the overall propulsion system may save mass by not having multiple or more heat exchangers.

[0219] However, in embodiments utilizing a single fluid, such as oil, for both lubrication and cooling, although an increase in oil is present, only one heat exchanger may be required; thus, the overall system mass is reduced and a more attractive drag profile may exist because fewer heat exchangers are used and potentially other components are not needed. Additionally, using a single material for engine lubrication and cooling can increase efficiency due to the reduction in mass and the benefit of cooling the engine with the material instead of relying on air cooling, which can be problematic to move throughout the engine.

[0220] As described herein regarding the use of oil or other flammable liquids in electric propulsion systems, federal laws and regulations may require safety components, such as fire barriers adjacent to engines using more than a critical amount of oil or other flammable liquids. Such federal laws and regulations may be enforced by government agencies, such as the U.S. Federal Aviation Administration.

[0221] It should be noted that, as described herein, some embodiments of electric propulsion systems may not include fire barriers. As used herein, fire barriers may include engine components or aircraft components designed, constructed, or installed for the primary purpose of preventing harmful amounts of air, fluid, or flame from passing around or through the fire barrier and / or protecting it from corrosion. In some embodiments, fire barriers may be required for each electric propulsion system present in the aircraft. Thus, as described herein, if the aircraft has, for example, 12 electric propulsion systems, 12 fire barriers may need to be installed on the aircraft. In some embodiments, fire barriers may need to be present on each wing surrounding the airframe or on any other configuration based on federal laws, regulations, or other safety requirements. Therefore, the presence of fire barriers may add additional mass to the aircraft, thereby reducing the efficiency of the electric propulsion system and limiting the amount of payload present in the aircraft, including passengers. This is particularly relevant to VTOL aircraft designs, where a single aircraft can have, for example, 12 electric propulsion systems, and thus can experience a 12-fold increase in any mass due to a single fire barrier.

[0222] As described herein, some embodiments do not include fire barriers, whereas additional forms of all embodiments described and considered herein may include fire barriers. Additionally, as described herein, each embodiment may have fire barriers of various types and locations.

[0223] Figs. 33a-33c is a schematic diagram illustrating an exemplary electric propulsion system of a VTOL aircraft including a fire barrier according to a disclosed embodiment. . Fig. 33a This shows an exemplary electric propulsion system (3300A) including a fire barrier (3308A) according to the present disclosure. The fire barrier (3308A) may be positioned between the boom (3304A) and the electric engine assembly (3302A) mechanically coupled to the propeller assembly (3306A) for the primary purpose of preventing any fire or combustion that may occur in the electric engine assembly (3302A) from spreading to other areas of the aircraft.

[0224] Fig. 33b This illustrates an exemplary VTOL aircraft (3300B) according to the present disclosure. The VTOL aircraft (3300B) may include a fire barrier (3306B) mounted on or connected to a wing (3304B) connected to a fuselage (3302B). Fig. 33b As illustrated in the figure, a fire barrier (3306B) may be positioned between the wing (3304B) of the VTOL aircraft (3300B) and the electric propulsion system, which includes an electric engine (3308B) and a propeller assembly (3310B), for the primary purpose of stopping any fire or combustion. In some embodiments, the fire barrier (3306B) may be positioned between the wing (3304B) and the boom housing the electric propulsion system.

[0225] Fig. 33cThis illustrates an exemplary electric propulsion system (3300C) according to the present disclosure. In some embodiments, the electric propulsion system (3300C) may include an electric motor assembly (3302C) comprising a gearbox assembly and an inverter assembly (3304C) fluidly coupled to a heat exchanger (3306C). In some embodiments, the electric motor assembly (3302C) may be adjacent to the inverter assembly (3304C). Some embodiments may also include an electric engine assembly housing (3308C). The electric engine assembly housing (3308C) may include a fire barrier (3310C). In some embodiments, the fire barrier (3310C) may also function to accommodate the rear of the electric engine assembly and the inverter assembly as illustrated in this drawing.

[0226] In some embodiments, fire risk management in aircraft design may not be limited to the inclusion of fire barriers. Additional design considerations, such as additional components to ensure the aircraft can maintain flight in the event of a fire, may address fire risks. For example, as described herein, an aircraft boom may feature additional components present within the boom to ensure that the aircraft can still maintain a balanced flight in the event that a fire occurs and components are lost by fire, or components are separated by fire, or any other loss of functionality or components occurs.

[0227] C. Example electric propulsion system configuration

[0228] As discussed above and throughout this disclosure, exemplary electric propulsion systems may include electric motor assemblies, gearbox assemblies, and inverter assemblies across various configurations, such as representative configurations as described herein. As discussed herein, exemplary embodiments may include components of an electric propulsion system aligned along a common axis or substantially aligned along a common axis. In some embodiments, components may be aligned along a main shaft that provides mechanical axial power to rotate a shaft or propeller of a propeller assembly. Some embodiments may include components of an electric propulsion system adjacent to each other, arranged sequentially along an axis or substantially aligned along an axis. In some embodiments, the location or arrangement of one or more electric propulsion systems may provide a reduction in the mass of the system and generate a more efficient drag profile. For example, one or more components may be substantially aligned along a common axis or adjacent to each other, and additional components, such as connecting wires or additional housing volumes to accommodate the wires, may not be required. Thus, the individual mass and volume typically required to accommodate such connecting wires may not be required in the disclosed electric propulsion system.

[0229] In some embodiments, the electric propulsion system may also include a cooling system configured to target multiple heat-generating parts of the electric propulsion system. Some embodiments may include a portion of the electric propulsion system that is air-cooled by airflow generated from the propeller assembly or by airflow encountered during various flight phases. Some embodiments may include a portion of the electric propulsion system that is cooled using one or more liquid passages throughout the electric propulsion system. Such embodiments may include liquid passages circulating through a heat exchanger exposed to airflow so that any heat contained in the liquid passages can be transferred to the air flowing through the heat exchanger. As described herein, it should be understood that the components of the electric propulsion system may all be cooled using a common cooling system, each may have its own independent cooling system, or a combination of cooling systems of various types and configurations may be used. In some embodiments, the individual cooling systems of the electric propulsion system may affect the efficiency of the components of the electric propulsion system. For example, in some embodiments, liquid cooling may cause the inverter assembly to operate more efficiently than an inverter assembly utilizing an air cooling system.

[0230] Figs. 34a-34d is a schematic diagram illustrating an exemplary electric propulsion system of a VTOL aircraft according to the disclosed embodiment. Accordingly, similar design considerations and configurations may be considered throughout the embodiment.

[0231] Fig. 34aThis schematically illustrates an exemplary electric propulsion system (3400A) according to the present disclosure. The electric propulsion system (3400A) may include components such as an inverter assembly (3404A), at least one power module (3410A), and an electric motor assembly (3402A) oriented along an axis extending along a shaft (3406A). An embodiment may include an electric motor assembly (3402A) that provides torque to a propeller assembly (3408A) through the shaft (3406A). In some embodiments, the shaft (3406A) may be mechanically coupled to a gearbox assembly (not shown in this exemplary embodiment) to provide gear reduction and increased torque to the propeller assembly (3408A). The housings of the components of the electric propulsion system (3400A) may share a common shape, such as a circular profile centered on the shaft (3406A), a rectangular profile oriented along the shaft (3406A), or a mixture of profiles. The electric propulsion system (3400A) may further include an electric motor assembly (3402A) located between the inverter assembly (3404A) and the propeller assembly (3408A) and adjacent thereto. In this embodiment, a shaft (3406A) may pass through the electric motor assembly (3402A). Some embodiments may also include a shaft (3406A) passing through the inverter assembly (3404A). In some embodiments, a power module (3410A) may be axially oriented toward the inverter assembly (3404A) so that any heat generated by the power module can escape through a path (3412A) to the environment outside the inverter assembly (3404A). Some embodiments may also include a step of oriented the power module (3410A) from the inverter assembly (3404A) so that the air generated by the propeller assembly (3408A) or the air flow encountered during flight can be used to cool the power module.

[0232] Fig. 34bThis schematically illustrates an exemplary electric propulsion system (3400B) according to the present disclosure. The electric propulsion system (3400B) may include components such as an inverter assembly (3404B), at least one power module (3410B), and an electric motor assembly (3402B) aligned along an axis extending along a main shaft (3406B). The electric propulsion system (3400B) may further include an inverter assembly (3404B) located between the electric motor assembly (3402B) and the propeller assembly (3408B). In some embodiments, the power module (3410B) may be located in part of the inverter assembly (3404B) so as to be located below the propeller assembly (3408B) and generate heat that escapes through a path (3412B) to the environment outside the inverter assembly (3404B). Some embodiments may include a power module directed away from the inverter assembly so that any airflow generated by the propeller assembly (3408B) can be used to cool the power module.

[0233] Fig. 34cThis schematically illustrates an exemplary electric propulsion system (3400C) according to the present disclosure. The electric propulsion system (3400C) may include components such as an inverter assembly (3404C), at least one power module (3410C), and an electric motor assembly (3402C) aligned along an axis extending along a shaft (3406C). The electric propulsion system (3400C) may further include an inverter assembly (3404C) located between the electric motor assembly (3402C) and the propeller assembly (3408C). In some embodiments, the power module (3410C) may be located in a portion of the inverter assembly (3404C) so as to be located on the surface of the inverter assembly (3404C) adjacent to the electric motor assembly (3402C). In some embodiments, the power module (3410C) may be located within the electric propulsion system (3400C) as shown in path (3412C), as opposed to being located in the inverter assembly (3404C) where the heat generated by the power module (3410C) cannot be cooled using air cooling from the propeller assembly (3408C) or any airflow encountered during flight. In these embodiments, liquid cooling may be used to cool the power module (3410C) as well as other components located within the inverter assembly (3404C). Additional embodiments may also include a liquid cooling system that thermally manages components of the electric motor assembly (3402) and / or components of the gearbox assembly.

[0234] Fig. 34dThis schematically illustrates an exemplary electric propulsion system (3400D) according to the present disclosure. The electric propulsion system (3400D) may include components such as an inverter assembly (3404D), at least one power module (3410D), and an electric motor assembly (3402D) oriented along an axis extending along a shaft (3406D). The electric propulsion system (4100D) may further include an electric motor assembly (3402D) located between the inverter assembly (3404D) and the propeller assembly (3408D). In some embodiments, the power module (3410D) may be located in a part of the inverter assembly (3404D) so as to be located on the surface of the inverter assembly (3404D) adjacent to the electric motor assembly (3402D). In some embodiments, the power module (3410D) may be located within the electric propulsion system (3400D) as shown in path (3412D), as opposed to the inverter assembly (3404D) where the heat generated by the power module (3410D) cannot be cooled using air cooling from the propeller assembly (3408D) or any airflow encountered during flight. In these embodiments, liquid cooling may be used to cool the power module (3410D) as well as other components located within the inverter assembly (3404D). Additional embodiments may also include a liquid cooling system that thermally manages components of the electric motor assembly (3402) and / or components of the gearbox assembly.

[0235] In some embodiments, the electric propulsion system may include a cooling system that utilizes liquid cooling. In some embodiments, the cooling system liquid may include glycol, oil, or any liquid that enables the electric propulsion system to transfer heat from a component to a liquid. Additionally, some embodiments may also include a step of cooling the electric propulsion system using a liquid used to lubricate the components of the electric propulsion system. In some embodiments, the electric propulsion system may include an oil tank, reservoir, or cavity for collecting and circulating coolant liquid throughout the electric propulsion system.

[0236] Fig. 35 is a schematic diagram illustrating an exemplary electric propulsion system of a VTOL aircraft according to a disclosed embodiment. The electric propulsion system (3500) may include components such as an electric motor assembly (3502), an inverter assembly (3504), and an oil tank (3514) aligned along a shaft (3506). Fig. 35As illustrated in the figure, the electric motor assembly (3502) may be located between the oil tank (3514) and the inverter assembly (3504). The electric motor assembly (3502) may provide torque to the propeller assembly (3508) via a main shaft (3506) that can move through the inverter assembly (3504). Additionally, the electric motor assembly (3502) may provide torque to the propeller assembly (3508) through gear reduction using a gearbox assembly (not shown in this exemplary embodiment). The inverter assembly may include a power connection channel (3518) connected to the inverter assembly (3504). The inverter assembly (3504) may include a power module (3510) located on the opposite side of the inverter assembly (3504) as a part adjacent to the electric motor assembly (3502). Additionally, some embodiments may include a power module (3510) located within an inverter assembly (3504) so ​​that any heat generated by the power module (3510) can escape through a path (3512) to an environment outside the inverter assembly. Some embodiments may include various cooling methods for the components of the electric propulsion system (3500). For example, in some embodiments, the power module (3510) may be located below the propeller assembly (3508) so that air from the propeller assembly (3508) cools the power module (3510). Additionally, an oil tank (3514) may contain a liquid for cooling or lubricating the electric motor assembly (3502), gearbox assembly, and / or inverter assembly (3504). Some embodiments may include components of the electric propulsion system (3500) having various housing profiles, such as a circular housing centered on a shaft (3506), a mixture of housing profiles, and a housing profile that allows for an aerodynamic drag profile. Some embodiments may include a component housing having cooling fins attached to the outer surface of the housing.

[0237] Fig. 35 As illustrated in the figure, the oil tank (3514) may have cooling fins (3516) in the housing of the oil tank to assist in the step of extracting heat from the liquid used to lubricate or cool the electric motor assembly (3502), gearbox assembly and / or inverter assembly (3504). Some embodiments disclosed herein may include electric propulsion system components aligned along a common axis, while some embodiments include components substantially aligned along a common axis.

[0238] In some embodiments, the electric propulsion system may include components that are not aligned along the axis or are substantially not aligned. For example, the electric propulsion system may include an electric motor assembly aligned along the shaft that provides mechanical shaft power to the propeller assembly, and an inverter assembly that supplies alternating current to the electric motor assembly located elsewhere within the aircraft. Some embodiments may accommodate an inverter assembly that is not adjacent to the electric motor assembly but is instead housed in the boom, wing, or elsewhere within the fuselage. In these embodiments, wiring may operate from the inverter assembly to the electric motor assembly to transmit alternating current from the inverter. Separating the locations of the components of the electric propulsion system may increase the mass of the aircraft due to the necessary wiring and other connection components.

[0239] Figs. 36a-36b is a schematic diagram illustrating an exemplary electric propulsion system of a VTOL aircraft according to the disclosed embodiment. Accordingly, similar design considerations and configurations may be considered throughout the embodiment.

[0240] Fig. 36aThis schematically illustrates an exemplary electric propulsion system (3600A) according to the present disclosure. The electric propulsion system (3600A) may include components such as an electric motor assembly (3602A) centered along a shaft (3606A) that provides torque to a propeller assembly (3608A). An embodiment of the electric propulsion system (3600A) may also include a rectangular inverter assembly (3604A) cantilevered behind the electric motor assembly (3602A). Additionally, some embodiments may include an inverter assembly (3604A) having cooling fins (3610A) oriented so that the cooling fins (3610A) can utilize airflow from the propeller assembly (3608A) in a step where the cooling fins (3610A) cool a power module, a MOSFET, or other components present in the inverter assembly (3604A). In some embodiments, the electric motor assembly (3602A) may be housed in a housing having various profiles, including circular, rectangular, or any other type of profile depending on the design and needs of the system. The electric motor assembly (3602A) may also be present in a motor housing having cooling fins to assist in cooling elements of the electric motor assembly (3602A), such as the stator, stator windings, or any other element of the electric motor assembly (3602A). Although not shown in this drawing, a gearbox assembly may be present between the electric motor assembly (3602B) and the propeller assembly (3608B), between the electric motor assembly (3602B) and the inverter assembly (3604B), within the housing containing the electric motor assembly (3602B), or in any other configuration where a gear reduction exists. Additionally, although not shown in this drawing, the gearbox assembly may be present within the motor housing and may utilize cooling fins to assist in thermal management.

[0241] Fig. 36b Is Fig. 36aAs disclosed in, an exemplary electric propulsion system (3600B) is schematically illustrated and a front view from the propeller assembly (3608A) is provided. The electric propulsion system (3600B) may include a circular electric motor assembly (3602B) aligned along a shaft (3606B). An embodiment of the electric propulsion system (3600B) may also include a rectangular inverter assembly (3604B) that may be located behind the electric motor assembly (3602B). The inverter assembly (3604B) may be located adjacent to the electric motor assembly (3602B) or within the boom, wing, or airframe. The inverter assembly (3604B) may have cooling fins (3608B) that extend past the outer diameter of the electric motor assembly (3602B) so that the cooling fins (3608B) are exposed to airflow from the propeller assembly (3608A) or airflow encountered during flight. Additionally, the cooling fins (3608B) may be used to extract and transfer heat generated by other components present in the power module, MOSFET, or inverter assembly (3604A). The cooling fins (3608B) may transfer heat to an environment outside the electric propulsion system. Likewise, the electric motor assembly (3602B) may also have unique cooling fins (not shown) located in the housing of the electric motor assembly to assist in the heat management of the electric motor assembly (3602B) and any gearbox assembly.

[0242] In some embodiments, the electric propulsion system may include thermal management, which is also referred to herein as a cooling system, comprising liquid cooling. As disclosed herein, some exemplary cooling systems may include the step of distributing liquid coolant to components located throughout the electric motor assembly, gearbox assembly, and inverter assembly. However, as disclosed herein, it should be understood that the cooling system may also include liquid coolant circulating around the electric motor assembly, gearbox assembly, and / or inverter assembly. For example, the cooling system may include a cavity, jacket, or distribution channel of the cooling system that circulates liquid coolant around components located within the electric propulsion system.

[0243] Fig. 37[This is a schematic diagram illustrating an exemplary electric propulsion system for a VTOL aircraft according to the disclosed embodiment. The electric propulsion system (3700) may include a motor assembly housing (3702) that accommodates an electric motor assembly adjacent to an inverter assembly housing (3708) and a shaft (3706) that travels through the motor assembly housing (3702). In some embodiments, the motor assembly housing (3702) and the inverter assembly housing (3708) may have various shapes or profiles, such as a circular housing, a rectangular housing, or any other suitable geometric direction centered along an axis that coincides with the shaft (3706). Some embodiments may include a motor assembly housing (3702) that accommodates a gearbox assembly in addition to accommodating an electric motor assembly. The embodiments may include a gearbox assembly located between the electric motor assembly and the propeller assembly outside the motor assembly housing (3702), an electric motor assembly located between the gearbox assembly and the propeller assembly outside the motor assembly housing (3702), a gearbox assembly located within the motor assembly housing (3702) but not aligned along the axis of the electric motor assembly, or any other configuration of a gearbox assembly sharing a housing with the electric motor assembly. Some embodiments may include an inverter assembly housing (3708) having an inverter assembly (3704) as described herein. Additionally, the inverter assembly housing (3708) may have cooling fins (3710) located on the outer surface of the inverter assembly housing (3708) that utilize airflow encountered during flight to assist in cooling the components of the inverter assembly (3704). Some embodiments may also include an inverter assembly (3704) that utilizes liquid cooling rather than air cooling for thermal management.These embodiments may include a cavity (3714), a jacket, or a distribution channel around the inverter assembly (3704) so ​​that the liquid can be circulated through the cavity (3714), a jacket, or a distribution channel to extract heat generated from the components of the inverter assembly (3704). Additionally, the liquid may be used to cool components within the motor assembly housing (3702). Path (3712) illustrates an exemplary liquid flow path for cooling components located within the motor assembly housing (3702) so that the liquid can move from a first end of the motor assembly housing to a second end of the motor assembly housing along the main shaft (3706) through a distribution channel. The liquid may be distributed radially from the shaft (3706) and collected through a collection chamber, an oil tank, or a similar component to be recirculated throughout the motor assembly housing (3702). In some embodiments, the electric motor assembly housing (3702) may be fluidly coupled to the inverter assembly housing (3708) so that liquid coolant can circulate throughout both assemblies through the liquid passage (3712) and cavity (3714). In some embodiments, the motor assembly housing (3702) and the inverter assembly housing (3708) may utilize air cooling, liquid cooling, or a combination of both to thermally manage the components located within each housing.

[0244] As discussed herein, an electric propulsion system may include components of various configurations, such as components aligned along an axis, adjacent to each other, substantially aligned along an axis, or connected by wires or other connection methods. Accordingly, some embodiments may include components that share a housing. For example, as discussed above, a gearbox assembly may be accommodated within a motor assembly housing. Additionally, some embodiments may include the step of accommodating other assemblies or components of these assemblies within a gearbox assembly, an inverter assembly, or a propeller assembly. Such configurations may be driven by design constraints such as weight, drag profile, lift, torque, payload, flight time, or any other design constraints related to VTOL aircraft.

[0245] Figs. 38a-38b[This is a schematic diagram illustrating an exemplary electric propulsion system and an exemplary inverter assembly of an electric propulsion system for a VTOL aircraft according to the disclosed embodiments. The electric propulsion system (3800A) may include a motor assembly housing (3802A) aligned along a main shaft (3806A). Some embodiments may include a motor assembly housing (3802A) including an electric motor assembly aligned centrally along the main shaft (3806A). Some embodiments may include a motor assembly housing (3802A) that accommodates an electric motor assembly and a gearbox assembly. Some embodiments of the electric propulsion system (3800A) may also include an inverter assembly (3804A) mounted on a circular surface of the motor assembly housing (3802A) having a low-voltage input (3808A) located on the surface of the motor assembly housing (3802A). In some embodiments, the inverter assembly (3804A) may be located within the propeller assembly as well as mounted on the motor assembly housing (3802A). For example, as described in this specification, the inverter assembly may be located within the spinner of the propeller assembly. When other components of the electric propulsion system (3800A) do not justify creating a more compact drag profile, the placement of this inverter assembly (3704A) may be advantageous. For example, the propeller assembly may have a specific size to satisfy additional design criteria, such as required torque or lift, and in this embodiment, the size of the propeller assembly may have a void space that allows the inverter assembly (3804A) to be located within the hub of the propeller assembly.

[0246] Fig. 38bThis schematically illustrates an exemplary inverter assembly (3800B) in accordance with the discussion of the inverter assembly (3804A) as well as the entire disclosure. The inverter assembly (3800B) may include at least one power module (3802B), at least one gate drive (3804B), at least one control panel (3806B), at least one DC capacitor or low inductance connector (3808B), and at least one DC current input port (3810B). Additionally, the inverter assembly (3800B) may have cooling fins (3812B) located on the outer surface of the inverter assembly housing to assist in cooling various components of the inverter assembly (3800B).

[0247] In some embodiments, the electric propulsion system may include components residing within various component housings. As discussed herein, various components of the electric propulsion system may reside within housings and may be arranged in various ways within these housings. Various embodiments of the electric propulsion system may include various configurations of components to achieve various design goals. Different embodiments may have different key design components that must be achieved at the expense of different design criteria. For example, some embodiments may include redundant systems that increase passenger safety by avoiding and / or eliminating a single point of failure, but may add additional mass to the aircraft. Additionally, some embodiments of the electric propulsion system may include various types of thermal management systems, which are also referred to herein as cooling systems. Some electric propulsion systems may include a combination of cooling systems, such as air cooling and liquid cooling systems. For example, an electric propulsion system component may have an air cooling design, such as a component mechanically coupled to cooling fins, and a liquid cooling design, such as a heat exchanger and a liquid flow path, in which the component extracts heat from a liquid and transfers it to the outside air.

[0248] Figs. 39a-39dThis is a schematic diagram illustrating an exemplary electric propulsion system for a VTOL aircraft according to the disclosed embodiment. The electric propulsion system (3900A) may include an inverter assembly (3904A), a gearbox assembly (3906A), an electric motor assembly (3902A), and a main shaft (3908A) connected to a flange shaft assembly (3912A). In some embodiments, the electric motor assembly (3902A) may be located between the gearbox assembly (3906A) and the shaft flange assembly (3912A), while both the gearbox assembly (3906A) and the electric motor assembly (3902A) are aligned along the main shaft (3908A). Additionally, the inverter assembly (3904A) may be adjacent to the motor-gearbox housing (3910A), and the inverter assembly (3904A) may have a rectangular profile. In some embodiments, the inverter assembly (3904A), electric motor assembly (3902A), and gearbox assembly (3908A) may have a common or separate cooling system. For example, the motor-gearbox housing (3910A) and / or the inverter assembly (3904A) may utilize airflow generated by the propeller assembly or facing during flight to cool the inverter assembly (3904A), gearbox assembly (3906A), and / or electric motor assembly (3902A).

[0249] Fig. 39b Is Fig. 39a A perspective view of an example electric propulsion system is shown. Fig. 39b and Fig. 39aAlthough related, the drawings may have similar numbers that do not refer to the same elements. In some embodiments, the electric propulsion system (3900B) may include an electric motor assembly (3902A) and a gearbox assembly (3906A) may be located within a motor-gearbox housing (3910B). The motor-gearbox housing (3910B) may be aligned along a main shaft (3908B) which is connected to the flange shaft assembly (3912B) and has cooling fins (3914B) oriented toward the circumference of the electric engine housing (3910B) to cool the electric motor assembly (3902A) and gearbox assembly (3906A) using airflow from a propeller assembly (not shown) connected to the flange shaft assembly (3912B) or airflow encountered during flight. Additionally, the inverter assembly (3904B) can be mechanically coupled to the rear of the motor-gearbox housing (3910B) and can also utilize airflow in the step of cooling the components of the inverter assembly (3904B).

[0250] Fig. 39c The present disclosure provides a schematic diagram of an exemplary electric propulsion system (3900C) according to an embodiment of the present disclosure. The electric propulsion system (3900C) may include an electric motor assembly (3902C) and a gearbox assembly (3906C) located within a motor-gearbox housing (3910C). In this embodiment, a propeller assembly (3912C) may be mechanically coupled to a first end of the motor-gearbox assembly (3910C). Some embodiments may include a shaft that travels to the propeller assembly (3912C) through the electric motor assembly (3902C) and / or the gearbox assembly (3906C). Fig. 39cAs illustrated in the example embodiment, an electric motor assembly (3902C) located between a gearbox assembly (3906C) and a propeller assembly (3912C) may be included. Additionally, some embodiments may include an inverter assembly (3904C) adjacent to a second end of the motor-gearbox assembly (3910C).

[0251] Fig. 39d [This] provides a schematic diagram of an exemplary electric propulsion system according to an embodiment of the present disclosure. The electric propulsion system (3900D) is Fig. 39d It may include a similar arrangement of components as illustrated in [Image]. However, the electric propulsion system (3900D) may include a gearbox assembly (3906D) located between an electric motor assembly (3902D) and a propeller assembly (3912D) connected to the first end of the motor-gearbox housing (3910D), having an inverter assembly (3904D) adjacent to the second end of the motor-gearbox housing (3910D).

[0252] Figs. 40a-40d is a diagram and cross-sectional view of an electric propulsion system of a VTOL aircraft according to a disclosed embodiment. Fig. 40aThe figure illustrates a cross-sectional view of an exemplary electric propulsion system (4000A). The electric propulsion system (4000A) may include an inverter assembly (4004A), a gearbox assembly (4006A), and an electric motor assembly (4002A) aligned along a main shaft (4020A) connected to a shaft flange assembly (4008A). The gearbox assembly (4006A) and the electric motor assembly (4002A) may be located within a motor-gearbox assembly housing (4012A), and the inverter assembly (4004A) may be located within an inverter assembly housing (4014A). Additionally, the inverter assembly housing (4014A) may be mounted on the rear of the motor-gearbox assembly housing (4012A). Additionally, a power connection channel (4018A) may be connected to a connector of the inverter assembly (4004A) located in the inverter assembly housing (4014A). Fig. 40a As illustrated in the exemplary embodiment, the power connection channel (4018A) may be connected to the inverter assembly (4004A) behind the heat exchanger (4010A). In addition to this embodiment, the heat exchanger (4010A) may be mounted in the motor-gearbox assembly housing (4012A) and may be used along a distribution channel (not shown) to assist in cooling the electric motor assembly (4002A), gearbox assembly (4006A), and / or inverter assembly (4004A) by cooling the liquid circulating throughout the electric propulsion system (4000A). In the drawings, the inverter assembly (4004A), gearbox assembly (4006A), and electric motor assembly (4002A) are shown to conform to the described stacked assembly inverter assembly, planetary gearbox, and electric motor comprising a stator and a rotor; however, it should be understood that the drawings are examples and the inverter assembly, gearbox assembly, and electric motor assembly may be of any type capable of achieving the same or similar functionality as described herein.

[0253] Fig. 40bThe electric motor assembly (4002A) and the gearbox assembly (4006A) are located within the motor-gearbox housing (4012B). Fig. 40a A perspective view of an example electric propulsion system (4000B) is shown. In some embodiments, the motor-gearbox housing (4012B) may be aligned along a main shaft (4020B) connected to a shaft flange assembly (4008B). The motor-gearbox housing (4012B) may have cooling fins (4022B) oriented around the circumference of the motor-gearbox housing (4012B). Additionally, a heat exchanger (4010B) may be mounted on the motor-gearbox housing (4012B) and may be used in the step of liquid cooling the electric motor assembly (4002A), gearbox assembly (4006A), and / or inverter assembly (4004A) by cooling the liquid circulating throughout the electric motor assembly (4002A), gearbox assembly (4006A), and / or inverter assembly (4004A) to cool individual components. Fig. 40b It should be understood that while the inner circumference of the heat exchanger is depicted as being less than the outer circumference of the motor-gearbox housing, the heat exchanger (4010B) may extend over any distance less than the outer circumference of the motor-gearbox housing (4012B). Additionally, the inverter assembly housing (4014B) may be mechanically coupled to the rear of the motor-gearbox housing (4012B) and may have cooling fins (4024B) oriented toward the circumference of the inverter assembly housing (4014B). Additionally, the inverter assembly housing (4014B) may have a connection point to a power connection channel (4018B) at the outer edge of the inverter assembly housing (4014B) and behind the heat exchanger (4010B).

[0254] Fig. 40cThe present disclosure provides a schematic diagram of an exemplary electric propulsion system according to an embodiment of the present disclosure. The electric propulsion system (4000C) may include components such as an electric motor assembly (4002C) and a gearbox assembly (4006) housed within a motor-gearbox housing (4012C), and an inverter assembly (4004C) housed within an inverter assembly housing (4014C). Additionally, the electric propulsion system may include a propeller assembly (4008C) and a heat exchanger (4010C) fluidly coupled to the electric motor assembly (4002C) and the gearbox assembly (4006C) via a liquid path (4016C). Some embodiments may include a liquid path (4016C) containing a liquid used to cool, lubricate, or cool and lubricate the components fluidly coupled to the heat exchanger (4010C). In some embodiments, the heat exchanger (4010C) may be mounted directly or indirectly to the motor-gearbox housing (4012C). The liquid path (4016C) may include a distribution channel, a device for distributing liquid, or a cavity capable of delivering liquid, distributing the liquid to a component fluidly coupled to the heat exchanger (4010C), and recirculating the liquid to the heat exchanger (4010C). The liquid present in the liquid path (4016C) may collect heat from the component fluidly coupled to the heat exchanger (4010C) and transfer heat to the incoming air (4018C) passing through the heat exchanger (4010C). Thus, the embodiment may include a heat exchanger (4010C) positioned so that incoming air, which is encountered during flight or from the propeller assembly (4008C), can pass through and cool the liquid passing through the heat exchanger (4010C).

[0255] Fig. 40d [The present disclosure] provides a schematic diagram of an exemplary electric propulsion system according to an embodiment of the present disclosure. The electric propulsion system (4000D) is Fig. 40cIt may include a similar arrangement of components as illustrated and described in. However, the electric propulsion system (4000D) may include a gearbox assembly (4006D) located between an electric motor assembly (4002D) and a propeller assembly (4008D) connected to the first end of the motor-gearbox housing (4012D), having an inverter assembly (4004D) housed within an inverter assembly housing (4014D) connected to the second end of the motor-gearbox housing (4012D). The electric propulsion system (4000D) may also include an electric motor assembly (4002D) and a gearbox assembly (4006D) fluidly coupled to a heat exchanger (4010D) partially exposed to air (4018D) entering through a liquid path (4016D) for the purpose of lubricating and cooling the gearbox assembly (4006D) and the electric motor assembly (4002D).

[0256] The liquid paths (4016C and 4016D) are described with a high degree of generality as simple loops. However, it should be understood that the liquid paths may include branches, sub-loops, or other divided paths. Generally, the liquid can be circulated in any manner to efficiently lubricate and cool the various components present within the motor-gearbox housing (4012C and 4012D).

[0257] Fig. 41[Image] is a cross-sectional view of an electric propulsion system of a VTOL aircraft according to a disclosed embodiment. The electric propulsion system (4100) may include an inverter assembly (4104), a gearbox assembly (4106), and an electric motor assembly (4102) aligned along a main shaft (4110) mechanically connected to a shaft flange assembly (4112). The inverter assembly (4104), the gearbox assembly (4106), and the electric motor assembly (4102) may be located within the same housing as the motor-gearbox assembly housing (4114) and the inverter assembly housing (4116), where the inverter assembly housing (4116) is adjacent to the motor-gearbox assembly housing (4114). Additionally, a power connection channel (4118) may be connected to a high-voltage connector located in the inverter assembly housing (4116). In addition to these embodiments, a heat exchanger (4108) may be mounted in the motor-gearbox assembly housing (4114) and may be used along a distribution channel (not shown) to assist in the step of liquid cooling the electric motor assembly (4102), gearbox assembly (4106), and / or inverter assembly (4104) by cooling the liquid circulating throughout the electric motor assembly (4102), gearbox assembly (4106), and / or inverter assembly (4104) to cool individual components. In some embodiments, the inverter assembly, gearbox assembly, and electric motor assembly are shown to correspond to the described stacked assembly inverter assembly, planetary gearbox, and electric motor consisting of a stator and a rotor, but the drawings are examples and the inverter assembly, gearbox assembly, and electric motor assembly may be any type capable of achieving the same or similar functionality as described herein.

[0258] Figs. 42a-42b[This is a diagram of an exemplary electric propulsion system for a VTOL aircraft according to the disclosed embodiment. The electric propulsion system (4200) may be cooled using liquid cooling. The electric propulsion system (4200A) may include an electric motor assembly located within a motor assembly housing (4202A) and a gearbox assembly located within a gearbox assembly housing (4206A) aligned along a main shaft (4208A) connected to a shaft flange assembly (4210A). In some embodiments, the electric motor assembly may be located between the gearbox assembly and the shaft flange assembly (4210A). Additionally, an inverter assembly housing (4204A) may be adjacent to the gearbox assembly housing (4206A) and mechanically connected to a power connection channel (4214A). In some embodiments, a heat exchanger (4212A) may be coupled to the gearbox assembly housing (4206A) and the inverter assembly housing (4204A). Additionally, the heat exchanger (4212A) may be fluidically coupled to the electric motor assembly, gearbox assembly, and inverter assembly through a liquid channel to provide liquid for cooling and lubricating components within the electric motor assembly, gearbox assembly, and inverter assembly. Some embodiments may include a channel comprising channels, holes, and cavities capable of carrying liquid throughout the fluidly coupled components of the electric propulsion system (4200B).

[0259] Fig. 42b is a liquid cooled using a heat exchanger (4212B) fluidically coupled to an electric motor assembly, a gearbox assembly, and an inverter assembly. Fig. 42aAs discussed, a perspective view of an exemplary electric propulsion system (4200B) is illustrated. The exemplary electric propulsion system (4200B) may include an electric motor assembly located within a motor assembly housing (4202B) and a gearbox assembly housed in a gearbox assembly housing (4206B) aligned along a main shaft (4208B) mechanically coupled to a flange shaft assembly (4210B). Some embodiments may include a gearbox assembly housing (4206B) and a motor assembly housing (4202B) having a substantially circular profile with the same radius. The exemplary electric propulsion system (4200B) may also include a power connection channel (4214B) and an inverter assembly housed within an inverter assembly housing (4204B) having a substantially circular profile mechanically coupled to the gearbox assembly housing (4206B). Some embodiments may include an inverter assembly housing (4204B) having a radius larger than the radius of the gearbox assembly housing (4206B) and / or the motor assembly housing (4202B).

[0260] Figs. 43a-43dThis is a diagram and schematic illustration illustrating an exemplary electric propulsion system for a VTOL aircraft according to a disclosed embodiment. The electric propulsion system (4300A) may include a gearbox assembly (4306A), an electric motor assembly (4302A), and an inverter assembly (4304A) aligned along a main shaft (4316A) connected to a shaft flange assembly (4308A). The inverter assembly (4304A) may be located within an inverter assembly housing (4312A). Additionally, the gearbox assembly (4306A) and the electric motor assembly (4302A) may be located within a motor-gearbox assembly housing (4310A). Some embodiments may include an inverter assembly (4303A) located between the inverter assembly housing (4312A), the motor-gearbox assembly housing (4310A), and the shaft flange assembly (4308A). In this configuration, the main shaft (4316A) may pass through the gearbox assembly (4306A), the electric motor assembly (4302A), and the inverter assembly (4304A). Additionally, the power connection channel (4314A) may extend from the boom, wing, or fuselage of the aircraft through the motor-gearbox assembly housing (4313A) to the connection point of the inverter assembly housing (4312A).

[0261] Fig. 43b The air is cooled Fig. 43aA perspective view of an exemplary embodiment of an electric propulsion system (4300B) is shown as discussed. The electric propulsion system (4300B) may include an electric motor assembly (4302A) and a gearbox assembly (4306A) housed within a motor-gearbox housing (4310B), and an inverter assembly housed within an inverter assembly housing (4312B). The motor-gearbox housing (4310B) and the inverter assembly housing (4312B) may have substantially circular profiles having substantially the same radius and may be aligned along a main shaft (4316B) connected to a flanged shaft assembly (4308B). Some embodiments may include an inverter assembly housing (4312B) located between a motor-gearbox assembly housing (4310B) and a flanged shaft assembly (4308B), having a power connection channel (4314B) extending from the boom, wing, or fuselage of the aircraft through the motor-gearbox assembly housing (4310B) to a connection point of the inverter assembly housing (4312B). Additional embodiments may include a motor-gearbox housing (4310B) and an inverter assembly housing (4312B) having cooling fins (4320B and 4318B) on the outer surface of each housing, respectively. The cooling fins (4320B, 4318B) can transfer heat to external air passing through the cooling fins (4320B, 4318B) from components housed within the motor-gearbox housing (4310B) and the inverter assembly housing (4312B).

[0262] Fig. 43c [The present disclosure] provides a schematic diagram of an exemplary electric propulsion system (4300C) according to an embodiment of the present disclosure. The electric propulsion system (4300C) is Fig. 43a and Fig. 43bIt may include components of a similar arrangement as illustrated and described in [the document]. However, the electric propulsion system (4300C) may include a gearbox assembly (4306C) located between an electric motor assembly (4302C) and an inverter assembly (4304C) connected to a flange shaft assembly (4308C). In this configuration, a main shaft (4316A) (not shown) may pass through the electric motor assembly (4302C), the gearbox assembly (4306C), and the inverter assembly (4304C). Additionally, one or more power connection channels (4314C) may extend from the boom of the aircraft through the motor-gearbox assembly housing (4310C) to a connection point of the inverter assembly housing (4312C).

[0263] Fig. 43d [This] provides a schematic diagram of an exemplary electric propulsion system (4300D) according to an embodiment of the present disclosure. The electric propulsion system (4300D) Figs. 43a-43c It may include a similar arrangement and labeling of components as illustrated and described in [the document]. Fig. 43d Is Fig. 43c An electric propulsion system (4300D) similar to the electric propulsion system (4300C) is illustrated, wherein the inverter assembly housing (4312D) is connected to a power connection channel (4314D) extending from the boom of the aircraft and is adjacent to the flange shaft assembly (4308D) and the motor assembly housing (4310D). However, the motor assembly housing (4310D) accommodates an electric motor assembly (4302D) that provides torque to the flange shaft assembly (4308D) through a main shaft that travels through the inverter assembly (4304D) without gear reduction from the gearbox assembly.

[0264] Figs. 44a-44cThis is a schematic diagram illustrating an exemplary electric propulsion system for a VTOL aircraft according to a disclosed embodiment. The exemplary electric propulsion system (4400A) may include an inverter assembly (4404A) housed within an inverter assembly housing (4416A) located between a shaft flange assembly (4410A) and a separator plate (4408A). In addition to the inverter assembly housing (4416A), the separator plate (4408A) may be coupled to a motor-gearbox housing (4414A) that houses an electric motor assembly (4402A) and a gearbox assembly (4406A). In this configuration, the inverter assembly housing (4416A) may include an attachment point for a power connection channel (4420A) extending from the boom, wing, or fuselage of the aircraft. Additionally, this configuration may include a main shaft mechanically coupled to a shaft flange assembly (4410A) that moves through the inverter assembly housing (4416A) and, in some embodiments, from the inverter assembly (4404A) and the separator plate (4408A) to the electric motor assembly (4402A). Some embodiments may include a main shaft that extends from a first end of the motor-gearbox assembly housing (4414A), which is mechanically coupled to the separator plate (4408A), to a second end of the housing and, thus, through or past the gearbox assembly (4406A) to the electric motor assembly (4402A). Some embodiments may include a heat exchanger (4412A) fluidly coupled to the inverter assembly (4404A), the gearbox assembly (4406A), and the electric motor assembly (4402A) through a liquid flow path (4418A). The separator plate (4408A) can act to seal the upper part of the motor-gearbox assembly housing (4414A) through the end bell assembly and to seal the lower part of the inverter assembly housing (4416A) through the heating plate.The separator (4408A) may include grooves, holes, or other conduits configured to distribute liquid to cool the inverter assembly (4404A) and to cool and lubricate the gearbox assembly (4406A) and the electric motor assembly (4402A). The liquid flow path (4418A) may include the step of circulating the liquid to extract heat from the components of the inverter assembly (4404A), the gearbox assembly (4406A), and the electric motor assembly (4402A) and to transfer that heat to an airflow (4422A) passing through the cooling fins of the heat exchanger (4412A).

[0265] Fig. 44b [The present disclosure] provides a schematic diagram of an exemplary electric propulsion system (4400B) according to an embodiment of the present disclosure. The electric propulsion system (4400B) Fig. 44a It may include components of a similar arrangement as illustrated and described in [the image]. Fig. 44b Is Fig. 44aAn electric propulsion system (4400B) similar to the electric propulsion system (4400A) is illustrated, wherein the inverter assembly housing (4416A) is connected to a power connection channel (4420A) extending from the aircraft's boom, wing, or fuselage and is located between the flange shaft assembly (4410B) and the separator (4408B). However, the separator (4408B) may also be coupled to a motor-gearbox assembly housing (4414B) that accommodates a gearbox assembly (4406B) located behind the electric motor assembly (4402B) relative to the separator (4408B). Some embodiments may include a liquid channel (4418B) that fluidly couples a heat exchanger to the inverter assembly (4404B), the gearbox assembly (4406B), and the electric motor assembly (4402B). Additionally, the liquid flow path (4418B) may include the step of circulating a liquid to extract heat from the components of the inverter assembly (4404B), gearbox assembly (4406B), and electric motor assembly (4402B) and to transfer the heat to an air flow (4422B) passing through the cooling fins of the heat exchanger (4412B).

[0266] Fig. 44c [This] provides a schematic diagram of an exemplary electric propulsion system (4400C) according to an embodiment of the present disclosure. The electric propulsion system (4400C) is Figs. 44a-44b It may include components of a similar arrangement as illustrated and described in [the image]. Fig. 44c Is Fig. 44a The electric propulsion system (4400A) and Fig. 44b An electric propulsion system (4400C) similar to that of the electric propulsion system (4400B) is illustrated. However, the electric propulsion system (4400C) includes a direct drive system as discussed herein, and the motor assembly housing (4414C) accommodates an electric motor assembly (4402C) that provides torque to the shaft flange assembly (4410C) without gear reduction through a gearbox assembly.

[0267] The liquid passages (4418A, 4418B, and 4418C) are described with a high degree of generality as simple loops. In some embodiments, the liquid passages may include branches, sub-loops, or other divided paths. Generally, the liquid may be circulated in any manner to efficiently lubricate and cool the various components present within the motor-gearbox housing (4414A-C) and the inverter assembly housing (4416A-C).

[0268] Figs. 45a-45d is a schematic diagram illustrating an exemplary electric propulsion system of a VTOL aircraft according to a disclosed embodiment. The electric engine (4500A) may include an electric motor assembly housed within a circular motor assembly housing (4510A) having an inverter assembly housed in an inverter assembly housing (4512A) that is coupled to the outer surface of the motor assembly housing (4510A). Fig. 45a While the illustration shows an inverter assembly housing (4512A) tangentially coupled to the outer surface of a motor assembly housing (4510A), in some embodiments, the base of the inverter assembly housing (4512A) may be coupled to the outer surface of the motor assembly housing (4510A) in any configuration, including a base of the inverter assembly housing having a radius of curvature similar to the radius of the electric motor assembly housing (4510A). Additionally, the inverter assembly housing (4512A) may include a busbar (4516A) connected to the motor assembly housing (4510A) to supply alternating current to the electric motor assembly. The inverter assembly housing (4512A) may also include cooling fins mounted on a portion of the inverter assembly housing (4512A) opposite to the coupled portion of the inverter assembly housing (4512A). The cooling fins (4514A) may function to remove heat generated from components present within the inverter assembly and transfer that heat to an airflow through the cooling fins (4514A).

[0269] Fig. 45b... illustrates a perspective view of an exemplary embodiment of an electric engine (4500B) according to the present disclosure. The exemplary electric engine (4500B) is Fig. 45a As illustrated and described, it may include components of a similar array, such that similar numeric labeling Fig. 45a and Fig. 45b Similar components are included throughout. An example electric engine (4500B) may include an electric motor assembly housed within an electric motor assembly housing (4510B) coupled to an inverter assembly housing (4512B) that houses an inverter assembly. Additionally, the electric engine (4500B) may include a busbar (4516B) connected to the motor assembly housing (4510B) to supply alternating current to the electric motor assembly. Fig. 45a Similarly, the electric engine (4500B) may have an inverter assembly housing (4512B) comprising cooling fins (4514B) capable of removing heat generated from components present within the inverter assembly and transferring that heat to an external airflow through the cooling fins (4514B). Additionally, the inverter assembly housing (4512B) may include a connection point for a power connection channel (4518B) formed within the aircraft's boom, wing, or fuselage.

[0270] Fig. 45c This schematically illustrates an exemplary embodiment of an electric engine (4500C) according to the present disclosure. The exemplary electric engine (4500C) is Fig. 45a and Fig. 45b As illustrated and described, it may include components of a similar array, such that similar numeric labeling Fig. 45a , Fig. 45b and Fig. 45cIt corresponds to similar components across. The electric engine (4500C) may include a gearbox assembly (4506C) and an electric motor (4502C) housed within a motor assembly housing (4510C) mechanically coupled to an inverter assembly housing (4512C) that houses an inverter assembly (4504C). Fig. 45c As illustrated in the figure, some embodiments may consist of a gearbox assembly (4506C) located between the electric motor assembly (4502C) and the propeller assembly (4508C). In some embodiments, the power connection channel (4518C) may be connected to an inverter assembly housing (4512C) originating from the boom, wing, or other location within the aircraft.

[0271] Fig. 45d This schematically illustrates an exemplary embodiment of an electric engine (4500D) according to the present disclosure. The exemplary electric engine (4500D) is Figs. 45a-45c As illustrated and described, it may include components of a similar array, such that similar numeric labeling Figs. 45a-45c Similar components are included throughout. The electric engine (4500D) may include a gearbox assembly (4506D) and an electric engine (4502D) housed within a motor assembly housing (4510D) coupled to an inverter assembly housing (4512D) that houses an inverter assembly (4504D). Some embodiments may include a configuration in which the electric motor assembly (4502D) is positioned between the gearbox assembly (4506D) and the propeller assembly (4508D). In some embodiments, a power connection channel (4518D) may be connected to the inverter assembly housing (4512D) originating from a boom, wing, or other location within the aircraft.

[0272] Figs. 46a-46b[This is a schematic diagram illustrating an exemplary electric propulsion system for a VTOL aircraft according to the disclosed embodiment. The electric propulsion system (4600A) may include a gearbox assembly (4606A) and an electric motor assembly (4602A) housed within a motor assembly housing (4612A) coupled to an inverter assembly housing (4614A) that houses an inverter assembly (4604A). Some embodiments may include a gearbox assembly (4606A) located between the electric motor assembly (4602A) and the propeller assembly (4608A). Some embodiments may include a heat exchanger (4610A) coupled to the motor assembly housing (4612A) and fluidly coupled to the electric motor assembly (4602A) and the gearbox assembly (4606A) through a liquid passage (4616A). The liquid channel (4616A) can be used to extract heat from components present within the electric motor assembly (4602A) and the propeller assembly (4608A). The liquid channel (4616A) can transport the extracted heat to the heat exchanger (4610A), which transfers the heat to an airflow (4618A) passing through the cooling fins of the heat exchanger (4610A).

[0273] Fig. 46b This schematically illustrates an exemplary embodiment of an electric propulsion system (4600B) according to the present disclosure. The exemplary electric engine (4600B) is Fig. 46a As illustrated and described, it may include components of a similar array, such that similar numeric labeling Fig. 46a and Fig. 46bSimilar components are included throughout. The electric propulsion system (4600B) may include a gearbox assembly (4606B) and an electric motor assembly (4602B) housed within a motor assembly housing (4612B) coupled to an inverter assembly housing (4614B) that houses an inverter assembly (4604B). Some embodiments may include an electric motor assembly (4602B) located between the gearbox assembly (4606B) and the propeller assembly (4608B). Some embodiments may include a heat exchanger (4610B) coupled to the motor assembly housing (4612B) and fluidly coupled to the electric motor assembly (4602B) and the gearbox assembly (4606B) through a liquid channel (4616B). The liquid channel (4616B) may be used to extract heat from components present within the electric motor assembly (4602B) and the propeller assembly (4608B). The liquid channel (4616B) can transport heat extracted to the heat exchanger (4610B) by transferring heat to the air flow (4618B) passing through the cooling fins of the heat exchanger (4610B).

[0274] The liquid paths (4616A and 4616B) are described with a high degree of generality as simple loops. In some embodiments, the liquid paths may include branches, sub-loops, or other divided paths. Generally, the liquid may be circulated in any manner to efficiently lubricate and cool the various components present within the motor assembly housing (4612A and 4612B).

[0275] Figs. 47a-47b is a schematic diagram illustrating an exemplary electric propulsion system of a VTOL aircraft according to a disclosed embodiment. The electric propulsion system (4700A) may include an electric motor assembly (4702A) and a gearbox assembly (4706A) located within a motor-gearbox housing (4710A). Fig. 47aThe embodiments illustrated may include a main shaft that travels through or from an electric motor assembly (4702A) to a propeller assembly (4708A) located outside the motor-gearbox housing (4710A). Additionally, the gearbox assembly (4706A) may not share an axis with the main shaft used by the electric motor assembly (4702A) to provide torque to the propeller assembly (4708A) or with the electric motor assembly (4702A). In these embodiments, the gearbox assembly (4706A) may still provide gear reduction between the electric motor assembly (4702A) and the propeller assembly (4708A). Some embodiments may also include an inverter assembly (4704A) located in an inverter assembly housing (4712A) that is mounted directly or indirectly to the motor-gearbox housing (4710A). While the inverter assembly (4704A) is shown to be mounted on the outer edge of the motor-gearbox housing (4710A), in some embodiments, the inverter assembly may have a circular profile that wraps around or partially around the motor-gearbox housing (4710A). Additionally, some embodiments may include an inverter assembly housing (4704A) that can be coupled to the outer surface of the motor-gearbox assembly housing opposite the propeller assembly (4708A). In some embodiments, the electric motor assembly (4702A), gearbox assembly (4706A), and inverter assembly (4704A) may each have various components that create various volumes in each assembly, and thus the motor-gearbox housing (4710A) and inverter assembly housing (4712A) may have various profiles and volumes based on the individual assembly configurations.

[0276] Fig. 47b This shows a partial cross-sectional view of the electric propulsion system (4700B). Fig. 47b Is Fig. 47aAlthough they may be related, elements identified by similar numbers may not refer to the same elements across the drawings. Some embodiments of the electric propulsion system (4700B) may include a gearbox assembly (4706A) and an electric motor assembly (4702A) located in a common motor-gearbox housing (4702B) having a shaft (4712B) that moves the electric motor assembly (4702A). Some embodiments may include a propeller assembly mechanically coupled to the shaft (4712B). In some embodiments, the electric motor assembly (4702A) may include a rotor (4710B) having a magnet array (4708B) aligned along the shaft (4712B) and a stator (4704B) having stator windings (4706B). In some embodiments, the rotor (4710B) may be directly or indirectly connected to the auxiliary shaft (4716B) around the shaft (4712B) so that the auxiliary shaft (4716B) rotates at the same speed as the rotor (4710B). In addition to this example, an embodiment of the auxiliary shaft (4716B) may have a spline shaft that interfaces with a gearbox assembly (4706A) adjacent to the electric motor assembly (4702A), and the gearbox assembly (4706A) also interfaces with a shaft (4712B) that provides torque to the propeller assembly (4708A). As described herein, an embodiment of the gearbox assembly (4706A) may include at least a first gear (4722B), a second gear (4720B), and a gearbox shaft (4718B) connecting them. In some embodiments, the radius of the first gear (4722B) may be larger than the diameter of the second gear (4720B) or vice versa. Thus, the spline portion of the auxiliary shaft (4716B) can interact with the first gear (4722B) at the speed of the rotating rotor (4710B) and rotate it. The rotating first gear (4722B) can drive the rotation of the gearbox shaft (4718B) and the second gear (4720B).The second gear (4720B) of the gearbox assembly (4706A) may be interfaced with a portion of the shaft (4714B) having a radius different from the radius of a portion of the shaft (4712B) connecting to the propeller assembly (4708A). In this embodiment, the gearbox shaft (4718B) of the gearbox assembly (4706A) may be positioned to provide a gear reduction to the shaft (4712B), which does not share an axis with the shaft (4712B) or the electric motor assembly (4702A) but still provides torque to the propeller assembly (4708A).

[0277] Fig. 48[Image] is a schematic diagram illustrating an exemplary electric propulsion system for a VTOL aircraft according to the disclosed embodiment. The electric propulsion system (4800) may include an electric engine housed within an electric engine housing (4802) that is aligned along a shaft (4804) moving from the electric engine housing (4802) to a propeller assembly (4808) including a propeller (4810). In some embodiments, the electric propulsion system (4800) may include a heat exchanger (4806) fluidically coupled to a component of the electric engine through a liquid passage present within the electric engine housing (4802). Some embodiments may include an electric engine housing (4802) coupled to the boom (4816) of the aircraft through a device (4814) for indicating the position of the electric propulsion system. Some embodiments may also include a blade pitch actuator (4812) coupled to the rear of the electric engine housing (4802). The component of the electric engine may generate varying amounts of heat depending on the flight phase in which the aircraft is engaged. For example, since the components of an electric engine of a vertical take-off and landing aircraft may generate more heat during the hovering phase of flight than during the cruising phase, more airflow through the heat exchanger (4806) may be required during the hovering phase than during the cruising phase to cool the fluid used to cool and / or lubricate the components of the electric engine. Accordingly, some embodiments may include a boom (4816) containing a cavity (4818) in the boom, and the heat exchanger (4806) may be accommodated during the cruising phase. The cavity (4818) may act to block or reduce the airflow entering the heat exchanger during flight due to the reduction in air required to cool the system during various flight phases.

[0278] Examples may be further ...

Claims

Claim 1 An electric propulsion system comprising: an inverter including a printed circuit board assembly (PCBA); an electric motor assembly including a stator and a rotor; an assembly configured to rotate a propeller including a moving component and a stationary component; and a rotor position sensor comprising at least one sensor coupled to the PCBA, and a magnet positioned on the moving component, wherein the at least one sensor is configured to detect the magnetic field of the magnet through the stationary component. Claim 2 In paragraph 1, the PCBA is an electric propulsion system further comprising an integrated oil temperature sensor. Claim 3 In paragraph 2, an electric propulsion system in which an integrated oil temperature sensor is positioned to detect the temperature of the cooling oil. Claim 4 In paragraph 3, the electric propulsion system is configured such that the cooling oil cools at least one of a MOSFET or a power module. Claim 5 An electric propulsion system comprising an auxiliary speed sensor in any one of paragraphs 1 to 4. Claim 6 In paragraph 5, the auxiliary speed sensor is connected to the control panel of the electric propulsion system, electric propulsion system. Claim 7 An electric propulsion system according to any one of paragraphs 1 to 4, wherein the moving component is a gear and the magnet is positioned on the gear. Claim 8 In paragraph 7, the electric propulsion system is configured such that the gear transmits torque from the electric motor assembly to the propeller. Claim 9 In paragraph 7, the gear is an electric propulsion system that is a planetary carrier. Claim 10 An electric propulsion system according to any one of claims 1 to 4, wherein the fixed component comprises at least one of a heating plate or an end bell plate. Claim 11 An aircraft comprising: a boom; at least one electric propulsion system mounted on the boom, comprising a propeller; an inverter comprising a printed circuit board assembly (PCBA); an electric motor assembly comprising a stator and a rotor; an assembly configured to rotate the propeller comprising a moving component and a stationary component; and a rotor position sensor comprising at least one sensor coupled to the PCBA, and a magnet positioned on the moving component, wherein the at least one sensor is configured to detect the magnetic field of the magnet through the stationary component. Claim 12 In paragraph 11, the aircraft is a vertical take-off and landing (VTOL) aircraft. Claim 13 In paragraph 11 or 12, the PCBA further comprises an integrated oil temperature sensor, an aircraft. Claim 14 In paragraph 13, an aircraft in which an integrated oil temperature sensor is positioned to detect the temperature of the cooling oil. Claim 15 In paragraph 14, the aircraft, wherein the cooling oil is configured to cool at least one of a MOSFET or a power module. Claim 16 An aircraft comprising an auxiliary speed sensor in addition to the one in paragraph 11 or 12. Claim 17 In paragraph 16, the auxiliary speed sensor is connected to the control panel of the electric propulsion system of the aircraft. Claim 18 An aircraft, wherein, in paragraph 11 or 12, the moving component is a gear and the magnet is located on the gear. Claim 19 In paragraph 18, the gear is configured to transmit torque from the electric motor assembly to the propeller, in an aircraft. Claim 20 In paragraph 19, the gear is an aircraft that is a planetary carrier. Claim 21 An aircraft according to paragraph 11 or 12, wherein the fixed component comprises at least one of a heating plate or an end bell plate. Claim 22 A method for operating an electric propulsion system, comprising the steps of: operating an electric motor assembly including at least a stator and a rotor; providing power to the electric motor assembly by an inverter including a printed circuit board assembly (PCBA); operating an assembly including a moving component and a stationary component to rotate a propeller; and detecting the rotational position of the propeller using a rotor position sensor, wherein the rotor position sensor comprises: at least one sensor integrated into the PCBA; and a magnet located on the moving component, and the step of detecting the rotational position of the propeller comprises using the at least one sensor to detect the position of the magnet by detecting the magnetic field of the magnet through the stationary component. Claim 23 In paragraph 22, the PCBA further comprises an integrated oil temperature sensor, and a method for detecting temperature by the integrated oil temperature sensor. Claim 24 A method according to paragraph 23, further comprising the step of detecting the temperature of the cooling oil. Claim 25 A method according to claim 24, further comprising the step of cooling at least one of a MOSFET or a power module by cooling oil. Claim 26 A method comprising, in any one of claims 22 to 25, further the step of detecting the speed of the electric propulsion system by an auxiliary speed sensor connected to a control panel of the electric propulsion system. Claim 27 A method according to any one of paragraphs 22 through 25, wherein the moving component is a gear and the magnet is positioned on the gear. Claim 28 In paragraph 27, the method is configured such that the gear is configured to transmit torque from the electric motor assembly to the propeller. Claim 29 In paragraph 27, the above gear is a planetary carrier, method. Claim 30 A method according to any one of claims 22 to 25, wherein the fixed component comprises at least one of a heating plate or an end bell plate.

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