Electric propulsion system for delivering high torque

Abstract

A system to convert electrical power to torque having one or more motor controllers and an electric motor assembly (EMA) adapted to rotate a main shaft. Each motor controller adapted to receive high-voltage, direct-current (HVDC) and convert the HVDC to multiphase high-voltage, alternating-current (HVAC) output power at a fundamental frequency of about 10 hertz to about 1000 hertz, wherein each motor controller varies its respective multiphase HVAC output power in response to received power input commands. The EMA has a rotor assembly rotatable relative a stator module to rotate the main shaft, each rotor assembly having a plurality of magnets arranged to form a plurality of magnetic poles and each stator module has a plurality of stator windings wrapped about a projecting structure and configured to receive the HVAC power from the motor controllers. The main shaft of the electric motor assembly rotating at between 0-8000 revolutions per minute (RPM).

Description

ELECTRIC PROPULSION SYSTEM FOR DELIVERING HIGH TORQUEBACKGROUND

[0001] This disclosure relates to systems to convert electrical energy or power to torque and in an embodiment to an electric propulsion system (EPS) that includes one or more motor controllers to supply electrical power to one or more electric motors, electric motor modules, and / or electrical motor assemblies to generate torque to power, for example, aircraft.

[0002] Traditionally, aircraft, for example airplanes and / or helicopters, have used gas-powered engines to drive the propulsors to power the airplanes and / or helicopters. Gas powered engines for use in airplanes and / or helicopters have certain hazards associated with transporting and utilizing the highly combustible fuel that is necessary to power the engines in those systems. Gas powered engines also have exhaust gases that are not environmentally friendly and have performance characteristics that exhibit large variations at ambient conditions and with increasing altitude. It is desirable to have a propulsion system to provide high-torque to propulsors for aircraft that is highly reliable and has redundancy, but does not have the disadvantages of gas powered engines, such as for example the hazards associated with a highly combustible fuel, the large performance variations and deteriorating performance at high altitudes, and environmentally unfriendly exhaust gases dispensed at high altitudes.SUMMARY OF THE INVENTION

[0003] The summary of the disclosure is given to aid the understanding of an electric propulsion system (EPS) that includes one or more electric motor assemblies and one or more motor controllers, and their method of operation. The present disclosure is directed to a person of ordinary skill in the art. It should be understood that various aspects and features of the disclosure may advantageously be used separately in some instances, or in combination with other aspects and features of the disclosure in other instances.

[0004] In one or more embodiments, an electric propulsion system (EPS) to convert electrical energy or power to torque is disclosed. The EPS comprises one or more motor controllers, each motor controller adapted and configured to receive power controls and high-voltage, direct-current (HVDC) from power sources (e.g., batteries and / or fuel cells) and convert the HVDC from the power sources to high-voltage, alternating-current (HVAC). The EPS further includesone or more electric motors, also referred to as electric motor modules and / or electric motor assemblies, each electric motor having a main shaft for supplying torque, the electric motor assembly configured and adapted to receive power as HVAC from the motor controller and convert the electrical energy to rotational energy to rotate the main shaft to provide torque. In an embodiment the electric motor assembly rotates the main shaft in a range of 0-7000 revolutions per minute (RPM), preferably 0-8000 RPM, with an operating range of about 5000-7000 RPM, more preferably 6000-6200 RPM. The EPS in one or more embodiments, for example for implementation in helicopters, includes a drive train system (e.g., a gear train) that receives as input the high RPM of the main shaft and outputs lower RPM at a drive shaft to rotate the main rotor of a helicopter. In one or more arrangements the EPS includes an integrated cooling system that includes a fan / pump that preferably is directly driven by the main shaft of the electric motor assembly. The EPS propulsion system in one or more embodiments receives control input and in response the one or more motor controllers varies HVAC power to the one or more electric motor assemblies to vary torque and / or speed output of the one or more electric motor assemblies. In a representative application, the electric propulsion system (EPS) provides torque to and integrates with an aircraft propulsion system, e.g., to rotate the main rotor of a helicopter and optionally the tail rotor.

[0005] In one or more configurations, the EPS comprises one or more motor controllers, each motor controller configured to receive power input commands and to receive high-voltage, direct-current (HVDC) input power of between 400-850 DC volts and convert the HVDC input power to multiphase high-voltage, alternating-current (HVAC) output power at a fundamental frequency of about 10 hertz to about 1000 hertz, wherein each motor controller varies its respective multiphase HVAC output power in response to the power input commands received; and an electric motor assembly having a main shaft for supplying torque, the electric motor configured and adapted to receive input power as multiphase HVAC from the one or more motor controllers to rotate the main shaft, wherein the electric motor assembly has one or more rotor assemblies, preferably concentrically contained within, and rotatable relative to one or more stator modules to rotate the main shaft, each rotor assembly has a plurality of magnets arranged around an outer periphery of a hub to form between 14 to 32 magnetic poles and each stator module has a plurality of stator windings and a stator core having a plurality of spaced apartprojecting structures forming between 18 to 30 slots, each one of the plurality of stator windings wrapped about the projecting structure and configured to receive the multiphase HVAC power from the one or more motor controllers.

[0006] In an arrangement, the one or more motor controllers in combination generate between 160 kW and 500 kW of HVAC output power, and in a further arrangement each motor controller generates between 80 kW and 250 kW of HVAC output power. Each motor controller in an example embodiment outputs about 10 volts RMS to about 850 Volts RMS and about zero to about 700 amps RMS at the fundamental frequency range of about 10 Hertz to about 1000 Hertz.

[0007] In one or more embodiments, the EPS further comprises a cooling system preferably having a liquid coolant, wherein the liquid coolant is configured to flow through both the electric motor assembly and at least one of the motor controllers. Each of the one or more motor controllers in an example embodiment has a housing, wherein the liquid coolant flows through the housing of at least one of the motor controllers. The EPS in one or more configurations comprises at least two motor controllers and the system is configured so that the liquid coolant flows through at least two of the housings of the motor controllers in parallel and through the electric motor assembly preferably in series with the at least two motor controllers. In a further optional embodiment, the liquid coolant, preferably turbine oil, Hows through at least one of a group of the plurality of stator windings.

[0008] In one or more configurations, the liquid coolant flows through a first pathway through the at least one of the motor controllers and through at least one of the plurality of stator windings in the electric motor assembly and the liquid coolant flows through a second pathway in the electric motor assembly through at least one of a lubrication group consisting of: a bearing, a spline, a shaft coupling, and combinations thereof to lubricate the at least one of the lubrication group. The second pathway in an embodiment is pressurized. The first pathway through the electric motor assembly according to an approach is parallel to the second pathway through the electric motor assembly. The second pathway in an embodiment includes a drive end channel to lubricate at least one of a drive end lubrication group consisting of: a drive end bearing, a drive end spline, a drive end shaft coupling, and combinations thereof to lubricate the at least one of the drive end lubrication group and a lead end channel to lubricate at least one of a lead end lubrication group consisting of: a lead end bearing, a lead end spline, a lead end shaft coupling.and combinations thereof to lubricate the at least one of the lead end lubrication group. In an arrangement, the second pathway includes a spline conduit configured to deliver coolant fluid to a shaft coupling in the electric motor assembly and a separate bearing conduit configured to deliver coolant fluid to a bearing in the electric motor assembly. Optionally, the cooling system comprises one or more vents.

[0009] The liquid cooling system in one or more embodiments includes one or more temperature sensors and data from the temperature sensors is communicated to one or more of the motor controllers for processing and / or one or more pressure sensors and data from the pressure sensors is communicated to one or more of the motor controllers for processing. The cooling system according to another example further contains a reservoir to contain the liquid coolant, a conduit system to channel the liquid coolant at least between the one or more motor controllers and the electric motor assembly, and at least one pump to pump the liquid coolant. In an approach, a first end of the main shaft is connectable to a drive train that drives a propulsor of an aircraft and a second end of the main shaft directly drives a pump to circulate the liquid coolant in the cooling system. The cooling system in an embodiment circulates 25-70 liters per minute (LPM) of oil as the liquid coolant. Other embodiments, for example where the electric motor assembly is in parallel with the one or more motor controllers likely will have higher flow rates, for example between 70 and 130 LPM. In a further example aspect of EPS, the electric motor assembly is configured to receive fluid as a lubricant to lubricate one or more moving parts within the electric motor assembly, wherein the same fluid used as lubricant in the electric motor assembly is used as coolant in the cooling system. The electric motor assembly further in a further example includes a jet nozzle to spray the lubricant to lubricate one or more bearings that are configured to support the main shaft, wherein the jet nozzle receives the lubricant under pressure.

[0010] According to an example embodiment, the one or more motor controllers are configured to produce and supply two independent multi-phases of HVAC output power and each stator module in the electric motor is configured to receive at least two independent multiphases of HVAC output power from the one or more motor controllers. In a further aspect, a single motor controller having a single housing with a single cooling channel to receive liquid coolant produces and supplies the two independent multi-phases of HVAC output power, wherein the single motor controller contains two independent circuits, each to produce one of theindependent multiphase HVAC outputs. The hub of at least one rotor assembly according to an optional configuration has twisted blades to assist with moving air axially through the electric motor assembly and / or a set of radial vanes move air radially on the rotor to facilitate cooling the electric motor assembly.

[0011] The plurality of stator windings on at least one of the one or more stator modules according to one or more embodiments are arranged as at least two independent sets of a plurality of stator windings, each independent set of a plurality of windings is electrically isolated from the other set of a plurality of stator windings. A first independent set of a plurality of windings according to a further embodiment is spaced and separated from a second independent set of plurality of stator windings to resist magnetic coupling between sets of stator windings. In an arrangement, the first set of independent stator windings includes at least two groups of a plurality of stator windings, each of the plurality of stator windings in each group is electrically connected together and electrically isolated from the plurality of windings in the other groups. According to a further configuration, there are two independent sets of a plurality of windings in at least one of the one or more stator modules, wherein each independent set of stator windings has three groups of a plurality of stator windings, each of the plurality of stator windings in each group of each independent set of stator windings is electrically connected together and electrically isolated from each of the plurality of windings in each other group of stator windings.

[0012] The electric motor assembly in one or more approaches is configured to receive two independent supplies of three phase, high voltage, alternating current, and wherein the first independent supply of three phase, high voltage, alternating current is configured to supply the first independent set of three groups of a plurality of stator windings, each of the three groups of stator windings in the first set configured to receive a different phase of the first independent supply of three phase, high voltage, alternating current, and wherein the second independent supply of three phase, high voltage, alternating current is configured to supply the second independent set of three groups of a plurality of stator windings, each of the three groups of stator windings in the second set configured to receive a different phase of the second independent supply of three-phase, high-voltage, alternating current. In a further approach, the first independent set of a plurality of windings is positioned on a first half of the at least one ofthe one or more stator modules and the second independent set of a plurality of stator windings is positioned on the second half of the at least one of the one or more stator modules wherein the first half is spaced from and separated from the second half to resist magnetic coupling between the first and second independent sets of stator windings.

[0013] Each magnetic pole according to an embodiment of the EPS has at least three magnets with their magnetic poles oriented in different directions. The electric motor assembly in an example has at least two sets of three electrical connectors to receive HVAC from the one or more motor controllers. The EPS can optionally include a drive train (e.g., gearbox) that derives power from the electric motor assembly and drives a propulsor of an aircraft, wherein the drive train (e.g., the gearbox) is configured to receive fluid as a lubricant to lubricate one or more moving parts within the drive train (e.g., the gearbox), wherein the same fluid used as a lubricant in the drivetrain (gearbox) is used as coolant in the cooling system.

[0014] The EPS in an arrangement, further includes a gearbox that receives rotational power from the electric motor assembly and drives a propulsor of an aircraft, wherein the gearbox is configured to receive fluid as a lubricant to lubricate one or more moving parts within the gearbox, wherein the same fluid used as the lubricant in the gearbox is used as the liquid coolant in the liquid cooling system. The EPS in a configuration can further include a gearbox conduit system to provide the lubricant to the gearbox to lubricate the one or more moving parts within the gearbox, wherein the gearbox conduit system is parallel to a motor controller conduit system to provide the liquid coolant to both the electric motor assembly and the at least one of the motor controllers. Alternatively, in an embodiment, the gearbox conduit system is in series with a motor controller conduit system to provide the liquid coolant to both the electric motor assembly and the at least one of the motor controllers.

[0015] It is contemplated that the EPS in an implementation will be configured as a propulsion system, wherein the main shaft of the electric motor assembly is configured to supply torque to a propulsor of an aircraft. In a representative application, the electric propulsion system (EPS) provides torque to and integrates with an aircraft propulsion system, e.g., to rotate the main rotor of a helicopter and optionally the tail rotor.

[0016] The EPS can optionally further include two or more motor controllers, wherein the at least two motor controllers communicate over a high-speed bus, and the system is capable ofoperating if one of the two or more motor controllers is degraded, faulty, or inoperable. The EPS can optionally further include one or more system controllers for receiving control input and outputting power input commands to the one or more motor controllers, and each motor controller optionally has at least two digital Controller Area Network communication interfaces to receive power input commands, wherein at least one the digital Controller Area Network communication interfaces is redundant. Each motor controller receives at least one of a group consisting of: temperature data, pressure data, and combinations thereof from the electric motor assembly. In a further aspect, the one or more motor controllers can optionally receive information on the main shaft of the electric motor assembly including at least one of the group consisting of speed, angular position, and combinations thereof.

[0017] The system in an embodiment uses a liquid cooling system for the electric motor assembly (e.g., the one or more electric motors or electric motor modules) as well as for the one or more electric motor controllers and in an aspect uses the same coolant fluid, preferably a silicon or turbine oil, to flow through both the one or more electric motor assemblies and the one or more motor controller(s). In an aspect, the same coolant fluid flows parallel through the two or more motor controllers, but serially through the one or more electric motor assemblies before or after the two or more motor controllers. The coolant fluid can flow serially or parallel through the plurality of electric motor assemblies.BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The various aspects, features, and embodiments of an EPS and its method of operation will be better understood when read in conjunction with the figures provided. Embodiments are provided in the figures for the purpose of illustrating aspects, features, and various embodiments of the EPS including an electric motor controller, an electric motor assembly, an optional integrated cooling system, and an optional drive train (e.g., gearbox) to drive the propulsor of an aircraft, and their operation, but the disclosure should not be limited to the precise arrangement, structures, assemblies, subassemblies, systems, mechanisms, devices, components, features, aspects, embodiments, methods, processes, and / or uses shown, and the arrangement, structure, assembly, subassembly, system, mechanisms, devices, components, features, aspects, embodiments, methods, processes, and shown may be used singularly or in combination withother arrangements, structures, assemblies, subassemblies, systems, mechanisms, devices, components, features, aspects, embodiments, methods, and / or processes, or for other uses.

[0019] FIG. 1 shows a perspective view of an example embodiment of an electric propulsion system (EPS) having two motor controllers electrically connected to an electric motor assembly that is adapted for use in powering a propulsor driven aircraft.

[0020] FIG. 2 shows an embodiment of a helicopter in which the EPS system of FIG. 1 can be implemented to power the helicopter.

[0021] FIG. 3 is a schematic diagram of an embodiment of an optional cooling / lubricant system and venting system of the EPS of FIG. 1.

[0022] FIG. 4 is a schematic diagram of another embodiment of an optional cooling / lubricant system and venting system of the EPS of FIG. 1.

[0023] FIG. 5 is a schematic diagram of further embodiment of an optional cooling / lubricant system and venting system of the EPS of FIG. 1.

[0024] FIG. 6 shows a front perspective view of an electric motor assembly in the example embodiment of the EPS of FIG. 1.

[0025] FIG. 7 shows a side view of an electric motor assembly in the example embodiment of the EPS of FIG. 1.

[0026] FIG. 8 shows a back or rear perspective view of an electric motor assembly in the example embodiment of the EPS of FIG. 1.

[0027] FIG. 9 shows an exploded front perspective view of the electric motor assembly of an example EPS.

[0028] FIG. 10 shows a front perspective view of a rotor assembly concentrically surrounded by a stator module of the electric motor assembly of the EPS of FIG. 1.

[0029] FIG. 11 shows a back perspective view of a rotor assembly concentrically surrounded by a stator module of the electric motor assembly of the EPS of FIG. 1.

[0030] FIG. 12 shows a perspective view of an embodiment of a rotor assembly of the electric motor assembly of the EPS of FIG. 1.

[0031] FIG. 13 shows a side view of a portion of the rotor assembly of FIG. 10.

[0032] FIG. 14 shows an end view of a stator module of the electric motor assembly of the EPS of FIG. 1.

[0033] FIG. 15 shows a front view of a portion of the stator assembly used in an embodiment of the electric motor assembly of the EPS of FIG. 1.

[0034] FIG. 16 shows a cross-sectional view of the electric motor assembly of the EPS of FIG.1.

[0035] FIG. 17 shows a cross-sectional view of a supply line to a drive (front) end bearing assembly in the electric motor assembly of the EPS of FIG. 1.FIG. 18 shows an enlarged cross-sectional view of the drive (front) end bearing assembly identified in FIG. 16 by box A.

[0036] FIG. 19 shows a cross-sectional view of the supply line and drain for the drive (front) end bearing assembly of the EPS of FIG. 1.

[0037] FIG. 20 shows a cross-sectional view of a supply line to a lead (rear) end bearing assembly in the electric motor assembly of the EPS of FIG. 1.

[0038] FIG. 21 shows an enlarged cross-sectional view of the lead (rear) end bearing assembly identified in FIG. 16 by box B.

[0039] FIG. 22 shows a cross-sectional view of the supply line and drain for the lead (rear) end bearing assembly of the EPS of FIG. 1.FIG. 23 shows a back right-side perspective view of the electric motor assembly in the example embodiment of the EPS of FIG. 1 incorporating an optional integrated cooling system.

[0040] FIG. 24 shows a back left-side perspective view of the electric motor assembly in the example embodiment of the EPS of FIG. 1 incorporating the optional integrated cooling system of FIG.23.

[0041] FIG. 25 is a top perspective view of the electric motor assembly in the example embodiment of the EPS of FIG. 1 incorporating the optional cooling system of FIG.23.

[0042] FIG. 26 is a rear perspective view of another example embodiment of an electric motor assembly with another embodiment of an optional cooling system for use in an EPS.

[0043] FIG. 27 is a rear perspective view of the example embodiment of the electric motor assembly with optional cooling system of FIG.26 for use in an EPS with portions shown in see through to illustrate the optional cooling system.DETAILED DESCRIPTION

[0044] The following description is made for illustrating the general principles of the invention and is not meant to limit the inventive concepts claimed herein. In the following detailed description, numerous details are set forth in order to provide an understanding of an electric propulsion system (EPS), its architectural structure, components, subsystems, and methods of operation, particularly configured to power a propulsor driven aircraft (e.g., a helicopter), however, it will be understood by those skilled in the art that different and numerous embodiments of the EPS, its architectural structure, its components and subsystems, its methods of operation, and its uses may be practiced without those specific details, and the claims and invention should not be limited to the arrangements, structures, embodiments, assemblies, subassemblies, mechanisms, features, functional units, circuitry, processes, methods, aspects, features, details, or uses specifically described and shown herein. Further, features, aspects, functions, circuitry, mechanisms, details, and embodiments described herein can be used in combination with other described features, aspects, functions, circuitry, details, mechanisms, and / or embodiments in each of the various possible combinations and permutations.

[0045] Unless otherwise specifically defined herein, all terms are to be given their broadest possible interpretation including meanings implied from the specification as well as meanings understood by those skilled in the art and / or as defined in dictionaries, treatises, etc. It should also be noted that, as used in the specification and the appended claims, the singular forms "a," "an" and "the" include plural referents unless otherwise specified.

[0046] A multi-use electric propulsion system (EPS) 100 is shown in FIG. 1 and by schematic block diagrams in FIGS. 3-5. which can be used to power the main propulsion system (e.g., main rotor 107) in an electric aircraft 110, for example the helicopter 105 shown in FIG. 2. While the system is described with reference as an EPS 100 and for use to power a helicopter 105, it should be appreciated that the system is not so limited and has many uses and applications. The EPS 100 in one or more embodiments comprises an electric motor assembly 110 that provides the mechanical output to rotate the main propulsor or propulsors of the aircraft (e.g., the main rotor 107 of the helicopter 105); and one or more motor controllers 180 that convert aircraft control inputs and electrical power from on-board energy sources, e.g., batteries, to the power, e.g., alternating-current (AC), required by the electric motor assembly 110. Theone or more motor controllers 180 receive control input and electrical power resulting in the delivery of electrical power, for example in the form of high voltage, alternating current (HVAC), to the one or more electric motor assemblies 110, and in response mechanical torque and power are generated at the main shaft 120 of the electric motor assembly 110. An optional system controller not shown can be included in EPS 100 that forms in an aspect an aircraft interface between the systems of the aircraft 105 and the EPS 100, e.g.. the motor controller(s) 180. Other additional components may be included, and the EPS 100 is not limited to the arrangement or type of components illustrated in FIGS. 1 and 3-5.

[0047] FIGS. 1 and 3-5 show EPS 100 with two motor controllers 180, an electric motor assembly 110, and an optional cooling system 210. More or less motor controllers 180 and / or more or less electric motor assemblies 110 are contemplated for the EPS 100. The electric motor assemblies 110, the motor controllers 180, and the optional cooling system 210 as discussed in this application can take many forms. In a preferred embodiment, the EPS 100 is a high RPM output system, where the main shaft 120 of the electric motor assembly 110 rotates at 0-8000 rpm to obtain greater output power.

[0048] In an arrangement, front (drive) end 122 of the main shaft 120 of the electric motor assembly 110 is attached to a drive train (e.g., a gear box 190) to increase and / or decrease the rotational speed of the drive shaft (output) of the drive train that rotates the main propulsor of the aircraft. That is, EPS 100 in one or more configurations optionally includes a main rotor gear box 190 as shown in FIG. 5, more specifically in an embodiment a reduction gear box 190, which in one or more arrangements is coupled to the main shaft 120 of the electric motor assembly 110. In a specific example, the rotational speed (RPM) of the main shaft 120 of the electric motor assembly 110 that is input (e.g., from the front (drive) end 112 of the electric motor assembly 110) to the gear box 190 is higher than the rotational speed (RPM) of output drive shaft 194 of the gear box 190 and part of drive train of the helicopter 105 so that output drive shaft 194 rotates at rotational speeds (RPM) appropriate for helicopters (e.g., helicopter 105), for example, around 400 to 420 rpm for the main rotor (e.g., main rotor 107) of the helicopter (e.g., helicopter 105). In an arrangement, a drive train spline coupling 121 at the front (drive) end 122 of the main shaft 120 couples main shaft 120 to the reduction gear box 190, e.g., to an input drive shaft 192 of the reduction gear box 190, to rotate the propulsor (e.g., main rotor 107) of the aircraft 105. Inone or more arrangements, there would be a separate power take-off from the power train (e.g., the helicopter’s main gear box) to rotate the tail rotor 108 of the helicopter.

[0049] Weight and power output (e.g., power density) of EPS 100 is important in configurations for aircraft, including helicopter 105. A power to weight ratio for the electric motor assembly 110 in one or more embodiments is in a range of 4 kW / kg to 11 kW / kg, while the power to weight ratio for EPS 100, including optional cooling system 210 (including the coolant fluid 212) is in a range of 3.8 kW / kg to 5.5 kW / kg. In an embodiment, the weight of EPS 100 is less than 92 kg, with a power output in the range of 160kW to 500kW. where in an embodiment each motor controller 180 outputs 80kW to 250kW, so that the two motor controllers 180, 180’ produce 160kW to 500kW (2 x 80-250 kW) in a 2x3 phase configuration. In an arrangement, the weight of the EPS 100 is not more than 92 kg and the power output is 380 kW. EPS 100 outputs up to 8000 RPM at main shaft 120, with a typical operating range of 5000-7000 RPM, more preferably about 6000-6200 RPM of main shaft 120. The motor controllers 180 each receive high-voltage, direct-current (HVDC) 182, typically in a range of 400 VDC to 850 VDC.

[0050] Packaging and size of EPS 100 is also an important consideration in configurations for aircraft. In an embodiment, the electric motor assembly 110 has a diameter D in a range of 250mm to 500mm and a width W in a range of 300 mm to 430mm, where each of the motor controllers 180 have a length in a range of 330mm to 380mm, a width in a range of 330mm to 380mm, and a height in a range of 60mm to 100mm, where the optional cooling system 210 is positioned on the rear end 114 of the electric motor assembly 110. In one or more embodiments, EPS 100 (with or without the drive train / gear box) fits into a bay having a length in a range of 400mm to 1000mm, a width in a range of 300mm to 700mm, and a height in a range of 350mm to 500mm.

[0051] Aircraft 105 has on-board components, including electric power sources, e.g., electric batteries and / or fuel cells, preferably high-voltage power sources and low- voltage power sources, and a power supply management system. The aircraft systems and components may further include a power distribution unit or PDU that facilitates the distribution of electric power to the components of the EPS 100, including preferably the motor controllers 180, 180’ shown in FIGS. 1 and 3-5. The aircraft systems and components in an embodiment further include an aircraft interface to provide control inputs to the EPS 100.

[0052] In the embodiment of EPS 100 in FIGS. 1 and 3-5, high-voltage, direct-current (HVDC) 182, e.g., 400-850 volts, is supplied to the motor controllers 180, e.g., from PDU and / or power / energy sources, and the motor controllers 180 convert the incoming HVDC 182 to high-voltage, alternating-current (HVAC) 184 that is supplied to the electric motor assembly 110. The HVAC power 184 supplied to the electric motor assembly 110 is converted to mechanical energy that turns the main shaft 120 which drives (rotates), in this example through a reduction gear box 190, the propulsor 107 (e.g., main rotor 107) of the aircraft 105. Each motor controller 180, 180’ shown in FIGS. 1 and 3-5, in one or more embodiments, supplies multiphase HVAC 184, and in an aspect three-phase HVAC 184, to electrical connectors 115 on electric motor assembly 110, shown in FIGS. 1, 6-9, 16, and 23-27, where electrical connector 115 receives a first phase 127 of HVAC 184, electrical connector 115’ receives a second phase 128 of HVAC 184, and electrical connector 115” receives a third phase 129 of HVAC 184. In this regard, electric motor assembly 110 receives two separate three phase HVAC 184 inputs, each three phase HVAC 184 from first motor controller 180 and three phase HVAC 184’ from second motor controller 180’.First motor controller 180 in one or more embodiments is the same as, or substantially the same as, the second motor controller 180’. In an embodiment, a single motor controller 180 can produce via two separate circuits (or through one or more common circuits, components, and / or features), the two separate, three phase HVAC 184, 184’ supplied to the electric motor assembly 110.

[0053] Preferably each motor controller 180 is configured to supply high-power HVAC 184 of about 80 to about 250 kilowatts (kW) at a fundamental frequency of about 10 Hertz (Hz) to about 1000 Hz to its corresponding electrical connector 115 on electric motor assembly 110. Each motor controller 180 in an embodiment independently supplies multi-phase, preferably three-phase, high power HVAC 184 preferably to separate electrical connectors 115 connected to separate electrical winding 135 in the electric motor 110. The electrical windings 135 or stator windings 135 in this application can take many forms, including the construction and configuration of, and share features with, the stator windings as described and taught in U.S. Patent application No. 16 / 888,824 filed on May 31, 2020, and / or PCT / AU2018 / 050553 (WO 2018 / 218314), the entirety of both of which are incorporated by reference. Other constructions, arrangements, and / or configurations are contemplated for stator windings 135.

[0054] Should one of the motor controllers 180 fail (e.g., the motor controller circuitry fails), the electric motor assembly 110 would still be supplied with power 184, e.g., HVAC power 184, from the other motor controller, and the electric motor 110 would remain operational and provide torque to the main shaft 120 and the propulsor element 107 (e.g., main rotor 107) of the aircraft 105. In addition, should one of the separate electrical windings 135 in the electric motor assembly 110 fail, then the electric motor assembly 110 would still remain operational by way of the remaining operational electrical (stator) windings 135 in the electric motor assembly 110.

[0055] The motor controllers 180, and optionally the system controller, in a configuration also receives low-voltage, direct-current (DC), e.g., 12-50 Volts (V) DC, more preferably about 28 V DC. The LVDC can be supplied by an independent direct-current (DC) power source (e.g., a low voltage battery) separate from the high voltage electric power source, e.g., high-voltage DC batteries. The motor controllers 180 or DC-DC step down converters (not shown) can also be utilized to convert the high-voltage, direct-current (HVDC) power source to LVDC for use by the motor controllers 180. or for use by the system controller. The LVDC supplied to the one or more motor controllers 180 in an aspect is used to supply low-voltage power to the circuits in the motor controller 180 to provide control and monitoring functions from inputs and feedback as will be discussed.

[0056] Electric motor assembly 110, and subassemblies and components thereof, are shown in FIGS. 6-16. Electric motor assembly 110 includes, for example, one or more stators, stator assemblies, and / or stator modules 130, one or more rotors or rotor assemblies 150, and a common or main shaft 120. The electric motor assembly 110 preferably also includes one or more shaft bearings 125 mounted on the main shaft 120 for supporting the main shaft 120. In an embodiment, the electric motor assembly 110 also includes a front port 157 and front filter assembly and / or a rear port 159 and rear filter assembly. The ports 157, 159 permit air to enter the electric motor assembly 110 to facilitate cooling electric motor assembly 110, while the filter assemblies preferably prevent debris and the like from entering and interfering with the rotating and moving components and systems in the interior of the electric motor assembly 110.

[0057] The housing 119 of the electric motor assembly contains rotor assembly 150, the main shaft 120, and preferably the one or more shaft bearings 125. In one or more embodiments, the outer casing of the stator module 130 forms part of a housing 119 for the electric motor assembly110. In an embodiment, front plate 111 forms front end 112 of electric motor assembly 110 while rear plate 113 forms rear end 114 of electric motor assembly 110; and the outer casing of the stator module 130 form a structural housing 119 for the electric motor assembly 110. The front and rear plates 111, 113 provide structure to transfer loads, propulsor forces, and moment and torque reactions from the main shaft 120 and bearings 125. The housing 119, in one or more embodiments, has one or more motor mounts 117, preferably replaceable motor mounts, attached thereto. The motor mounts 117 connect the electric motor assembly 110 to the aircraft. The motor mounts 117 preferably are removeably-connected to the housing 119 and can be replaced with motor mounts 117 of different configurations and sizes to permit the electric motor assembly 110 to be mounted in different configurations for different motor bays, e.g., aircraft motor bays. Forces and moments are transmitted from the motor main shaft 120 to the housing 119, to the motor mounts 117, and to the supporting structure, e.g., aircraft structure.

[0058] The housing 119 further includes electric power connectors 115 to receive incoming electric power. In the embodiment of electric motor assembly shown in FIGS. 6-16. housing 119 has two different sets of electric connectors 115 to receive two separate three phase HVAC inputs 184, 184’ from two different motor controller circuits in two motor controllers 180. The power supplied to the electric power connectors 115 is routed to stator windings 135 in the stator module 130 as discussed in more detail below.

[0059] The rotor assembly 150 as shown in FIGS. 9-13, include the supporting rotor structure or rotor hub 155 that has permanent magnets 160 associated with, preferably mounted to, the rotor hub 155, and, in a preferred embodiment, retention band 156 to facilitate retaining the permanent magnets 160 on the rotor structure / hub 155. The rotor hub 155 can be formed with one or more, preferably a plurality of twisted blades 158 (e.g., helically shaped (fan) blades) and openings which are configured to move air axially through electric motor assembly 110 as rotor assembly 150 rotates. In an embodiment, as twisted blades 158 rotate with rotor hub 155 air enters housing 119 of electric motor assembly 110 through either front port 157 or rear port 159, flows axially through the rotor hub (e.g., though openings between the blades 158), and exits housing 119 of electric motor assembly 110 through the other of either the front port 157 or rear port 159.Blades 158 facilitate an increase of air that flows axially through electric motor assembly 110 to assist with cooling electric motor assembly 110. Additionally, and / or alternatively, the hub of atleast one rotor assembly in an arrangement has one or more radial vanes to move air radially on to the rotor to facilitate cooling the electric motor assembly. It should be clear to a person of ordinary skill in the art that the rotor structure 155 can have magnets 160 mounted on the exterior surface (circumference) 151 of the rotor hub 155 or interior surface 154 of the rotor hub 155 encased in ferromagnetic material in an arrangement typical of Interior Permanent Magnet (IPM) machines.

[0060] The rotor assembly 150, more specifically the rotor hub 155, is preferably non-rotatably attached, e.g., rotatably fixed, to the main shaft 120, either indirectly or directly, so as to rotate the main shaft 120. That is, rotating the rotor assembly 150 or rotor hub 155 causes the main shaft 120 to rotate. In a preferred embodiment, the stator module 130 and rotor assembly 150 are located concentrically about the main shaft 120. The rotor assembly 150 is mounted inside and rotates relative to the stator assembly / module 130. The concentric stator module 130 and associated rotor assembly 150 form a motor module 126. The shaft bearings 125 preferably are also mounted about the main shaft 120. In a preferred embodiment, the electric motor assembly 110 is a permanent magnet synchronous machine (PMSM). The torque output of the main shaft 120 is used as input into a drive train where a draft shaft of the drivetrain drives a propulsor (e.g., main rotor 107 of helicopter 105) attached to the electric motor assembly 110.

[0061] The rotor assembly 150 in an embodiment as shown in FIGS. 12-13 has a plurality of permanent magnets 160 arranged along the outer circumference 151 of the rotor structure 155 to employ a Halbach array such that the magnetic field 152 of the rotor assembly 150 is reinforced on the working side 153 of rotor assembly 150 and cancelled on the back side 154 of the rotor assembly 150. By arranging the magnetic poles of the magnets 160 around the outer circumference 151 of the rotor hub 155 to increase the strength of the magnetic field 152 on the working side 153 of the rotor assembly 150 where the air gap 149 between the rotor assembly 150 and the corresponding stator module 130 is located (see FIG. 13), allows the reduction or removal of the back iron on the back side 154 of the rotor hub 155 that would normally be required to redirect the magnet field, thereby reducing the weight of the rotor assembly 150.

[0062] In a preferred embodiment the Halbach array is constructed using three (3) magnets 160 per pole as shown in FIGS. 12-13. For example, magnets 162, 164, and 166 form a north pole 161 where magnet 162 is positioned to have its north pole and magnetic flux directed up (towardstator assembly not shown) as shown by arrow 163 while adjacent magnet 164 is angularly positioned to have its north pole and magnetic flux angularly directed toward magnet 162 and up as shown by arrow 165, and while adjacent magnet 166 is angularly positioned to have its north pole and magnetic flux angularly directed toward magnet 162 and up as shown by arrow 167. Similarly, magnets 172, 174, and 176 form a south pole 171 where magnet 172 is positioned to have its south pole 171 and magnetic flux directed down (away from stator assembly not shown) as shown by arrow 173 while adjacent magnet 174 is angularly positioned to have its south pole and magnetic flux directed toward magnet 172 and down as shown by arrow 175 and adjacent magnet 176 is angularly adjusted to have its south pole and magnetic flux directed toward magnet 172 and down as shown by arrow 177. The north poles 161 and south poles 171 formed by the three magnet sets alternate as shown in FIGS. 12-13 around the circumference 151 of the rotor assembly 150.

[0063] In a Permanent Magnet Synchronous Machines (PMSM) the poles refer to the number of magnetic poles, e.g.. north pole 161, south pole 171 arranged in a circular array around the circumference 151 of the rotor hub 155, where each north pole counts as one pole and each south pole counts as one pole In an embodiment, the number of magnet poles that the rotor assembly 150 forms is an even number between about 10 and 32 poles. In a more specific embodiment, the number of magnetic poles is between about 14 to 18 poles. For example, sixteen (16) poles means that there are sixteen (16) alternating north and south poles (each pole in an embodiment formed by three magnets) positioned around the rotor hub 155. It should be appreciated that the number of poles can be more or less, and the number of magnets 160 forming the poles can also be more or less than the three magnets forming the poles in the embodiments of FIGS. 12-13.

[0064] The rotor assembly 150 in an arrangement also preferably includes a retention band or sleeve 156 applied over the magnets 160 to facilitate and help retain the magnets 160 on the rotor hub 155. In an aspect the retention band 156 is carbon fiber, or other material so as not to interfere with the magnetic flux of the magnets 160. In one or more aspects the width or working length WL of the rotor assembly 150 is between about 60 mm to about 200 mm. The stacks of magnets 160 are about 35 mm to about 100 mm in length and about 7 mm to about 20 mm wide. The radius R of the rotor hub 155 to the outer surface of the magnets 160 is between about 100 mm to about 200 mm. In an embodiment, the rotor hub 155 is a titanium alloy or other non-magnetic material, e.g., carbon fiber, to avoid interference with the magnetic fields created by the magnets 160.

[0065] The electric motor assembly 110 includes a stator module or assembly 130 that contains stator windings 135, stator core 140, insulation 146, stator teeth (e.g., projecting structure) 145, and the cooling geometry (e.g., stator cooling channels 142) to remove heat from the stator module 130 as shown in FIGS. 12-13. The stator module 130 surrounds the rotor assembly 150 and the main shaft 120. While the electric motor assembly 110 is shown in FIGS.9-11 and 16 as having one stator module 130, it will be appreciated that more or less stator modules can be provided.

[0066] Referring to FIGS. 1, 7-8, 16, and 23-27, the electric motor assembly 110 has at least one set of electrical connectors 115 to receive alternating-current input power, preferably high-voltage, alternating-current (HVAC) 184, 184’. More preferably, the electric motor assembly 110 has one or more sets of electrical connectors 115 to receive multi-phase alternating current, and in an aspect multi-phase, HVAC 184, 184’ of about 10 to about 850 volts (RMS), more preferably about 10 to about 560 volts RMS of alternating-current. This alternating current is typically about 10 to 700 amperes (RMS), more preferably 10 to 500 Amperes (RMS). Both the supplied RMS voltage and current are dependent on operating speed and commanded torque from the motor (e.g., the operating point of the motor). The supplied voltage is typically Pulse Width Modulated (PWM) voltage from motor controller 180, with typical modulation schemes such as Sine PWM (SPWM), Third Harmonic Injection PWM (THPWM or THIPWM) or Space Vector PWM (SVSPM) - schemes well known to a person skilled in the art.

[0067] In an embodiment, each set of connectors 115 receives three-phase, alternating current, preferably three-phase HVAC 184. The alternating-current delivered to the one or more set of connectors 115 is delivered to multiple stator windings 135 configured about the stator core 140.The alternating-current flows through the multiple stator winding 135 and creates an electromagnetic field which will be used to rotate the one or more rotor assemblies 150 as described below. The stator windings 135 include conductive wire, for example copper wire (e.g., insulated copper wire), typically wrapped in multiple loops / turns to form a coil 148, typically wrapped about a core (projecting) structure or stator tooth 145. A plurality of stator core structures orstator teeth 145 are attached to or form the stator structure 140. The stator windings 135 create an electro-magnetic field when current runs through the wire / coil 148.

[0068] Each stator module 130 preferably contains at least one set of multi-phase windings 135, e.g., three-phase stator windings configured about the stator core 140 and arranged so every fourth winding 135 receives the same phase of alternating-current. For example, a first stator winding 131 is arranged on the stator core 140 to receive a first phase of alternating current 127, while a second stator winding 132 is arranged on the stator core 140 adjacent to the first stator winding 131 receives a second phase of alternating current 128 that is phase shifted 120 degrees from the first phase of alternating current 127, and a third stator winding 133 is arranged on the stator core 140 adjacent to the second stator winding 132 receives a third phase of alternating current 129 that is phase shifted 120 degrees from the second phase of alternating current 128. Each of the first stator windings 131, second stator windings 132, and third stator windings 133 are electrically isolated and receive a different phase of alternating-current, preferably a different phase of HVAC. For example, a fourth stator winding 136 is arranged on stator core 140 adjacent third stator winding 133 and is electrically connected in series to the first stator winding 131 and receives first phase alternating-current 127, while a fifth stator core 137 is arranged on stator core 140 adjacent fourth stator winding 136 and is electrically connected in series to second stator winding 132 and receives second phase alternating-current 128, and a sixth stator winding 138 is arranged on stator core 140 adjacent fifth stator winding 137 and is electrically connected in series to the third stator winding 133 and receives third phase alternating-current 129.

[0069] In this regard, a first group of multiple first stator windings, e.g., 131. 136, are connected in series and receive a first phase of alternating current, preferably first phase HVAC 127, a second group of multiple second stator windings, e.g., 132, 137, are connected in series and receive a second phase of alternating current, preferably second phase HVAC 128, and a third group of multiple third stator windings, e.g., 133, 138, are connected in series and receive third phase of alternating current, preferably third phase HVAC 129. Additionally, groups of multiple windings can alternatively be connected in parallel to each other, e.g., the first group of multiple windings is connected in parallel with the second group and third group of multiple windings. While the above embodiment has described the use of three-phase stator windings 135, e.g.,three groups of multiple stator windings 135, receiving three-phases of alternating-current, it should be appreciated that in one or more embodiments the stator windings 135 could be configured for more or less phases of AC input, for example two or four phases of AC input, where in an aspect the degree of phase shift could be altered as per the design configuration.

[0070] In an embodiment, the stator windings consist of one or more groups of multi-phase winding, wherein the constituent phases are joined at a neutral or common connection. In an embodiment where the multi -phase winding consists of 3 phases, this arrangement would be known as a ‘Y’ or ‘star’ connection. It is envisaged that one skilled in the art would appreciate that this star connection approach could be readily extended to configurations comprising of greater than 3 phases such as 5, 6, 7 or 9 phase. It is also envisaged that embodiments could be constructed wherein the multiphase windings are connected with the neutral of the respective phase connected to the active terminal of the adjacent phase, conventionally known as a ‘delta’ winding configuration.

[0071] The stator windings 135 in an embodiment are individually packaged, preferably as modules to provide a greater level of physical insulation and separation between the wire windings 135 and the motor housing 119 and stator core 140 leading to enhanced reliability. Individually packaging each stator winding 135 also permits easier disassembly for maintenance and replacement in the event of default condition within the stator module 130, for example, in the event of disconnection of a wire or phase input, a short between a stator winding 135 and the stator structure 140 or electrical ground, a short between a stator winding 135 of one phase and the stator winding 135 of another phase, and / or a short between windings turns within the same phase. The individual stator windings units 135 in an embodiment are bolted to stator core 140 and / or housing 119. The stator windings 135 in an embodiment can be constructed and arranged around the stator core 140 as described and taught in PCT / AU2018 / 050553 (WO 2018 / 218314), the entirety of which is incorporated by reference. Other constructions, arrangements, and / or configurations are contemplated for stator module 130 and stator windings 135.

[0072] In one or more embodiments, each stator module 130 features two or more independent sets of multiphase windings. For example, within a single stator module 130, two (e.g., dual) sets of three-phase stator winding 135 are provided, where first set 134 of three-phase stator windings 135 is independent of the other second set 139 of three-phase stator windings 135. In one ormore configurations, separate independent sets of electrical connectors 115 are provided and each of electrical connectors 115 is independently connected to one set of the stator windings 135. For example, as shown in FIG. 14, top set of electrical connectors 115 is connected to first set 134 of three phase stator windings 135, and more specifically the first set 134 of stator windings 135 contains a first group of stator windings 135, e.g., first stator windings 131, electrically connected to first phase alternating-current input 127, a second group of stator windings 135, e.g., second stator windings 132, electrically connected to second phase alternating-current input 128, and a third group of stator windings 135, e.g., third stator windings 133, electrically connected to third phase of alternating current input 129. Bottom set of electrical connectors 115 in the example is connected to second set 139 of three phase stator windings 135, and more specifically first phase alternating-current input 127’ is electrically connected to respective first group of stator winding 135, e.g., windings 141, second phase alternating-current input 128’ is electrically connected to respective second group of stator winding 135. e.g., windings 143, and third phase alternating-current input 129’ is electrically connected to respective third group of stator winding 135, e.g., windings 144.

[0073] By having two separate, independent sets 134, 139 of stator windings 135 located about the circumference of the stator core 140, a single stator module 130 effectively has two stator elements, e.g., two motor elements, such that operation and rotation of the rotor assembly 150 should continue should one set of the two sets of stator windings 135 fail. That is, should power to one set of the stator windings 135 fail, or should one set of the stator windings 135 fail, the stator module 130 would still produce an electromagnetic field and force its corresponding rotor assembly 150 to rotate so that the electric motor assembly would remain operational.

[0074] In an embodiment, as shown in FIG. 14, first set 134 of multiphase stator windings 135, preferably arranged as three phase windings 131, 132, and 133 (also referred to as three phase winding band A), is configured to occupy one-half of the stator core 140. and the second set 139 of the multiphase stator windings 135, preferably arranged as three phase windings 141, 143, and 144 (also referred to as three phase winding band B), occupies the other half of the stator core 140. In the manner shown in FIG. 12(BB), the two independent sets 134, 139 of the stator windings 135 are physically and electromagnetically separate from each other except along the plane of symmetry between the two halves. The layout and arrangement of stator windings 135in sets 134, 139 as shown in FIG. 14 maximizes their physical separation while minimizing the mutual magnetic coupling between the two sets 134, 139 of 3-phase windings. In the event one set of the stator windings 135 should fail, whether for lack of power or some other fault, the other set of stator windings 135 should remain operational - an electromagnetic force will be created and applied to the rotor assembly 150 to rotate main shaft 120 and still produce torque. In another embodiment, the two sets 134, 139 of three phase stator windings 135 are interleaved in a repeating pattern around the circumference of the stator core 140. While this second embodiment does not preserve the large amount of physical and electromagnetic separation as the first embodiment, it provides continued operation of the motor module 126 without the resulting unbalanced force being exerted upon the rotor assembly 150 by the corresponding stator module 130. While the example electric motor assembly 110 is illustrated with dual, three phase stator windings, e.g., two sets of three groups of three-phase stator windings, it should be appreciated that more than two independent sets of stator windings 135, and further that single phase stator windings, two phase stator windings, or greater than three phase stator windings and input power, can be utilized.

[0075] The disclosed electric motor assembly preferably is a Fractional Slot Concentrated Winding motor where the number of slots per pole per phase (ssp) is preferably 2 / 5 or 1 / 2, or alternatively 2 / 7, 3 / 8, or 3 / 7, where an example is a motor assembly with 16 poles and 18 slots, or more preferably 16 poles and 24 slots. The poles refer to the alternating magnetic poles 161, 171 referred to above, while slots refer to the number of spaces in between stator teeth 145 where the stator windings 135 are placed. The electric motor assembly 110 has a range of sizes and in an embodiment has a working or airgap diameter, which refers to the location of air gap 149 between the stator windings 135 and the rotor assembly 150, between about 150 mm and 450 mm, with the rotor assembly 150 per motor module 126 having a working length “WL” of about 80 mm to about 200 mm. The air gap 149 between the stator 130 and the rotor assembly 150 is an amount between 1 mm and 7 mm.

[0076] In another embodiment, the electric motor assembly 110 includes multiple motor modules 126 (stator 130 and rotor 150 combinations). The modular motor assembly 110 can have a rear motor module in which the active elements (e.g., stator windings 135 and magnets 160) and structural components are largely identical to the front motor module, and each of rear motormodule and front motor module are largely identical to the motor module 126 described in connection with FIGS. 6-15. The multiple motor modules in one or more embodiments are configured to provide partial power states in the event of a fault. By way of example, the electric motor assembly 110 may have two or more motor modules, each motor module containing at least one independent stator winding 135. Providing physical isolation between the stator windings 135 contained within these stator modules in the event that a fault condition arises within first motor module, preferably isolates the effects of this fault condition to the affected first motor module, allowing the second motor module (or modules) to continue to deliver power. That is, the motor modules can operate independently of each other such that a fault contained in one motor module can be contained to that motor module and not affect the operation of the other motor module.

[0077] Typically, the number of rotor assemblies 150 is equal to the total number of independent stator modules 130, although it should be appreciated that multiple rotor assemblies 150 can be contained in a single stator module, or multiple independent stator assemblies / modules 130 could contain a single rotor assembly 150. The multiple rotor assemblies 150 are preferably mounted laterally side-by-side along the longitudinal axis of the main shaft 120. One or more bearings 125 support the main shaft 120, and in an embodiment more bearings 125 support main shaft 120 in a motor assembly 110 that contains multiple motor modules (e.g., multiple rotor assemblies 150 and / or multiple stator modules 130).

[0078] EPS 100 in one or more arrangements includes an optional cooling / lubricant system 210. FIGS. 3-5 illustrates block diagrams of example configurations of EPS 100 including example arrangements of optional cooling / lubricant system 210. Optional cooling / lubricant system 210 in an embodiment cools and lubricates electric motor assembly 110, cools motor controllers 180, and optionally cools and lubricates main gear box 190. EPS 100 further optionally includes a vent system 270. that in one or more arrangements vents the optional cooling / lubricant system 210.

[0079] EPS 100 with optional cooling / lubricant system 210, as shown in FIGS. 3-5, in an embodiment includes a reservoir or tank 215 filled with fluid 212, e.g., silicon or turbine oil, and one or more pumps 220. More or less tanks 215 and / or pumps 220 are contemplated for the EPS 100. For example, multiple tanks 215 can be used with one or more pumps 220. In a preferredconfiguration pump 220 is driven directly by main shaft 120, specifically the rear (lead) end 124 of the main shaft 120 at the rear (lead) end 114 of the electric motor assembly 110. Spline coupling 123 can be at the rear (lead) end 124 of main shaft 120 to mate with a drive shaft 222 for pump 220. Driving the pump 220 directly by the rear (lead) end 124 of main shaft 120 at the rear (lead) end 114 of electric motor assembly 110 while the front (drive) end 122 of main shaft 120 at the front (drive) end 112 of the electric motor assembly 110 drives the power train (e.g., gear box 190) which outputs the proper RPM operating range of the propulsor 107 has packaging advantages.

[0080] As illustrated in FIGS. 3-5 the cooling / lubricant system 210 includes a conduit, channel or pathway system 240 that directs fluid 212 from the reservoir or tank 215 to and through at least one of the motor controllers 180, preferably all motor controllers 180, and preferably to and through electric motor assembly 110 and returns to the reservoir or tank 215. The conduit system 240 in cooling / lubricant system 210 in one or more configurations directs fluid 212 from tank 215 to and through at least one of the motor controllers 180, preferably all motor controllers 180. preferably to and through the electric motor assembly 110, and preferably to and through the gearbox 190. The conduit system 240 is used generically to refer to the one or more lines, tubes, and / or pipes 242 connecting to and used to transfer and / or transport the coolant / lubricant fluid 212 between various components in the cooling / lubricant system 210.

[0081] One or more pumps 220 may be distributed throughout the conduit system 240. Cooling system 210, in an embodiment, includes one or more heat exchangers 230, which in one or more arrangements are associated with the aircraft 105. In one or more embodiments, the one or more pumps 220 are mechanically driven by the rear (lead) end 124 of the main shaft 120 of electric motor assembly 110, and not with or by an accessory gearbox separate from or integrated with the electric motor assembly 110, and in an aspect directly powered by the main shaft 120 of the electric motor assembly 110. With EPS 100 and electric motor assembly 110 in the embodiment of FIGS.3-5 operating at its operating speed range (5000-7000 RPM), fluid 212, e.g., oil 212, flows at rates of between 20-70 litres per minute (LPM). In an embodiment of EPS 100 where the cooling / lubricating system 210 is configured so that cooling / lubrication of the electric motor assembly 110 is in parallel and not in series with the one or more motor controllers 180, the flow rate of coolant / lubricant 212 with the electric motor assembly 110 operating at its operatingspeed range (e.g., 5000-7000 rpm) is higher, for example in a range of 70-130 LPM. Tn an embodiment, as shown in FIGS. 3-5 where the pump 220 is direct driven by main shaft 120 of electric motor assembly 110, the flow rate of coolant fluid 212 varies with the speed of main shaft 120 and the flow rate reduces at lower speeds of main shaft 120. It can be appreciated that in embodiments, the pump 220 can be driven through a gearbox coupled to the main shaft 120 of the electric motor assembly 110.

[0082] The coolant / lubricating fluid 212 in the configuration of EPS 100 of FIGS. 1, 3-5, and 16-27 flows from tank 215 through conduit system 240, e.g., conduits 242, to pump 220 and from pump 220 through conduit system 240, e.g., conduits 242, to and through filter 225. The tank 215 can include and / or incorporate a coolant level sensor 234 to determine the amount of coolant / lubricant fluid 212 in the cooling system 210. Cooling system 210, and in an embodiment tank 215, can include a chip detector 216 to detect whether any wear is occurring in the EPS 100. In an embodiment, chip detector 216 has a small pair of magnetic terminals designed to produce an alert when the terminals are bridged by chips of magnetic material, indicating particles and / or chips in the coolant / lubricant 212, which indicates that the bearings, gears, splines, or other moving parts are wearing. Cooling system 210 also preferably includes a pressure sensor 232 for measuring pressure in the cooling system 210 including within conduit system 240 and / or other components and assemblies (e.g., heat exchanger 230, bypass 243, electric motor assembly coolant / lubricant inlets 116). Cooling system 210 in one or more configurations further includes a pressure switch 233, preferably associated with filter 225, to evaluate whether the filter 225 has reached its maximum contaminants holding capabilities. The tank 215, pump 220. filter 225, and associated conduit system 240 for directing the flow of fluid 212 in cooling system 210 of FIGS. 23-25 is preferably easily removeable from the electric motor assembly 110 as a standalone unit, for example by undoing five connection points so a subassembly is removed from electric motor assembly 110 as a standalone unit (e.g., a line replacement unit (LRU)). In an embodiment, tank 215 is a deep drawn tank.

[0083] FIGS. 26-27 illustrate another embodiment of cooling system, e.g., cooling system 210’, that is integral to the rear (lead) end 114 (e.g., rear plate 113) of electric motor assembly 110. The integrated system of FIGS. 26-27 illustrate tank 215, pump 220 and a portion of conduit system 240 interconnecting the tank 215 and pump 220 within an extra housing 102 with filter225 mounted outside extra housing 102. Cooling subassembly of FIGS. 26-27 is more robust to vibration and more elegant in terms of integration than the cooling subassembly of FIGS.23-25.In an alternative embodiment, tank 215 for coolant 212 in coolant / lubricating system 210 can be remotely mounted, e.g., not mounted on electric motor assembly 110.

[0084] The coolant / lubricating fluid 212 flows from filter 225 to a fitting 244, e.g., manifold 245, where fluid flow is split in at least two different pathways. In a first pathway 246, fluid 212 flows through conduit system 240, e.g., conduits 242, from manifold 245 to moveable fitting 236, e.g., a moveable valve 236, to direct the coolant fluid 236 to flow to and through heat exchanger 230 or through bypass 243 to flow around (e.g., not through) and not use heat exchanger 243. A thermostat in an embodiment is placed and / or configured in cooling system 210 to determine whether to have coolant fluid 212 flow through heat exchanger 230 or through bypass 243.

[0085] In the coolant / lubrication system 210 of FIG.3, coolant fluid 212 in first pathway 246 of cooling system 210 flows from heat exchanger 230 or bypass 243 through fitting 244 and through conduit system 210 to input 3-way manifold 241, e.g., a splitter, where the flow of the coolant fluid 212 is split into a first MC pathway 252 to flow into inlet 181 of first motor controller 180 and a second MC pathway 254 to flow into inlet 181’ of second motor controller 180’. That is, the first MC pathway 252 is independent from and parallel to second MC pathway 254. First MC pathway 252 from first motor controller 180 communicates with output 3-way manifold 247, e.g., combiner 247, and second MC pathway 254 from second motor controller 180’ also communicates with output 3-way manifold 247 where at output 3-way manifold 247 the two separate fluid pathways 252, 254 are combined to form a single fluid pathway after the motor controllers 180, 180’ in conduit system 210 that delivers the coolant / lubricating fluid 212 to the one or more coolant inlets 116, e.g., EMA inlet(s) 250, of the electric motor assembly 110.The coolant fluid 212 flows through the electric motor assembly 110 and exits coolant outlet 118, e.g., EMA outlet(s) 251, where coolant fluid 212 flows through conduit system 240, more specifically conduit tube 242, to tank 215. In FIGS. 3-5, character 244 is used to refer to a fitting, manifold, and / or splitter in conduit system 240.

[0086] In one or more embodiments, as illustrated in FIG.3, conduit system 240 extends between the one or more motor controllers 180 and the electric motor assembly 110 so the samefluid 212 flows through both the electric motor assembly 110 and the motor controllers 180. That is, fluid 212 that flows through at least one of the motor controllers 180 then proceeds to flow through the electric motor assembly 110. The conduit system 240 can include one or more splitters or manifolds 236, 241, 244, 245, 247 for separating the conduit system 240 and rejoining the conduit system 240 as shown in FIGS. 3-5. In alternative embodiments, cooling / lubricating system 210 for the electric motor assembly 110 can be arranged to be in parallel with the one or more motor controllers 180. That is, while the same fluid 212 is used in the coolant / lubrication system 210, fluid 212 flows through the one or more motor controllers 180 simultaneous with and in parallel to the fluid 212 that flows through the electric motor assembly 110. It is contemplated a higher fluid flow rate would be required for a coolant / lubricant system 210 that is arranged so that the electric motor assembly cooling is in parallel with the motor controller cooling.

[0087] The electric motor assembly 110 can include coolant inlets 116, e.g., EMA cooling inlets 249, connected to stator cooling (e.g., longitudinal) channels 142 to direct the coolant fluid 212 to flow through the stator windings 135 in the electric motor assembly 110. That is, the coolant fluid 212, preferably liquid coolant 212, enters electric motor assembly 110 and at least in part Hows through longitudinal channels 142 formed in the stator module 130 of the electric motor assembly 110, and in an arrangement the coolant fluid 212 flows in contact with the stator windings 135 to cool the stator windings 135 as the coolant fluid 212 flows down multiple longitudinal cooling channels 142 (see FIG. 15) arranged parallel to the main shaft 120 of the electric motor assembly 110. Coolant 212 exits electric motor assembly 110 at cooling outlet 118, e.g., EMA cooling outlet 250, and flows through conduit system 240 to tank 215.

[0088] Each coolant inlet 116 (249), coolant outlet 118 (250), and connecting cooling channels 142 inside electric motor assembly 110, e.g., the longitudinal cooling channel 142 through the stator windings 135 and configured to direct the coolant fluid 212 in direct contact with the stator windings 135, can form independent cooling paths through the electric motor assembly 110. In an embodiment, end chambers, e.g., annular end chambers, can be formed at the liquid coolant inlet 116 and liquid coolant outlet 118 that connect with the longitudinal cooling channels 142 formed through the stator windings 135 such that liquid coolant 212 flows through coolant inlet 116 into an inlet end chamber and from inlet end chamber through the one or more (independent)longitudinal cooling channels 142 formed through the stator windings 135, from the one or more longitudinal cooling channels 142 into the outlet end chamber and then through the liquid coolant outlet 118. In one or more embodiments the one or more coolant inlets 116, stator cooling channels 142, and one or more coolant outlets 118 are configured as described and taught in PCT / AU2018 / 050553 (WO 2018 / 218314), the entirety of which is incorporated by reference. In an alternate embodiment, multiple coolant inlets 116 and coolant outlets 118 can connect and communicate with a common channel though the electric motor assembly 110.

[0089] Each motor controller 180 preferably also includes one or more inlets 181 to an internal cooling channel to direct fluid 212 to flow into and through the housing 185 of the motor controller 180 to cool the circuits and components inside the motor controller housing 185, particularly the high-voltage, high-power circuits. Preferably the cooling channel inside the motor controller 180 is formed with no seals so that the fluid 212 cannot leak into the compartment of the motor controller 180 where the circuitry is contained as described and taught in U.S. Patent Application Serial No. 16 / 888,809 filed on May 31, 2020, the entirety of which is incorporated by reference. Internal cooling channel in housing 185 of motor controller 180 is in communication with outlet 183 of motor controller 180 so that coolant fluid 212 entering inlet 181 of the motor controller 180 exits the motor controller 180 at outlet 183. In an alternative embodiment, multiple independent cooling systems 210 can also be included so that a cooling system 210 used for one or more electric motor assemblies 110 is separate from the cooling system 210’ used for the motor controllers 180, and in a further embodiment each electric motor assembly 110 can have a separate cooling system 210, and each motor controller 180 can have a separate cooling system 210’.

[0090] Various communications, sensors, and feedback systems that can be employed in the EPS 100, and / or between the aircraft 105 and the EPS 100. For example, temperature sensors 235 can be included in one or more of the motor controllers 180 and / or electric motor(s) 110.Temperature data from the temperature sensors 235 is communicated via one or more lines between the motor controllers 180 and / or the electric motor assemblies 110, and in an aspect temperature data from the electric motor assembly 110 can be communicated via input to the one or more motor controllers 180. Temperature data in an aspect is communicated from the electric motor assembly 110 separately to each motor controller 180. The temperature data can beprocessed by the motor controller 180, optional system controller and / or other interface to provide information and alerts to the aircraft displays and crew notification interfaces on the operating state and health of the components of EPS 100. In an example embodiment, temperature data can be used to direct the flow of coolant fluid 212 in optional cooling system 210, for example by varying the flow rate of the coolant fluid 212 and / or directing coolant 212 to flow through heat exchanger 230 or use bypass 243.

[0091] In addition, in an embodiment cooling system 210 can include one or more pressure sensors 232 (and / or a temperature sensor 235) in one or more of the cooling system conduits 242, pump 220, tank 215, one or more of motor controllers 180 e.g., (in communication with the cooling system 210 and / or conduit system 240), and / or the one or more electric motor assemblies 110 (e.g., in communication with the cooling system 210 in the electric motor assembly 110) that communicates pressure data (and / or temperature data) to the EPS 100, the one or more motor controllers 180, a system controller, and / or other interface via a communication and data line.

[0092] In one or more embodiments, the same coolant fluid 212 that is used to cool the electric motor assembly 110 and the one or more motor controllers 180 is further optionally used as lubricant fed into the electric motor assembly 110 to lubricate one or more moving parts in the electric motor assembly 110 (e.g., the electric motor assembly bearings 125). For example, as shown in FIG. 3, fluid 212, after filter 215 via manifold / splitter 245, also flows into second pathway 248 to electric motor assembly 110 forming a pressurized fluid pathway to lubricate bearings 125 and / or spline couplings 121, 123. More specifically, as shown in FIG. 3, second pathway 248 feeds fluid 212 to drive oil inlet 253 via drive conduit 251 and to lead oil inlet 256 via lead conduit 255. Fluid 212 delivered to drive oil inlet 253 lubricates drive end bearings 196 and exits electric motor assembly 110 at drive oil outlet 257 while fluid 212 delivered to lead end oil inlet 256 lubricates lead end bearing 198 and (and lead end coupling 123) and exits electric motor assembly 110 at lead oil outlet 258.

[0093] A pressurized fluid conduit communicates with a nozzle, e.g., a jet nozzle 170, to spray lubricant 212, which is the same fluid as coolant 212, on bearings 125 and / or spline couplings 121, 123 in electric motor assembly 110. Pressurized fluid conduit and nozzle, e.g., jet nozzle 170, can be configured for each bearing 125, e.g., drive end bearing 196 and lead end bearing 198, in electric motor assembly 110. Dynamic seals 178 can be provided with grease packed ballbearings 125 to retain lubricant 212. An eductor can be added and / or used with bearings 125 to scavenge the bearing cavities if desirable. Pressurized fluid conduit(s) 169 can have separate inlets, e.g., drive oil inlet 253 and lead oil inlet 256, into the housing 119 of the electric motor assembly 110 and / or have separate outlets, e.g., drive oil outlet 257 and lead oil outlet 258, or use the coolant inlets 116 and coolant outlets 118 used for cooling the stator windings 135.

[0094] Referring to FIGS. 16-19, the flow of fluid 212 through the electric motor assembly 110 from drive oil inlet 253 to drive oil outlet 257 to lubricate and cool drive end bearing 196 is shown and described in more detail. Fluid 212 as shown by the arrows in FIGS. 17-19 enters pressurized fluid conduit at drive oil inlet 253 and flows through a nozzle or injector 260 that sprays and / or injects fluid 212 into the drive end bearing 196 so fluid 212 flows through drive end bearing 196 and drains out drive oil outlet 257. Nozzle 260 and / or pressurized pathway can include a screen 262 and / or a restrictor 264 before entering the pathway to deliver fluid 212 to drive end bearing 196.

[0095] Referring to FIGS. 20-22, the flow of fluid 212 through the electric motor assembly 110 from lead oil inlet 256 to lead oil outlet 258 to lubricate and cool lead end bearing 198 is shown and described in more detail. Fluid 212 as shown by the arrows in FIGS. 20-22 enters pressurized fluid conduit at lead oil inlet 256 and flows through a nozzle or injector 260 that sprays and / or injects fluid 212 into the lead end bearing 198 so fluid 212 flows through lead end bearing 198 and drains out lead oil outlet 258. Nozzle 260 and / or pressurized pathway can include a screen 262 and / or a restrictor 264 before entering the pathway to deliver fluid 212 to lead end bearing 198.

[0096] The flow of fluid 212 through lead oil inlet 256 to lead oil outlet 258 can also be configured and arranged to lubricate and cool one or more spline couplings, e.g., lead spline coupling 123. In an embodiment, as shown in FIGS. 22 and 24, optional cooling / lubricant system 210, and in particular the conduit system 240 from lead oil inlet 256 to lead outlet 258 can include an optional spline conduit 265 that directs fluid 212 as shown by the arrows to spline coupling, e.g., spline coupling 123. and drains fluid 212 (after lubricating and cooling the spline coupling, to lead oil outlet 258. That is, in an arrangement, as shown in FIGS. 22-24, the lubricating of the spline coupling 123 uses a separate spline lubricating / cooling circuit 265 from the bearing circuit 266, e.g.. bearing lubricating / cooling conduit 266, that lubricates and / or coolsthe bearings, e.g., lead end bearing 198. Spline lubricating / cooling circuit 265 is shown as being in parallel to the bearing lubricating / cooling circuit 266 but it can be appreciated that the spline lubricating / cooling circuit 265 can be in series with bearing lubricating / cooling circuit 266. It further can be appreciated that a spline lubricating / cooling circuit, for example similar to spline lubricating / cooling circuit 266, can be incorporated to lubricate and / or cool the drive end spline coupling 121.

[0097] In one or more arrangements, lubricant / cooling system 210 includes a pressure relief valve 228. For example, after and / or at manifold 245 that splits conduit system 240 into first pathway 246 and second pathway 248, conduit system 240 as shown in FIG. 3 can further include third pathway 268 (after filter 225) that directs fluid 212 back to tank 215. Third pathway 268 includes a pressure relief valve 228. Pressure relief valve 228 can be located at different locations in the EPS 100 of FIG. 3, for example at and / or after the outlet of heat exchanger 230, e.g., at and / or after fitting 244 illustrated in FIG. 3. Additionally, and / or alternatively, multiple pressure relief valves 228 can be incorporated in conduit system 240, for example in third pathway 268 as illustrated and at the outlet of the heat exchanger 230 (e.g., where bypass 243 and output of heat exchanger 230 meet). Tank 215, conduit system 240, and / or lubricating and / or cooling system 210 of FIG. 3 in one or more arrangements includes a vent system 270 that includes vents 271.

[0098] Another embodiment of lubricating / cooling system 210 is shown in FIG. 4. Lubricating and / or cooling system 210 incorporated in the embodiment of EPS 100 in FIG. 4 is similar to lubricating / cooling system 210 of the embodiment of EPS 100 in FIG. 3. Lubricating / cooling system of EPS 100 of FIG. 4 includes fluid 212 that circulates in parallel through one or more motor controllers 180 and then in series through electric motor assembly 110. Lubricating and / or cooling system 210 of the EPS 100 of FIG. 4 includes a pump 220 that receives fluid 212 from tank 215 and supplies fluid 212 to filter 225. From filter 225 fluid 212 can flow in third pathway 268 to pressure relief valve 228 and back to the tank 215.

[0100] Pressure relief valve 228 can be located at different and / or multiple locations in conduit system 240 of EPS 100 of FIG. 4. For example, as shown in cooling / lubricating system 210 of EPS 100 of FIG. 5, third pathway 268 containing relief valve 228 can be positioned after heat exchanger 230 and before the motor controllers 180, e.g., at and / or off of manifold 241. Thisnew third pathway 268’ with relief valve 268 leads back to tank 215. This new third pathway 268’ (illustrated in FIG. 5) can be in addition to and / or alternative to third pathway 268 shown in FIG. 4.

[0101] From filter 225 in the EPS 100 of FIG. 4, fluid 212 can also flow to manifold 245 where it can further flow in first pathway 246 to heat exchanger 230 or through bypass 243 to and through the motor controllers 180, and to and through the electric motor assembly 110 and return to tank 215. More specifically, fluid 212 flows through first pathway or circuit 246 into electric motor assembly cooling inlet 116, e.g., EMA cooling inlet 249, through the stator 130 and / or stator windings 135, e.g., as explained in connection with the lubricating / cooling system 210 of the EPS 100 of FIG. 3, and out electric motor assembly cooling outlet 118, e.g., EMA cooling outlet 250. Conduit system 240 in the EPS 100 of FIG. 4 can include a motor inlet screen 275 upstream of the cooling inlet 116, e.g., EMA cooling inlet 249, of the electric motor assembly 110, including between the motor controllers 180 and the EMA cooling inlet 249 of the electric motor assembly 110.

[0102] From manifold 245 in EPS 100 of FIG. 4, fluid 212 can also flow into two separate pressurized fluid pathways. Fluid 212 from manifold 245 in EPS 100 of FIG. 4 can flow into drive conduit or pathway 251 where fluid 212 is supplied to drive oil inlet 253 to travel to, lubricate and / or cool drive end bearings 196 and / or drive end spline / spline coupling 121. After cooling and / or lubricating drive bearing 196 and / or drive spline / spline 121, fluid 212 exits electric motor assembly 110 through drive oil outlet 257 from which fluid 212 flows to tank 215. Fluid 212 from manifold 245 in EPS 100 of FIG. 4 can also flow into lead conduit 255 where fluid 212 is supplied to lead oil inlet 256 to travel to, lubricate and / or cool lead end bearings 198 and / or lead end spline / spline coupling 123. After cooling and / or lubricating lead bearing 198 and / or lead spline / spline coupling 123, fluid 212 exits electric motor assembly 110 through lead oil outlet 258 from which fluid 212 flows to tank 215. Either one of lubricating / cooling systems and pathways (conduit systems) illustrated and described in connection with FIGS. 16-22 can be used to lubricate and cool drive end bearing 196, drive spline / spline coupling 121, lead end bearing 198, and / or spline / spline coupling 123.

[0103] EPS 100 and / or optional lubricating / cooling system 210 of the EPS 100 of FIG. 4 further includes a vent system 170 having one or more vents 171. Vent system 170 in the embodiment ofEPS 100 of FIG. 4 includes a drive side bearing vent conduit 272 that communicates with tank 215 to vent the drive end bearing 196 and a lead end bearing vent conduit 274 that communicates with tank 215 to vent lead end bearing 198.

[0104] Another embodiment of lubricating / cooling system 210 is shown in FIG. 5. Lubricating and / or cooling system 210 incorporated in the embodiment of EPS 100 of FIG. 5 is similar to lubricating / cooling system 210 of the embodiment of EPS 100 in FIG. 4. In the lubricating and / or cooling system 210 of the EPS 100 of FIG. 5, the same coolant fluid 212 that is used to cool the electric motor assembly 110 and the one or more motor controllers 180 is further optionally used as a lubricant in a drive train (e.g., a (reduction) gearbox 190) driven by the main shaft 120 of the electric motor assembly 110, preferably the front (drive) end 122 of main shaft 120, preferably through a spline coupling 121 at the front (drive) end 122 of main shaft 120. Lubricating / cooling system of EPS 100 of FIG. 5 includes fluid 212 that circulates in parallel through one or more motor controllers 180 and then in series through electric motor assembly 110. The lubricating / cooling system 210 of EPS 100 of FIG. 5 further includes electric motor assembly lubricating conduit systems or circuits 251 and 255 to lubricate and / or cool the splines / spline couplings 121, 123 and / or the bearings 125, e.g., drive end bearings 196 and lead end bearings 198. Lubricating and / or cooling system 210 of EPS 100 in FIG. 5 further includes an optional gearbox lubricating / cooling system 280 to lubricate and / or cool gearbox 190 (e.g., driven by main shaft 120 of electric motor assembly 110).

[0105] In one or more arrangements, gearbox lubricating / cooling system 280 is a separate gearbox conduit system 282 that uses the same fluid 212 of lubricant / cooling system 240. After heat exchanger 230 fluid 212 splits so a portion of fluid 212 flows in gearbox lubricating / cooling system 180, more particularly in gearbox cooling conduit 282 to and through gearbox 190, and a portion of fluid 212 that flows through heat exchanger 230 continues to flow to and through motor controllers 180 and / or electric motor assembly 110, e.g., to and through manifold 241. Gearbox cooling conduit 282 in gearbox cooling system 280 directs fluid 212 to flow to and through gearbox 190, e.g., to cool and / or lubricate gearbox 190, and takes fluid 212 back to tank 215. Fluid 212 delivered to gearbox 190 can be used to cool and / or lubricates the gears, e.g., the gear train, the bearings, and / or the couplings, e.g., spline couplings, in gearbox 190. The fluid 212 delivered to the gearbox 190 can utilize one or more of the nozzles and / or injectors 260described in connection with the lubricating and cooling of the spline / spline couplings 121, 123 and / or bearings 125, e.g., drive end bearings 196 and / or lead end bearings 198.

[0106] While gearbox cooling / lubricating system 280 and gearbox cooling conduit 282 is shown in EPS 100 of FIG. 5 as received fluid 212 after heat exchanger 230, it can be appreciated that a portion of fluid 212 that flows in bypass 243 can be directed to flow through gearbox cooling system 280 to cool / lubricate gearbox 190, while another portion of fluid 212 in bypass 243 flows to manifold . In addition, and / or alternatively, while gearbox cooling system 280 can be a separate circuit from, and parallel to the cooling / lubricating system of the motor controllers 180 and electric motor assembly 110, including separate from first (cooling) pathway / circuit 246, second pathway / circuit 248, drive conduit circuit 251, and lead conduit circuit 255, it can be appreciated that gearbox cooling system 280 and gearbox cooling conduit 282 can be in series in any one of first (cooling) pathway / circuit 246, second pathway / circuit 248, drive conduit circuit 251, and lead conduit circuit 255. For example, gearbox cooling system 280 and gearbox cooling conduit 282 in the EPS 100 can be in series in front of, e.g., before, the motor controllers 180, in series after the motor controllers 180 and before the electric motor assembly 110, and after the electric motor assembly 110, e.g., after EMA cooling outlet 250.

[0107] Alternatively, gearbox cooling system 280 and gearbox cooling conduit 282 can be in series in second pathway / circuit 249 before second pathway / circuit 249 splits into drive conduit circuit 251 and lead conduit circuit 255, or after drive oil outlet 257 and / or lead oil outlet 258. Alternatively, gearbox cooling system 280 and gearbox cooling conduit 282 can be in series in front of one or both of the electric motor assembly 110 in drive conduit circuit 251, e.g., before drive oil inlet 253, and / or before the electric motor assembly 110 in lead conduit circuit 255, e.g., before lead oil inlet 256, and / or in series after the electric motor assembly 110 in one or both of drive conduit circuit 251, e.g., after drive oil outlet 257, and lead conduit circuit 255, e.g. after lead oil outlet 258. The configuration of gearbox cooling system 280 and gearbox conduit 282 can depending upon cooling requirements and packaging.

[0108] The cooling / lubrication system 210 of EPS 100 of FIG. 5 further includes a relief valve 228. In EPS 100 of FIG. 5, a third pathway 268 starts at manifold 241 (located after heat exchanger 230 and before the motor controllers 180) and directs fluid 212 through relief valve 228 and into tank 215. While relief valve 228 in EPS 100 of FIG. 5 is positioned differently thanin the EPS 100 of FIGS.3-4, it can be appreciated that positioning of relief valve 228 in EPS 100 of FIG. 5 can be in addition to or alternatively to positioning of relief valve 228 in EPS 100 of FIGS.3-4. In one or more embodiments, the electric motor 110 also communicates with the motor controllers 180 via communication lines, preferably electric motor assembly 110 communicates to each motor controller 180 via communication lines. In one or more embodiments, the electric motor assembly 110 can communicate main shaft 120 revolutions per minute (RPM), the angular position of the main shaft 120 through an angular position sensor such as a variable reluctance resolver, optical encoder, or a set of hall-effect sensors, and / or other data to the motor controllers 180 via communication and data lines, preferably separately to each motor controller 180. The motor controllers 180 in an aspect process and monitors the data from the electric motor assembly 110 to determine whether to adjust the speed and / or torque of the electric motor 110. The one or more motor controllers 180 in an embodiment communicate with each other and exchange data via a communication line, and optionally also include a discrete input / output line between the two motor controllers 180. The discrete inputs and outputs use high and low voltage states as a direct communication mechanism for important system states. For example, a discrete input can be pulled high to indicate the aircraft is ready for the motor controller 180 to apply power to the electric motor assembly 110, or to indicate that an aircraft 105 or EPS 100 fault state that requires the motor controller 180 to immediately shut down. Discrete outputs from the motor controller 180 in an example are typically used to indicate that the system requires HVDC voltage to be removed or opened (via switches located in the PDU) due to an error or fault detected by the motor controller 180. By having two motor controllers 180 communicate with each other, data and feedback from sensors within the EPS 100 can be checked. In addition, having two motor controllers 180 provides a redundancy where if one motor controller 180 fails, the EPS 100 can remain operational.

[0109] An optional system controller can be included in the EPS 100. the system controller according to one or more aspects can communicate with the one or more motor controllers 180 via a communication and data line, and preferably communicates to each motor control 180 separately via the communication and data line. The system controller, one or more of motor controllers 180, and / or other interface in an embodiment also sends control signals to the cooling system tank 192 and / or pump 194 to control and regulate the temperature and / or pressure in thecooling system 190. The system controller in an embodiment receives from the motor controllers 180, preferably independently via a communication line from each motor controller 180, discrete output. The discrete output received is in the form of a high / low signal indicating the operating state of the motor controller 180. In an aspect, the aircraft interface and system controller communicate with each other via a communication and data line. It can be appreciated that the functions and operations of the system controller can be incorporated into the one or more motor controllers 180. The aircraft interface provides control information to control and regulate the EPS 100. The system controller can also have a discrete output that communicates to the aircraft interface via another communication and data line. In an embodiment, the power management system and / or PDU can communicate with the aircraft interface, and in a further aspect, the aircraft interface can communicate and control the PDU.

[0110] The aircraft interface provides control information to control and regulate the EPS 100. The motor controller(s) 180 receives from the aircraft interface throttle control input which communicates how must torque to create by the electric motor assembly 110. The throttle control input in an aspect is analogue data. The motor controller 180 receives the throttle control input, processes the throttle control input, and provides or varies the HVAC output 184 to the electric motor assembly 110 to vary the torque provided by main shaft 120 of electric motor assembly 110.

[0111] A system to convert electrical power to torque is disclosed where in one or more embodiments the system includes: one or more motor controllers, each motor controller adapted and configured to receive power input commands and to receive high-voltage, direct-current (HVDC) input power and convert the HVDC input power to multiphase high-voltage, alternating-current (HVAC) output power, wherein each motor controller varies its respective multiphase HVAC output power in response to the power input commands received; and an electric motor assembly having a main shaft for supplying torque, the electric motor configured and adapted to receive input power as multiphase HVAC from the one or more motor controllers to rotate the main shaft. The electric motor assembly in an embodiment includes: one or more stator modules, each stator module having a plurality of stator windings configured to receive HVAC power from the one or more motor controllers; one or more rotor assemblies, each rotor assembly having a plurality of magnets arranged around the outer periphery of a hub, wherein atleast one of the one or more rotor assemblies is configured to rotate the main shaft, and at least one or more of the rotor assemblies is associated with, preferably concentrically contained within, and rotatable relative to one of the one or more stator modules.

[0112] In one or more configurations, each motor controller is configured to receive power input commands and to receive high-voltage, direct-current (HVDC) input power of between 400-850 DC volts and convert the HVDC input power to multiphase high-voltage, alternating-current (HVAC) output power at a fundamental frequency of about 10 hertz to about 1000 hertz, wherein each motor controller varies its respective multiphase HVAC output power in response to the power input commands received. Each stator module preferably has a plurality of stator windings and a stator core having a plurality of spaced apart projecting structures forming between 20 to 30 slots, preferably 24 slots, where each projecting structure has one of the plurality of stator windings wrapped about the projecting structure and configured to receive the HVAC power from the one or more motor controllers. Each rotor assembly preferably has a plurality of magnets arranged around an outer periphery of a hub to form between 14 to 18 magnetic poles, preferably 16 magnetic poles, and in an embodiment each magnetic pole comprises at least three magnets with their magnetic poles oriented in different directions. In a configuration the electric motor assembly comprises at least two sets of three electrical connectors to receive HVAC from the one or more motor controllers. The hub of at least one rotor assembly in an arrangement has one or more twisted blades to assist with axially moving air through the electric motor assembly and / or one or more radial vanes to move air radially on to the rotor to facilitate cooling the electric motor assembly.

[0113] In an embodiment, the one or more motor controllers in combination generate between 160 kW and 500 kW of HVAC output power, where preferably each motor controller generates between 80 kW and 250 kW of HVAC output power. In a further embodiment, each motor controller outputs about 10 volts RMS to about 850 Volts RMS. more preferably about 10 volts RMS to about 560 Volts RMS and about zero to about 700 amps RMS, more preferably about 10 to 500 amps RMS. at the frequency range of about 10 Hertz to about 1000 Hertz.

[0114] The system can further contain a cooling system preferably having a liquid coolant, wherein the liquid coolant is configured to flow through both the electric motor assembly and at least one of the motor controllers. In an aspect, each of the one or more motor controllers has ahousing, wherein the liquid coolant flows through the housing of at least one of the motor controllers. The system in an embodiment includes at least two motor controllers and the system is configured so that the liquid coolant flows through at least two of the housings of the motor controllers in parallel and through the electric motor assembly in series with the at least two motor controllers. The liquid coolant flows through and in contact with at least one of a group of the plurality of stator windings. The liquid coolant in an embodiment includes turbine oil. although other fluids and oils are contemplated.

[0115] In one or more configurations, the liquid coolant flows through a first pathway through the at least one of the motor controllers and through at least one of the plurality of stator windings in the electric motor assembly and the liquid coolant flows through a second pathway in the electric motor assembly through at least one of a lubrication group consisting of: a bearing, a spline, a shaft coupling, and combinations thereof to lubricate the at least one of the lubrication group. The second pathway in an embodiment is pressurized. The first pathway through the electric motor assembly according to an approach is parallel to the second pathway through the electric motor assembly. The second pathway in an embodiment includes a drive end channel to lubricate at least one of a drive end lubrication group consisting of: a drive end bearing, a drive end spline, a drive end shaft coupling, and combinations thereof to lubricate the at least one of the drive end lubrication group and a lead end channel to lubricate at least one of a lead end lubrication group consisting of: a lead end bearing, a lead end spline, a lead end shaft coupling, and combinations thereof to lubricate the at least one of the lead end lubrication group. In an arrangement, the second pathway includes a spline conduit configured to deliver coolant fluid to a shaft coupling in the electric motor assembly and a separate bearing conduit configured to deliver coolant fluid to a bearing in the electric motor assembly. Optionally, the cooling system comprises one or more vents.

[0116] The liquid cooling system in an aspect contains one or more temperature sensors and data from the temperature sensors is communicated to one or more of the motor controllers for processing, and additionally or alternatively contains one or more pressure sensors and data from the pressure sensors is communicated to one or more of the motor controllers for processing. The cooling system in an embodiment further contains a reservoir or tank to contain the liquid coolant, a conduit system to channel the liquid coolant at least between the one or more motorcontrollers and the electric motor, and at least one pump to pump the liquid coolant. In an aspect, a first end of the main shaft is connectable to a drive train that drives a propulsor of an aircraft and a second end of the main shaft directly drives a pump to circulate the liquid coolant in the cooling system. The cooling system according to an embodiment circulates 25-70 liters per minute (LPM) of oil as the liquid coolant, and in a further arrangement 30-40 LPM. The electric motor assembly in an approach is configured to receive fluid as a lubricant to lubricate one or more moving parts within the electric motor assembly, wherein the same fluid used as lubricant in the electric motor assembly is used as coolant in the cooling system. In an embodiment, the electric motor assembly further comprises a jet nozzle to spray the lubricant to lubricate one or more bearings that are configured to support the main shaft, wherein the jet nozzle receives the lubricant under pressure.

[0117] The one or more motor controllers preferably are configured to produce and supply two independent multi-phases of HVAC output power, preferably three-phase HVAC, and each stator module in the electric motor is configured to receive at least two independent multiphases of HVAC output power from the one or more motor controllers. In an embodiment, a single motor controller having a single housing with a single cooling channel to receive liquid coolant in an aspect produces and supplies the two independent multi-phases of HVAC output power, wherein the single motor controller contains two independent circuits, each to produce one of the independent multiphase HVAC outputs.

[0118] In an embodiment, the plurality of stator windings on at least one of the one or more stator modules are arranged as at least two independent sets of a plurality of stator windings, each independent set of a plurality of windings is electrically isolated from the other set of a plurality of stator windings. In an approach a first independent set of a plurality of windings is spaced and separated from a second independent set of plurality of stator windings to resist magnetic coupling between sets of stator windings. In a further approach the first set of independent stator windings includes at least two groups of a plurality of stator windings, each of the plurality of stator windings in each group is electrically connected together and electrically isolated from the plurality of windings in the other groups. In a configuration, there are two independent sets of a plurality of windings in at least one of the one or more stator modules, wherein each independent set of stator windings has three groups of a plurality of statorwindings, each of the plurality of stator windings in each group of each independent set of stator windings is electrically connected together and electrically isolated from each of the plurality of windings in each other group of stator windings.

[0119] The electric motor assembly according to an arrangement is configured to receive two independent supplies of three phase, high voltage, alternating current, and wherein the first independent supply of three phase, high voltage, alternating current is configured to supply the first independent set of three groups of a plurality of stator windings, each of the three groups of stator windings in the first set configured to receive a different phase of the first independent supply of three phase, high voltage, alternating current, and wherein the second independent supply of three phase, high voltage, alternating current is configured to supply the second independent set of three groups of a plurality of stator windings, each of the three groups of stator windings in the second set configured to receive a different phase of the second independent supply of three-phase, high-voltage, alternating current. In a further embodiment, the first independent set of a plurality of windings is positioned on a first half of the at least one of the one or more stator modules and the second independent set of a plurality of stator windings is positioned on the second half of the at least one of the one or more stator modules wherein the first half is spaced from and separated from the second half to resist magnetic coupling between the first and second independent sets of stator windings.

[0120] The electric motor assembly in an embodiment is configured to receive fluid as a lubricant to lubricate one or more moving parts within the electric motor assembly, wherein the same fluid used as lubricant in the electric motor assembly is used as coolant in the cooling system. The system optionally further includes a drive train (e.g., a gearbox assembly) that derives power from the electric motor assembly, wherein the drive train is configured to receive fluid as a lubricant to lubricate one or more moving parts within the drive train, wherein the same fluid used as a lubricant in the drive train is used as coolant in the cooling system. In an aspect, the same fluid used as a lubricant in the electric motor assembly and the drive train is used as coolant for the cooling system and is taken from a common reservoir. The system optionally includes a pump that derives power from the electric motor assembly, wherein the electric motor assembly is configured to directly power the pump.

[0121] The system in one or more embodiments is configured as a propulsion system, wherein the shaft of the electric motor assembly is configured to supply torque to a propulsor of an aircraft. The system optionally further includes a drive train that receives torque from the main shaft and outputs torque at a drive shaft at lower RPM than the input RPM of the main shaft to drive the propulsor element of the aircraft at appropriate RPM. In an aspect, the drive train is configured to receive lubricant fluid to lubricate one or more moving parts within the drive train, and wherein the electric motor is configured to receive the lubricant to lubricate one or more moving parts within the electric motor assembly, and the lubricant fluid used for the electric motor assembly and / or the drive train and the liquid coolant are all the same fluid taken from a common reservoir.

[0122] The EPS in an arrangement, further includes a gearbox that receives rotational power from the electric motor assembly and drives a propulsor of an aircraft, wherein the gearbox is configured to receive fluid as a lubricant to lubricate one or more moving parts within the gearbox, wherein the same fluid used as the lubricant in the gearbox is used as the liquid coolant in the liquid cooling system. The EPS in a configuration can further include a gearbox conduit system to provide the lubricant to the gearbox to lubricate the one or more moving parts within the gearbox, wherein the gearbox conduit system is parallel to a motor controller conduit system to provide the liquid coolant to both the electric motor assembly and the at least one of the motor controllers. Alternatively, in an embodiment, the gearbox conduit system is in series with a motor controller conduit system to provide the liquid coolant to both the electric motor assembly and the at least one of the motor controllers.

[0123] The system optionally has two or more motor controllers, wherein at least two motor controllers communicate over a high-speed bus, and the system is capable of operating if one of the two or more motor controllers is degraded, faulty, or inoperable. Each motor controller according to an embodiment has at least two digital Controller Area Network communication interfaces to receive power input commands, wherein at least one the digital Controller Area Network communication interfaces is redundant. The system in an embodiment further includes one or more system controllers for receiving control input and outputting power input commands to the one or more motor controllers. The motor controller optionally receives temperature data and / or pressure data from the electric motor assembly and / or the cooling system of the EPS, andadditionally or alternatively receives information on the main shaft of the electric motor including at least one of the group consisting of speed, angular position, and combinations thereof. In an aspect, the system includes one or more system controllers for receiving control input and outputting power input commands to one or more motor controllers.

[0124] The electric motor used in the EPS preferably uses a stator module that features two or more independent multiphase windings. The modular electric motor uses two (dual), 3-phase architecture which provides redundancy and graceful degradation should a fault occur. It can be appreciated that each motor module in the electric motor can have more or less separate windings, more or less electric HVAC phases, and more or less electric power connector boxes. The power supplied to the electric motor in the EPS is controlled and regulated by the motor controller to produce torque and / or regulate the rotational speed of the main shaft in the electric motor. The motor controller is also responsible for identifying and managing fault conditions that arise within the electric motor and within the motor controller itself. By having two independent motor controllers controlling motor modules that are independent and each supply power to the electric motor, faults within either the electric motor controller or the electric motor can be contained within the affected module.

[0125] The EPS systems have electric motors that use liquid cooling as does the motor controller or power supply unit use liquid cooling, and in one or more embodiments both the electric motor(s) and motor controlled s) use the same liquid coolant in an aspect in the same single system to achieve high thermal performance and efficiency. In yet a further embodiment, the same fluid used to cool the electric motor(s) and / or the electric motor controller(s) is fed to the electric motor as a lubricant to lubricate the bearing and / or other components in the electric motor. In another embodiment the same fluid used to cool the electric motor(s) and / or the electric motor controller(s) is feed to a drive train for use as a lubricant and is feed to the electric motor for use as a lubricant.

[0126] With respect to the above description, it is to be realized that the dimensional relationship for the parts of the system includes variations in size, materials, shape, form, function and the manner of operation as would be known to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the invention.

[0127] In the claims, the term “comprises / comprising” does not exclude the presence of other elements, features, or steps. Furthermore, although individually listed, a plurality of means, elements, or method steps may be implemented by. e.g., a single unit, element, or piece.Additionally, although individual features may be included in different claims, these may advantageously be combined, and their inclusion individually in different claims does not imply that a combination of features is not feasible and / or advantageous. In addition, singular references do not exclude a plurality. The terms “a”, “an”, “first”, “second”, etc., do not preclude a plurality. Reference signs or characters in the disclosure and / or claims are provided merely as a clarifying example and shall not be construed as limiting the scope of the claims in any way.

[0128] Those skilled in the art will recognize that the disclosed and illustrated EPS has many applications, may be implemented in various manners and. as such is not to be limited by the foregoing embodiments and examples, but it is intended to cover modifications within the spirit and scope of the invention. For example, use of the EPS in helicopters and / or other mobile vehicles or aircraft is contemplated. While fundamental features of the invention have been shown and described in exemplary embodiments, it will be understood that omissions, substitutions, and changes in the form and details of the disclosed embodiments of the EPS may be made by those skilled in the art without departing from the spirit of the invention. Any number of the features of the different embodiments described herein may be combined into a single embodiment. The locations of particular elements, for example, the cooling system, the power connections, the electric power connector boxes, the sensors and communication lines, etc., may be altered.

[0129] Alternate embodiments are possible that have features in addition to those described herein or may have less than all the features described. Functionality may also be, in whole or in part, distributed among multiple components, in manners now known or to become known. The discussion of any embodiment is meant only to be explanatory and is not intended to suggest that the scope of the disclosure, including the claims, is limited to these embodiments. In other words, while illustrative embodiments of the disclosure have been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed, and that the appended claims are intended to be construed to include such variations, except as limited by the prior art.

Claims

CLAIMSWe claim:

1. A system to convert electrical power to torque, the system comprising:one or more motor controllers, each motor controller configured to receive power input commands and to receive high-voltage, direct-current (HVDC) input power of between 400-850 DC volts and convert the HVDC input power to multiphase high-voltage, alternating-current (HVAC) output power at a fundamental frequency of about 10 hertz to about 1000 hertz, wherein each motor controller varies its respective multiphase HVAC output power in response to the power input commands received; andan electric motor assembly having a main shaft for supplying torque, the electric motor configured and adapted to receive input power as the multiphase HVAC from the one or more motor controllers to rotate the main shaft, wherein the electric motor assembly has one or more rotor assemblies rotatable relative to one or more stator modules to rotate the main shaft, each rotor assembly having a plurality of magnets arranged around an outer periphery of a hub to form between 14 to 20 magnetic poles and each stator module has a plurality of stator windings and a stator core having a plurality of spaced apart projecting structures forming between 18 to 27 slots, each one of the plurality of stator windings wrapped about one of the projecting structures and configured to receive the multiphase HVAC power from the one or more motor controllers.

2. The system of claim 1, wherein the one or more motor controllers in combination generate between 160 kW and 500 kW of HVAC output power.

3. The system of claim 2, wherein each motor controller generates between 80 kW and 250 kW of HVAC output power.

4. The system of claim 1, each motor controller outputs about 10 volts RMS to about 850 Volts RMS and about zero to about 700 amps RMS at the frequency range of about 10 Hertz to about 1000 Hertz.

5. The system of claim 1, further comprising a cooling system having a coolant, wherein the coolant is configured to flow through both the electric motor assembly and at least one of the motor controllers.

6. The system of claim 5, wherein each of the one or more motor controllers has a housing, wherein the coolant is a liquid that flows through the housing of at least one of the motor controllers.

7. The system of claim 6, wherein the system comprises at least two motor controllers and the system is configured so that the liquid coolant flows through at least two of the housings of the motor controllers in parallel and through the electric motor assembly in series with the at least two motor controllers.

8. The system of claim 7, wherein the liquid coolant comprises turbine oil.

9. The system of claim 5, wherein the liquid coolant flows through a first pathway through the at least one of the motor controllers and through at least one of the plurality of stator windings in the electric motor assembly and the liquid coolant flows through a second pathway in the electric motor assembly through at least one of a lubrication group consisting of: a bearing, a spline, a shaft coupling, and combinations thereof to lubricate the at least one of the lubrication group.

10. The system of claim 9, wherein the second pathway is pressurized.

11. The system of claim 9, wherein the first pathway through the electric motor assembly is parallel to the second pathway through the electric motor assembly.

12. The system of claim 9, wherein the second pathway comprises a drive end channel to lubricate at least one of a drive end lubrication group consisting of: a drive end bearing, a drive end spline, a drive end shaft coupling, and combinations thereof to lubricate the at least one of the drive end lubrication group and a lead end channel to lubricate at least one of a lead end lubrication group consisting of: a lead end bearing, a lead end spline, a lead end shaft coupling, and combinations thereof to lubricate the at least one of the lead end lubrication group.

13. The system of claim 9, wherein the second pathway comprises a spline conduit configured to deliver coolant fluid to a shaft coupling in the electric motor assembly and a separate bearing conduit configured to deliver coolant fluid to a bearing in the electric motor assembly.

14. The system of claim 5, wherein the cooling system comprises one or more vents.

15. The system of claim 5, wherein the liquid cooling system contains one or more temperature sensors and data from the temperature sensors is communicated to one or more of the motor controllers for processing.

16. The system of claim 5, wherein the liquid cooling system contains one or more pressure sensors and data from the pressure sensors is communicated to one or more of the motor controllers for processing.

17. The system of claim 5, wherein the cooling system further contains a reservoir to contain the liquid coolant, a conduit system to channel the liquid coolant at least between the one or more motor controllers and the electric motor assembly, and at least one pump to pump the liquid coolant.

18. The system of claim 5, wherein a first end of the main shaft is connectable to a gear box that drives a propulsor of an aircraft and a second end of the main shaft drives a pump to circulate the liquid coolant in the cooling system.

19. The system of claim 18. wherein the pump is directly driven by the main shaft and circulates 25-70 liters per minute (LPM) of oil as the liquid coolant.

20. The system of claim 5, wherein the electric motor assembly is configured to receive fluid as a lubricant to lubricate one or more moving parts within the electric motor assembly, wherein the same fluid used as lubricant in the electric motor assembly is used as coolant in the liquid cooling system.

21. The system of claim 20, wherein the electric motor assembly further comprises a jet nozzle to spray the lubricant to lubricate one or more bearings that are configured to support the main shaft, wherein the jet nozzle receives the lubricant under pressure.

22. The system of claim 1, wherein the one or more motor controllers are configured to produce and supply two independent multi-phases of HVAC output power and each stator module in the electric motor is configured to receive at least two independent multiphases of HVAC output power from the one or more motor controllers.

23. The system of claim 22, wherein a single motor controller having a single housing with a single cooling channel to receive liquid coolant produces and supplies the two independent multi-phases of HVAC output power, wherein the single motor controller contains two independent circuits, each to produce one of the independent multiphase HVAC outputs.

24. The system of claim 1 , wherein the hub of at least one rotor assembly comprises at least one of cooling group to facilitate cooling of the electric motor assembly, wherein the cooling group consisting of at least one of: one or more twisted blades to assist with axially moving air through the electric motor assembly, one or more radial vanes to assist with moving air radially on the at least one rotor assembly, and combinations thereof.

25. The system of claim 1, wherein the plurality of stator windings on at least one of the one or more stator modules are arranged as at least two independent sets of a plurality of stator windings, each independent set of a plurality of windings is electrically isolated from the other set of a plurality of stator windings.

26. The system of claim 25, wherein a first independent set of a plurality of windings is spaced and separated from a second independent set of plurality of stator windings to resist magnetic coupling between sets of stator windings.

27. The system of claim 25, wherein the first set of independent stator windings comprises at least two groups of a plurality of stator windings, each of the plurality of stator windings in each group is electrically connected together and electrically isolated from the plurality of windings in the other groups.

28. The system of claim 27, wherein there are two independent sets of a plurality of windings in at least one of the one or more stator modules, wherein each independent set of stator windings has three groups of a plurality of stator windings, each of the plurality of stator windings in each group of each independent set of stator windings is electrically connected together and electrically isolated from each of the plurality of windings in each other group of stator windings.

29. The system of claim 28, wherein the electric motor assembly is configured to receive two independent supplies of three phase, high voltage, alternating current, and wherein the first independent supply of three phase, high voltage, alternating current is configured to supply the first independent set of three groups of a plurality of stator windings, each of the three groups of stator windings in the first set configured to receive a different phase of the first independent supply of three phase, high voltage, alternating current, and wherein the second independent supply of three phase, high voltage, alternating current is configured to supply the second independent set of three groups of a plurality of stator windings, each of the three groups ofstator windings in the second set configured to receive a different phase of the second independent supply of three-phase, high-voltage, alternating current.

30. The system of claim 29. wherein the first independent set of a plurality of windings is positioned on a first half of the at least one of the one or more stator modules and the second independent set of a plurality of stator windings is positioned on the second half of the at least one of the one or more stator modules wherein the first half is spaced from and separated from the second half to resist magnetic coupling between the first and second independent sets of stator windings.

31. The system of claim 1, wherein each magnetic pole comprises at least three magnets with their magnetic poles oriented in different directions.

32. The system of claim 1, wherein the electric motor assembly comprises at least two sets of three electrical connectors to receive the multiphase HVAC from the one or more motor controllers.

33. The system of claim 5, further comprising a gearbox that receives rotational power from the electric motor assembly and drives a propulsor of an aircraft, wherein the gearbox is configured to receive fluid as a lubricant to lubricate one or more moving parts within the gearbox, wherein the same fluid used as the lubricant in the gearbox is used as the liquid coolant in the liquid cooling system.

34. The system of claim 33. further comprising a gearbox conduit system to provide the lubricant to the gearbox to lubricate the one or more moving parts within the gearbox, wherein the gearbox conduit system is parallel to a motor controller conduit system to provide the liquid coolant to both the electric motor assembly and the at least one of the motor controllers.

35. The system of claim 33, further comprising a gearbox conduit system to provide the lubricant to the gearbox to lubricate the one or more moving parts within the gearbox, wherein the gearbox conduit system is in series with a motor controller conduit system to provide the liquid coolant to both the electric motor assembly and the at least one of the motor controllers.36 The system of claim 1, configured as a propulsion system, wherein the main shaft of the electric motor assembly is configured to supply torque to a propulsor of an aircraft.

37. The system of claim 1 , further comprising two or more motor controllers, wherein at least two motor controllers communicate over a high speed bus, and the system is capable of operating if one of the two or more motor controllers is degraded, faulty, or inoperable.

38. The system of claim 1, further comprising one or more system controllers for receiving control input and outputting power input commands to the one or more motor controllers.

39. The system of claim 1, wherein each motor controller has at least two digital Controller Area Network communication interfaces to receive power input commands, wherein at least one the digital Controller Area Network communication interfaces is redundant.

40. The system of claim 1, wherein the motor controller receives at least one of a group consisting of: temperature data, pressure data, and combinations thereof from the electric motor assembly.

41. The system of claim 1, wherein at least one of the one or more motor controllers receives information on the main shaft of the electric motor assembly including at least one of the group consisting of speed, angular position, and combinations thereof.

42. The system of claim 1, wherein the one or more motor controller receives control input and in response the one or more motor controllers varies HVAC power to the one or more electric motor assemblies to vary at least one of a shaft group consisting torque and / or speed output of the one or more electric motor assemblies.

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