Hybrid radial axial motor

Abstract

It provides improved efficiency, greater flexibility, and reduced torque fluctuations in the propulsion system. [Solution] The torque generation method includes the steps of: receiving a first current in a radial motor having a rotor arm; generating a radial magnetic flux in a first direction in response to the first current; generating a first torque in the rotor arm based on the radial magnetic flux; receiving a second current in a first axial motor positioned on the first side of the radial motor inside the housing and positioned inside the radial motor; generating a first axial magnetic flux in a second direction; generating a second torque in the rotor arm based on the first axial magnetic flux; and receiving a third current in a second axial motor positioned on the second opposite side of the radial motor inside the housing and positioned inside the radial motor.

Description

Technical Field

[0001] Cross-Reference to Related Applications

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 088,388, entitled "A Hybrid Radial-Axial Motor," filed on October 6, 2020, the disclosure of which is hereby incorporated by reference in its entirety for all purposes.

Background Art

[0002]

[0002] Integrated electric propulsion is becoming an attractive solution for commercial and marine vessels. Integrated electric propulsion systems decouple the propulsion of a ship from gas turbines and diesel engines and increase the flexibility of the plant layout and fuel economy compared to more conventional mechanical drive solutions. Additionally, integrated electric propulsion systems significantly reduce the acoustic characteristics associated with large reduction gearboxes. Typically, an integrated electric propulsion plant is sized to handle peak loads at rated speed. By using a single shaft, the electric machine can be operated at high speed and a high power density can be achieved. However, there may be a less efficient low-speed, low-power mode for larger propulsion plants (e.g., patrol mode or cruise mode).

[0003]

[0003] Despite progress in the field of integrated electric propulsion, improved methods and systems related to electric systems are needed in the art.

Summary of the Invention

[0004]

[0004] This application relates generally to the field of electric motors, and more particularly to hybrid radial-axial flux motors. In some embodiments, the rotor includes magnetic elements for the radial flux motor and magnetic elements for the axial flux motor. The radial flux motor and the axial flux motor operate independently to provide advantages not available in the prior art. Embodiments of the present invention are applicable to a variety of systems including electric motors, including marine-based, vehicle-based, and aircraft systems.

[0005]

[0005] In various embodiments, the electromachine includes a housing, a radial motor disposed inside the housing, the radial motor being configured to generate a radial magnetic flux in a first direction, the radial magnetic flux influencing a first magnetic unit to generate a first torque on a rotor arm mounted on a shaft, an axial motor disposed inside the housing, the axial motor being configured to generate an axial magnetic flux in a second direction, the axial magnetic flux influencing a second magnetic unit to generate a second torque on a rotor arm mounted on a shaft, and a controller or load configured to independently control the first and second torques.

[0006]

[0006] In various embodiments, the controller controls the d-axis current and q-axis current applied to at least one of a radial motor, an axial motor, or a combination thereof in order to reduce torque vibration on the shaft.

[0007]

[0007] In various embodiments, the radial motor or axial motor is replaced by a gear set.

[0008]

[0008] In various embodiments, the radial motor includes an induction motor.

[0009]

[0009] In various embodiments, the radial motor is composed of a wound-field synchronous motor.

[0010]

[0010] In various embodiments, the radial motor is configured as a DC motor, as described in claim 1.

[0011]

[0011] In various embodiments, the radial motor is composed of a universal motor.

[0012]

[0012] In various embodiments, the radial motor is composed of a reluctance motor.

[0013]

[0013] In various embodiments, two or more axial motors are located inside the housing.

[0014]

[0014] In various embodiments, the axial motor includes an induction motor.

[0015]

[0015] In various embodiments, the electromachine includes a transverse flux motor in a housing which generates a transverse flux in a third direction, and the transverse flux affects a third magnetic unit which generates a third torque on a rotor arm attached to a shaft.

[0016]

[0016] In one aspect of the present disclosure, the propulsion system includes a housing; a radial motor located within the housing, configured to generate a radial flux in a first direction, the radial flux influencing a first magnetic unit to generate a first torque on a rotor arm mounted on a shaft; an axial motor located within the housing, configured to generate an axial flux in a second direction, the axial flux influencing a second magnetic unit to generate a second torque on a rotor arm mounted on a shaft; and a controller configured to independently control the first and second torques.

[0017]

[0017] In various embodiments, the controller controls the d-axis current and q-axis current applied to at least one of a radial motor, an axial motor, or a combination thereof in order to reduce or amplify torque vibrations on the shaft.

[0018]

[0018] In various embodiments, the radial motor or axial motor is replaced by a gear set.

[0019]

[0019] In various embodiments, the radial motor includes an induction motor.

[0020]

[0020] In various embodiments, the axial motor includes an induction motor.

[0021]

[0021] In various embodiments, the propulsion system includes two or more axial motors within a housing.

[0022]

[0022] In various embodiments, the propulsion system includes a transverse flux motor within a housing, which generates a transverse flux in a third direction, and the transverse flux affects a third magnetic unit to generate a third torque on a rotor arm attached to a shaft.

[0023]

[0023] In one aspect of the present disclosure, a method for generating torque on a shaft for a propulsion system includes receiving a first current at a radial motor having a rotor arm attached to the shaft, the radial motor being positioned within a housing. The method can include generating a radial magnetic flux in a first direction in response to the first current. The method can include generating a first torque on the rotor arm based on the radial magnetic flux interacting with a first magnetic unit. The method can include receiving a second current at an axial motor, the axial motor being positioned within the housing. The method can include generating an axial magnetic flux in a second direction. The method can include generating a second torque on the rotor arm based on the axial magnetic flux interacting with a second magnetic unit.

[0024]

[0024] In various embodiments, the first current includes a first set of d-axis current and q-axis current applied to the radial motor.

[0025]

[0025] In various embodiments, the second current includes a second set of d-axis current and q-axis current applied to the axial motor.

[0026]

[0026] In various embodiments, the first torque is characterized by a first vibration amplitude, the second torque is characterized by a second vibration amplitude, and the sum of the first torque and the second torque is characterized by an integrated vibration amplitude that is less than both the first vibration amplitude and the second vibration amplitude.

[0027]

[0027] In various embodiments, the method includes setting the first current to a first maximum value and setting the second current to a second maximum value to operate the propulsion system in a boost mode.

[0028]

[0028] In various embodiments, the method includes operating the propulsion system in a cost mode by selectively reducing or de - energizing the first or second current, or a combination thereof.

[0029]

[0029] According to the present invention, more advantages are achieved than in the prior art. For example, embodiments of the present invention can provide improved efficiency (especially low power requirements), greater flexibility, and improved control of torque fluctuations in the propulsion system.

[0030]

[0030] The radial - axial flux (RADAX) hybrid motor configuration counteracts the reduction in system efficiency by integrating one or more magnetically and electrically insulated axial - flux permanent - magnet (AFPM) machines into an integrated electric propulsion motor. Thereby, while the secondary winding carries the propulsion load, the primary winding can be demagnetized during off - peak load conditions (e.g., patrol, low - speed transit, coast). The RADAX configuration provides an improvement in volume density since the AFPM motor is placed within the primary propulsion motor and otherwise occupies unused space. The RADAX configuration disclosed herein forms a hybrid permanent - magnet solution that creates a new hybrid induction permanent - magnet motor. The disclosed RADAX configuration provides secondary advantages such as fault tolerance and the ability to cancel out axial thrust and ship service power from propulsive forces within the propulsion shaft.

[0031]

[0031] The RADAX concept can be applied to the two most popular types of propulsion motors, namely the radial - flux induction motor (RFIM) and the radial - flux permanent - magnet (RFPM) propulsion motor.

[0032]

[0032] The RADAX concept enables the integration of multiple electromagnetic topologies into a single propulsion system, allowing the designer to mix and adapt the best topology for each load scenario. As a result, a compact and highly efficient propulsion system is realized, improving not only the fault tolerance but also the capabilities of the propulsion system.

[0033]

[0033] These and other embodiments of the present disclosure, along with many of their advantages and features, will be described in more detail below in reference to the text and accompanying drawings. [Brief explanation of the drawing]

[0034] [Figure 1] This is an exemplary cross-sectional perspective view of a radial-axial permanent magnet propulsion motor according to one embodiment of the present invention. [Figure 2] This is an exemplary cross-sectional perspective view of a first configuration of a radial-axial propulsion motor according to one embodiment of the present invention. [Figure 3] This is an isometric view of the first configuration of a radial-axial propulsion motor according to one embodiment of the present invention. [Figure 4] This is an exemplary cross-sectional perspective view of a second configuration of a radial-axial propulsion motor according to one embodiment of the present invention. [Figure 5] This is an isometric view of a second configuration of a radial-axial propulsion motor according to one embodiment of the present invention. [Figure 6] This is an exemplary cross-sectional perspective view of a third configuration of a radial-axial propulsion motor according to one embodiment of the present invention. [Figure 7] This is an isometric view of a third configuration of a radial-axial propulsion motor according to one embodiment of the present invention. [Figure 8] This is an exemplary cross-sectional perspective view of a fourth configuration of a radial-axial propulsion motor according to one embodiment of the present invention. [Figure 9] This is an isometric view of a fourth configuration of a radial-axial propulsion motor according to one embodiment of the present invention. [Figure 10] This is an exemplary cross-sectional perspective view of a fifth configuration of a radial-axial propulsion motor according to one embodiment of the present invention. [Figure 11] This is an isometric view of a fifth configuration of a radial-axial propulsion motor according to one embodiment of the present invention. [Figure 12] This is an exemplary cross-sectional perspective view of a sixth configuration of a radial-axial propulsion motor according to one embodiment of the present invention. [Figure 13] This is an isometric view of a sixth configuration of a radial-axial propulsion motor according to one embodiment of the present invention. [Figure 14] This is an exemplary cross-sectional perspective view of a seventh configuration of a radial-axial propulsion motor according to one embodiment of the present invention. [Figure 15] This is an isometric view of the seventh configuration of a radial-axial propulsion motor according to one embodiment of the present invention. [Figure 16] This figure shows a plot of torque versus electrical angle for a first state of a radial-axial propulsion motor according to one embodiment of the present invention. [Figure 17] This figure shows a plot of torque versus electrical angle for a second state of a radial-axial propulsion motor according to one embodiment of the present invention. [Figure 18] This figure shows a plot of torque versus electrical angle for a third state of a radial-axial propulsion motor according to one embodiment of the present invention. [Figure 19] This figure shows a plot of torque versus electrical angle for a fourth state of a radial-axial propulsion motor according to one embodiment of the present invention. [Figure 20] This figure shows a force plot over time for a first state of a radial-axial propulsion motor according to one embodiment of the present invention. [Figure 21] This figure shows a force plot over time for a second state of a radial-axial propulsion motor according to one embodiment of the present invention. [Figure 22] This figure shows a force plot over time for a third state of a radial-axial propulsion motor according to one embodiment of the present invention. [Figure 23] This figure shows a simplified electric propulsion system for ships according to one embodiment of the present invention. [Figure 24] This is a flowchart illustrating an exemplary process for generating torque in a hybrid radial-axial motor according to one embodiment of the present invention. [Modes for carrying out the invention]

[0035]

[0058] Similar references and symbols in various drawings indicate similar elements according to a particular exemplary implementation. Furthermore, multiple instances of an element may be indicated by following the element's first and second numbers with letters or hyphens.

[0036]

[0059] For a detailed description of exemplary implementation configurations, please refer to the attached drawings. The same reference numeral in different drawings may indicate the same or similar elements.

[0037]

[0060] The disclosed radial-axial flux (RADAX) hybrid motor configuration counteracts the reduction in system efficiency caused by integrating one or more magnetically and electrically isolated axial flux permanent magnet (AFPM) machines into a hybrid electric motor, allowing the primary winding to be demagnetized during off-peak load conditions (e.g., patrol speed, low-speed transit, etc.) while the secondary winding carries the propulsion load. The RADAX configuration offers improved volume density because the AFPM motor is located within the primary propulsion motor, occupying otherwise unused space. The disclosed RADAX configuration offers fault tolerance, as well as secondary benefits such as vehicle / ship / aircraft service power derived from axial thrust and propulsion within the propulsion shaft.

[0038]

[0061] As used herein, a radial motor generates a radial magnetic flux that flows perpendicular to the axial direction of the machine, along the radius of the axial shaft of the machine. An axial magnetic flux motor generates an axial magnetic flux that flows in the axial direction of the machine.

[0039]

[0062] Conventional electric motors and generators are limited to a single operating mode in which the motor simply provides torque and rotational motion to a load coupled to the motor shaft. In RADAX configurations, where both primary and secondary motors, either the primary or secondary motor, or any combination of the primary and secondary motors drive a common shaft, several operating modes can be used.

[0040]

[0063] Figure 1 shows an exemplary cross-sectional perspective view of a radial-axial permanent magnet propulsion motor according to one embodiment of the present invention. In the exemplary configuration, the primary motor may include radial flux permanent magnets, and the secondary motor may include two axial flux permanent magnet motors.

[0041]

[0064] In a radial flux motor, the magnetic field or magnetic flux extends radially with respect to the direction of the rotor shaft. In Figure 1, the rotor shaft is a common rotor shaft 102.

[0042]

[0065] An axial flux motor has a geometric shape in its motor structure where there is a gap between the rotor and the stator. Therefore, the direction of the magnetic flux between them is aligned parallel to the axis of rotation, rather than radially, as in a radial flux motor.

[0043]

[0066] Axial flux motors can offer significantly higher power density for several reasons. Firstly, in axial flux machines, the torque-generating magnets traverse radially along the rotor disk. This allows the radial portion of the rotor structure to generate electromagnetic torque, eliminating the need for concentric rotor hoops and minimizing the weight and volume of the motor assembly. Secondly, in radial flux motors, a large portion (around 50%) of the windings is ineffective (the portion located outside the stator teeth, used only to form a loop, known as "coil overhang"). Coil overhang is geometrically consistent across both ranges of the motor and introduces additional electrical resistance (e.g., heat dissipation) without contributing to torque generation. Conversely, the end turns of an axial flux stator are geometrically inconsistent due to the motor's inherent "donut shape." In axial flux motors, inner diameter end turns traverse smaller tangential distances than outer diameter end turns, minimizing end turn resistance and the resulting thermal load. As a result, radial flux motors have a generally lower power / weight ratio compared to axial flux motors.

[0044]

[0067] The radial-axial motor shown in Figure 1 combines the advantages of both radial and axial motors, resulting in a more efficient and power-density machine. Furthermore, the radial and axial motors can be controlled independently to fine-tune motor performance and reduce undesirable torque fluctuations in the common shaft 102. By reducing the torque fluctuations of the common shaft, vibrations can also be controlled (increased or decreased). Vibrations in equipment cause wear and tear and enhance the detectability and identifiability of the vessel through its sonic characteristics. Therefore, one of the advantages of the radial-axial motor is that it enables more efficient operation, especially at low speeds, and reduces undesirable power fluctuations in the shaft.

[0045]

[0068] Figure 1 shows the RADAX motor end wall 101 and motor frame 103. One or more rotor assemblies can be mounted on the common motor shaft 102 inside the motor frame 103. The primary rotor assembly 104 may include a circular disk 108 having an inner portion near the center of the circular disk 108 and an outer portion 110 along the circumference of the circular disk 108. The outer portion 110 of the rotor assembly 104 may be T-shaped and include a rotor assembly surface 111. The primary rotor assembly can be mounted on the common motor shaft 102 at the inner portion 106. Permanent magnets 105 can be fixed on the outer portion 110 on the rotor assembly surface 111 at the T-shaped end of the rotor assembly 104. In some embodiments, instead of permanent magnets 105, an induction rotor including several rotor windings is used as the primary rotor. The primary motor stator 112 can be mounted on the inner surface of the circular RADAX motor end wall 101. The primary motor stator 112 can be installed such that an air gap 113 exists between the primary rotor assembly 104 and the primary motor stator 112. The first current can pass through the primary stator assembly 112 to generate a magnetic field 115. The magnetic field 115 generated by the primary stator assembly 112 can affect the permanent magnet 105 fixed to the surface 111 of the primary motor rotor 104, causing a radial force that rotates the common motor shaft 102. A bearing 107 can be installed around the common motor shaft 102.

[0046]

[0069] The RADAX motor frame 103 may include RADAX motor end walls 101. The secondary motor stator 114 can be fixed along each inner portion of the RADAX motor end walls 101. The secondary motor stator assembly 114 may include a circular stator assembly surrounding the common motor shaft 102. A second current can be applied to the circular stator assembly 114 to generate a magnetic field 121. The secondary rotor assembly 116 can be fixed to the common motor shaft 102 such that an air gap 117 exists between the outer surface of the secondary rotor assembly 116 and the inner surface of the secondary motor stator assembly 114. One or more permanent magnets 119 can be fixed to the outer surface of the secondary rotor assembly 116 so that the permanent magnets 119 are affected by the magnetic field 121 generated by the secondary motor stator assembly 114. The secondary rotor assembly 116 can be mounted inside the secondary motor stator assembly 114 on the common motor shaft 102. The magnetic field 121 generated by the secondary motor stator assembly 114 can influence the magnetic field generated by the permanent magnet 119 on the secondary rotor assembly 116, causing a tangential force that rotates the common motor shaft 102.

[0047]

[0070] The first current may be separate and independent from the second independent current. In some embodiments, additional independent currents may be applied (e.g., a third current, a fourth current, a fifth current, etc.). Each of the independent currents (e.g., the first current, the second current, etc.) can be controlled independently. For example, the amperage, voltage, and d-axis and q-axis inductances can be controlled and adjusted independently.

[0048]

[0071] d-axis and q-axis inductance are the inductance measured when the magnetic flux path passes through the rotor relative to the magnetic poles. d-axis inductance is the inductance measured when the magnetic flux passes through the magnetic poles. q-axis inductance is the inductance measure when the magnetic flux passes between the magnetic poles.

[0049]

[0072] In induction machines, the rotor flux linkage is the same between the d-axis and the q-axis. However, in permanent magnet machines, the magnets reduce the amount of iron available for flux linkage. The permeability of the magnets is close to that of air. Therefore, the magnets can be seen as an air gap. The magnets are in the flux path when moving along the d-axis. The flux path along the q-axis does not intersect with the magnets. Therefore, more iron can be coupled to the q-axis flux path, resulting in a larger inductance. A motor with embedded magnets has a q-axis inductance that is greater than the d-axis inductance. A motor with surface-mount magnets has nearly identical q-axis and d-axis inductances because the magnets are outside the rotor and do not limit the amount of iron coupled by the stator field.

[0050]

[0073] Each of the primary and secondary motors can independently generate torque to rotate the common motor shaft 102 in the same direction around its axis. By reversing their respective field fluxes, each of the primary and secondary motors can independently generate torque to rotate the common motor shaft 102 in opposite directions. The radial and axial motors can be positioned within the housing to reduce the crossing flux from either the radial or axial motor.

[0051]

[0074] Figure 2 shows an exemplary cross-sectional perspective view of a first configuration of a radial-axial propulsion motor 200 according to one embodiment of the present invention. In the first configuration, the primary motor may include a radial flux permanent magnet motor. The secondary motor may include two axial flux permanent magnet motors. Although not shown in Figure 2, the RADAX motor may include a motor end wall 101 and a motor frame 103, as shown in Figure 1. One or more rotor assemblies can be mounted on a common motor shaft 202 inside the motor frame 103. The primary rotor assembly 204 may include a circular disk having an inner portion 206 near the center of the circular disk and an outer portion 210 along the circumference of the circular disk. The outer portion 210 of the rotor assembly may be T-shaped and include a rotor assembly surface. The primary rotor assembly 204 can be mounted on the common motor shaft 202 at the inner portion 206. One or more permanent magnets can be fixed to the outer portion 210 of the primary rotor assembly surface at the T-shaped end of the primary rotor assembly 204. The primary stator assembly 212 can be mounted on the inner surface of the circular RADAX motor frame 103, as shown in Figure 1. The primary stator assembly 212 can be positioned such that an air gap exists between the primary rotor assembly 204 and the primary motor stator 212. A first current can pass through the primary stator assembly 212 to generate a magnetic field. The magnetic field generated by the primary stator assembly 212 can affect the permanent magnets fixed to the surface of the primary motor rotor 204, causing a radial force that rotates the common motor shaft 202.

[0052]

[0075] A RADAX motor frame can include two RADAX motor end walls. A secondary motor stator assembly 214 can be fixed along the inner portion of each RADAX motor end wall. The secondary motor stator assembly 214 can include a circular stator assembly surrounding a common motor shaft 202. A second current can be applied to the circular stator assembly 214 to generate a magnetic field. The secondary rotor assembly 216 can be fixed to the common motor shaft 202 such that there is a gap between the outer surface of the secondary rotor assembly 216 and the inner surface of the secondary motor stator assembly 214. One or more permanent magnets can be fixed to the outer surface of the secondary rotor assembly 216 so that the permanent magnets are affected by the magnetic field generated by the secondary motor stator assembly 214. The secondary rotor assembly 216 can be mounted inside the secondary motor stator assembly 214 on the common motor shaft 202.

[0053]

[0076] Figure 3 shows an isometric view of the first configuration of a radial-axial permanent magnet propulsion motor 300 with the motor housing removed, according to one embodiment of the present invention. Figure 3 shows the primary rotor assembly 304. The primary stator assembly 312 surrounds the radial flux permanent magnet motor 400. Figure 3 shows the secondary motor stator assembly 314, one of two secondary motor stator assemblies. The primary rotor assembly 304 can be seen inside the primary stator assembly 312. The common motor shaft 302 can be seen emerging from a recess in the secondary motor stator assembly 314.

[0054]

[0077] Figure 4 shows an exemplary cross-sectional perspective view of a second configuration of a radial-axial propulsion motor driving a common motor shaft 402 according to one embodiment of the present invention. In the second configuration, the primary rotor assembly 404 may include a radial flux permanent magnet motor. The secondary motor may include four axial flux permanent magnet motors. Each of the four axial flux permanent magnet motors may be controlled individually using a controller. Both of the two additional axial flux permanent magnet motors increase the total torque generated by the radial-axial propulsion motor and allow for greater control of torque fluctuations on the common shaft compared to the first configuration of the radial-axial propulsion motor.

[0055]

[0078] In this configuration, the additional secondary motors are housed within a single motor housing. Furthermore, the secondary motors can be operated simultaneously, increasing torque generation on the common shaft. The secondary motors can operate in a staggered configuration for applications involving increasing and decreasing loads, similar to a car gearbox. In this scenario, a single secondary motor operates for light loads and high-efficiency torque generation, and as the load ramps up, the second secondary motor is activated. This load scenario continues down to all secondary motors, with the primary motors actively generating torque on the common shaft. Conversely, the RADAX configuration allows the motors to be stopped as torque requirements decrease.

[0056]

[0079] Although not shown, a second configuration of the RADAX motor may include the RADAX motor end wall and motor frame. Inside the motor frame, the primary rotor assembly 404 can be mounted on the common motor shaft 402. The primary rotor assembly 404 may include a circular disk having an inner portion 406 at the center of the circular disk and an outer portion 410 along the circumference of the circular disk. The outer portion 410 of the primary rotor assembly 404 may be T-shaped and include a rotor assembly surface perpendicular to the surface of the circular disk. The primary rotor assembly 404 can be mounted on the common motor shaft 402 by the inner portion 406 of the primary rotor assembly 404. One or more permanent magnets can be fixed to the primary rotor assembly surface at the T-shaped end of the primary rotor assembly 404. The primary stator assembly 412 can be mounted on the inner surface of the circular RADAX motor frame. The primary stator assembly 412 can be installed such that an air gap exists between the primary rotor assembly 404 and the primary stator assembly 412. The first current can pass through the primary stator assembly 412 to generate a magnetic field. The magnetic field generated by the primary stator assembly 412 can affect permanent magnets fixed to the surface of the primary motor rotor, causing a radial force that rotates the common motor shaft 402.

[0057]

[0080] A RADAX motor frame may include two RADAX motor end walls. A secondary motor stator assembly 414 can be fixed along the inner portion of each RADAX motor end wall. The secondary motor stator assembly 414 may include a circular stator surrounding a common motor shaft 402. A second current can be applied to the secondary motor stator assembly 414 to generate a magnetic field that produces axial magnetic flux. A secondary rotor assembly 416 can be mounted on the common motor shaft 402 inside the secondary motor stator assembly 414 such that a gap exists between the outer surface of the secondary rotor assembly 416 and the inner surface of the secondary motor stator assembly 414. One or more permanent magnets can be fixed to the outer surface of the secondary rotor assembly 416 so that the permanent magnets are affected by the magnetic field generated by the secondary motor stator assembly 414. In a second RADAX configuration, third and fourth pairs of secondary motor stator assemblies 414 and secondary rotor assemblies 416 can be installed inside the first and second pairs of secondary motor stator assemblies 414 and secondary rotor assemblies 416. The diameters of the third and fourth secondary motor stator assemblies 414 can be larger than the diameter of the first secondary motor stator assembly for mounting the stator assembly to the RADAX motor end wall.

[0058]

[0081] Figure 5 shows an isometric view of the second configuration of the radial-axial propulsion motor 500. Figure 5 shows the primary rotor assembly 504 mounted on the common motor shaft 502. The primary stator assembly 512 surrounds the radial flux propulsion motor 500. As shown in Figure 5, the second configuration of the radial-axial propulsion motor includes multiple secondary motor stator assemblies 414, two of which can be seen in Figure 5. The primary rotor assembly 504 can be seen inside the primary stator assembly 512. The common motor shaft 502 can be seen emerging from a recess in the secondary motor stator assembly 514.

[0059]

[0082] Figure 6 shows an exemplary cross-sectional perspective view of a third configuration of a radial-axial propulsion motor 600 according to one embodiment of the present invention. The third configuration of the radial-axial propulsion motor 600 may include a radial flux induction motor as the primary motor and two axial flux permanent magnet motors as secondary motors. In the third configuration, the primary rotor assembly 604 may include a radial flux induction motor mounted on a common motor shaft 602. A key advantage of AC induction motors is cost. AC induction can be relatively inexpensive to build. AC induction designs use laminated steel for both the stator and rotor, and these can be stamped almost simultaneously from the same sheet of material. In other words, the scrap rate is much lower than that of an average stamping job. In AC induction motors, the rotor always rotates at a slower speed than the magnetic field cycle. Permanent magnet motors tend to be more expensive than AC induction motors and are known to be more difficult to start. However, the advantages of permanent magnet motors include higher efficiency, smaller size (permanent magnet motors can be about one-third the size of most AC motors, making them much easier to install and maintain), and the ability of permanent magnet motors to maintain full torque even at low speeds.

[0060]

[0083] To compensate for the low load efficiency of a primary radial flux induction motor, a secondary permanent magnet motor can be used. Permanent magnet motors are more efficient than induction motors because they have windings on the rotor and therefore do not incur rotor winding losses. Furthermore, secondary motors are optimized for lower torque operation compared to primary radial flux motors. Thus, the primary motor can be de-excited during low-torque operation, allowing one or more secondary motors to provide torque to the common motor shaft. In this configuration, the optimized permanent magnet motors generate torque more efficiently, reducing overall power consumption compared to a primary radial flux motor operating alone.

[0061]

[0084] The primary rotor assembly 604 includes one or more coils. A first current can be passed through one or more coils to generate a magnetic field. The primary stator assembly 612 can be mounted on the inner surface of the circular RADAX motor frame. The primary stator assembly 612 can be installed such that an air gap exists between the primary rotor assembly 604 and the primary stator assembly 612. A second current can pass through the primary stator assembly 612 to generate a magnetic field. The magnetic field generated by the primary stator assembly 612 can influence the magnetic field generated by the primary rotor assembly 604, causing a radial force that rotates the common motor shaft 402.

[0062]

[0085] The RADAX motor frame may include two RADAX motor end walls. The secondary motor stator assembly 614 can be fixed along the inner portion of each of the two RADAX motor end walls. The secondary motor stator assembly 612 may include a circular stator assembly surrounding the common motor shaft 602. A third current can be applied to the secondary motor stator assembly 614 to generate a magnetic field. The secondary rotor assembly 616 can be fixed to the common motor shaft 602 such that a gap exists between the outer surface of the secondary rotor assembly 616 and the inner surface of the secondary motor stator assembly 614. One or more permanent magnets can be fixed to the outer surface of the secondary rotor assembly 616 so that the permanent magnets are affected by the magnetic field generated by the secondary motor stator assembly 614. The secondary rotor assembly 616 can be mounted inside the secondary motor stator assembly 614 on the common motor shaft 602.

[0063]

[0086] Figure 7 shows an isometric view of a third configuration of a radial-axial propulsion motor 700 according to one embodiment of the present invention. Figure 7 shows a primary rotor assembly 704 mounted on a common motor shaft 702. A primary stator assembly 712 surrounds the radial flux propulsion motor 700. As shown in Figure 7, the third configuration of the radial-axial propulsion motor includes a plurality of secondary motor stator assemblies 714, one of which can be seen in Figure 7. The primary rotor assembly 704 can be seen inside the primary stator assembly 712. The common motor shaft 702 can be seen emerging from a recess in the secondary motor stator assembly 714.

[0064]

[0087] Figure 8 shows an exemplary cross-sectional perspective view of a fourth configuration of a radial-axial propulsion motor 800 according to one embodiment of the present invention. In the fourth configuration, the primary motor may be a radial flux induction motor, and the secondary motors may include an axial flux permanent magnet motor and an axial flux induction motor. In the fourth configuration, the primary rotor assembly 804 may include a radial flux induction motor mounted on a common motor shaft 802. The advantages of the radial flux induction motor are described above with reference to the third configuration. The additional axial flux permanent magnet motor and axial flux induction motor increase the total torque generated by the radial-axial propulsion motor and allow for greater control of torque fluctuations on the common shaft compared to the first configuration of the radial-axial propulsion motor.

[0065]

[0088] Similar to Figure 6, this configuration integrates two secondary motors optimized for low-torque operation. Thus, this configuration can operate in a similar manner where the primary induction motor is de-excited and the secondary motors operate more efficiently. Additional advantages include a lower-cost secondary motor, as induction motors are typically less expensive than permanent magnet motors, as well as the elimination of the passive cogging torque present in permanent magnet motors. When stopped, the secondary motor in Figure 6 generates passive cogging torque and iron loss due to the "always-on" permanent magnets, while in Figure 8, the de-excited motor generates neither passive cogging torque nor passive iron loss.

[0066]

[0089] The primary rotor assembly 804 may include one or more coils. A first current can be passed through one or more coils to generate a magnetic field. The primary stator assembly 812 can be mounted on the inner surface of the circular RADAX motor frame. The primary stator assembly 812 may be installed such that an air gap exists between the primary rotor assembly 804 and the primary stator assembly 812. A second current can pass through the primary stator assembly 812 to generate a magnetic field. The magnetic field generated by the primary stator assembly 812 can influence the magnetic field generated by the primary rotor assembly 804, causing a radial force that rotates the common motor shaft 802.

[0067]

[0090] A RADAX motor frame may include two RADAX motor end walls. On one side of the RADAX motor, a secondary motor stator assembly 814 can be fixed along the inner portion of one of the two RADAX motor end walls. The secondary motor stator assembly 814 may include a circular stator assembly surrounding a common motor shaft 802. A third current can be applied to the secondary motor stator assembly 814 to generate a magnetic field. The secondary rotor assembly 816 can be fixed to the common motor shaft 802 such that a gap exists between the outer surface of the secondary rotor assembly 816 and the inner surface of the secondary motor stator assembly 814. One or more permanent magnets can be fixed to the outer surface of the secondary rotor assembly 816 so that the permanent magnets are affected by the magnetic field generated by the secondary motor stator assembly 814. The secondary rotor assembly 816 can be mounted inside the secondary motor stator assembly 814 on the common motor shaft 802.

[0068]

[0091] An axial flux induction motor can be installed on the second side of the RADAX motor. The secondary motor stator assembly 814 can be fixed along one inner portion of the two RADAX motor end walls. The secondary motor rotor assembly 818 may include an axial flux induction motor. The secondary motor rotor assembly 818 may include one or more coils. The secondary motor rotor assembly 818 can be fixed to the common motor shaft 802. A fourth current can be passed through one or more coils to generate a magnetic field. An air gap may exist between the secondary motor rotor assembly 818 and the secondary motor stator assembly 814. A fifth current can also pass through the secondary motor stator assembly 814 to generate a magnetic field. The magnetic field generated by the secondary motor stator assembly 814 may affect the magnetic field generated by the secondary motor rotor assembly 818, potentially creating a tangent that rotates the common motor shaft 802.

[0069]

[0092] Figure 9 shows an isometric view of a fourth configuration of a radial-axial propulsion motor 900 according to one embodiment of the present invention. Figure 9 shows a primary rotor assembly 904 mounted on a common motor shaft 902. A primary stator assembly 912 surrounds the radial flux propulsion motor 900. As shown in Figure 9, a third configuration of the radial-axial propulsion motor includes multiple secondary motor stator assemblies 914, one of which can be seen in Figure 9. The primary rotor assembly 904 can be seen inside the primary stator assembly 912. The common motor shaft 902 can be seen emerging from a recess in the secondary motor stator assembly 914.

[0070]

[0093] Figure 10 shows an exemplary cross-sectional perspective view of a fifth configuration of a radial-axial propulsion motor 1000 according to one embodiment of the present invention. In the fifth configuration, the primary motor can be a radial flux induction motor, and the secondary motor can include an axial flux permanent magnet motor and three axial flux induction motors. As described above for the fourth configuration, axial flux induction motors may be less expensive than axial flux permanent magnet motors of similar size.

[0071]

[0094] In this configuration, several low-cost induction motors are paired with high-efficiency axial flux permanent magnet motors. This leverages the high efficiency provided by the secondary permanent magnet motor for primary low-torque operation and the low-cost secondary induction motor for other low-torque operating points that do not require a primary radial flux motor. An additional advantage is the ability to passively generate power via the secondary permanent magnet motor while the primary induction motor is generating torque or while the common motor shaft is braking.

[0072]

[0095] In the fifth configuration, the primary rotor assembly 1004 may include a radial flux induction motor mounted on the common motor shaft 1002. The primary rotor assembly 1004 may include one or more coils. A first current can be passed through one or more coils to generate a magnetic field. The primary stator assembly 1012 may be mounted on the inner surface of a circular RADAX motor frame. The primary stator assembly 1012 may be installed such that an air gap exists between the primary rotor assembly 1004 and the primary stator assembly 1012. A second current can pass through the primary stator assembly 1012 to generate a magnetic field. The magnetic field generated by the primary stator assembly 1012 can influence the magnetic field generated by the primary rotor assembly 1004, causing a radial force that rotates the common motor shaft 1002.

[0073]

[0096] A RADAX motor frame may include two RADAX motor end walls. On one side of the RADAX motor, a secondary motor stator assembly 1014 can be fixed along the inner portion of one of the two RADAX motor end walls. The secondary motor stator assembly 1014 may include a circular stator assembly surrounding a common motor shaft 1002. Current can be applied to the secondary motor stator assembly 1014 to generate a magnetic field. The secondary rotor assembly 1016 can be fixed to the common motor shaft 1002 such that a gap exists between the outer surface of the secondary rotor assembly 1016 and the inner surface of the secondary motor stator assembly 1014. One or more permanent magnets can be fixed to the outer surface of the secondary rotor assembly 1016 so that the permanent magnets are affected by the magnetic field generated by the secondary motor stator assembly 1014. The secondary motor rotor assembly 1016 can be mounted inside the secondary motor stator assembly 1014 on the common motor shaft 1002.

[0074]

[0097] An axial flux induction motor can be installed on the same side as the axial flux permanent magnet motor described above. The secondary motor stator assembly 1014 can be fixed along one inner portion of the two RADAX motor end walls. The secondary motor rotor assembly 1018 may include an axial flux induction motor. The secondary motor rotor assembly 1018 may include one or more coils. The secondary motor rotor assembly 1018 can be fixed to the common motor shaft 1002. A third current can be passed through one or more coils to generate a magnetic field. An air gap may exist between the secondary motor rotor assembly 1018 and the secondary motor stator assembly 1014. A fourth current can also pass through the secondary motor stator assembly 1014 to generate a magnetic field. The magnetic field generated by the secondary motor stator assembly 1014 may affect the magnetic field generated by the secondary motor rotor assembly 1018, potentially creating a tangent that rotates the common motor shaft 1002.

[0075]

[0098] Two axial flux induction motors can be installed on the second side of the RADAX motor. The secondary motor stator assembly 1014 can be fixed along one inner portion of the end wall of the two RADAX motors. The secondary motor rotor assembly 1018 can include an axial flux induction motor. The secondary motor rotor assembly 1018 can include one or more coils. The secondary motor rotor assembly 1018 can be fixed to the common motor shaft 1002. A first current can be passed through one or more coils to generate a magnetic field. An air gap can exist between the secondary motor rotor assembly 1018 and the secondary motor stator assembly 1014. A second current can also pass through the secondary motor stator assembly 1014 to generate a magnetic field. The magnetic field generated by the secondary motor stator assembly 1014 can affect the magnetic field generated by the secondary motor rotor assembly 1018, potentially creating a tangent that rotates the common motor shaft 1002.

[0076]

[0099] Figure 11 shows an isometric view of a fifth configuration of a radial-axial propulsion motor 1100 according to one embodiment of the present invention. Figure 11 shows a primary rotor assembly 1104 mounted on a common motor shaft 1102. The primary stator assembly 1112 surrounds the radial flux propulsion motor 1100. As shown in Figure 11, the third configuration of the radial-axial propulsion motor includes a plurality of secondary motor stator assemblies 914, two of which can be seen in Figure 11. The primary rotor assembly 1104 can be seen inside the primary stator assembly 1112. The common motor shaft 1102 can be seen emerging from a recess in the secondary motor stator assembly 1114.

[0077]

[0100] Figure 12 shows an exemplary cross-sectional perspective view of a sixth configuration of a radial-axial propulsion motor 1200 according to one embodiment of the present invention. In the sixth configuration, the primary motor may include a radial flux induction motor, and the secondary motor may include an axial flux permanent magnet motor and a transverse flux motor. High torque density direct-drive electromechanical motors are highly desirable as electric vehicle traction motors. Direct-drive machines have high torque at low speeds and offer high reliability and low cost by eliminating mechanical gearboxes, which are typically less efficient. Transverse flux machines (TFMs) are inherently well-suited for direct-drive applications due to their high torque density. A distinctive feature of TFMs is their "ring" shaped windings that couple each stator core to the entire armature ampere-turn. As a result, high torque is achieved by increasing the number of poles without sacrificing electrical load.

[0078]

[0101] In this configuration, the RADAX is designed to accommodate different operating modes. When low speed and high torque are required, the secondary transverse flux motor and / or primary radial flux motor are activated. When the load torque requirement is reduced, the secondary permanent magnet motor is activated for low-load operation, improving the efficiency of the RADAX motor. This configuration can be used in applications with large disengagement torque requirements or large intermittent torque requirements, such as electric vehicles and aircraft.

[0079]

[0102] The primary rotor assembly 1204 may include a circular disc having an inner portion near the center of the circular disc and an outer portion along the circumference of the circular disc. The outer portion 1210 of the rotor assembly may be T-shaped and may include the rotor assembly surface. The primary rotor assembly 1204 can be mounted on the common motor shaft 1202 at its inner portion. Permanent magnets can be fixed on the outer portion 1210 on the rotor assembly surface at the T-shaped end of the rotor assembly 1204. The primary stator assembly 1212 can be mounted on the inner surface of the circular RADAX motor frame. The primary stator assembly 1212 can be installed such that an air gap exists between the primary rotor assembly 1204 and the primary stator assembly 1212. A first current can pass through the primary stator assembly 1212 to generate a magnetic field. The magnetic field generated by the primary stator assembly 1212 can affect the permanent magnets fixed to the surface of the primary rotor assembly 1204, causing a radial force that rotates the common motor shaft 1202.

[0080]

[0103] A transverse flux motor can be included on one side of the primary rotor assembly 1204. A secondary transverse flux stator assembly 1220 can be mounted on one side of the RADAX motor case. The transverse flux stator assembly 1220 may include several stator cores. Multiple coils pass through the stator core and generate a magnetic field when current is applied. The rotor can be positioned in the center of the stator, and one or more permanent magnets can be fixed to the edge of the rotor so that the permanent magnets pass through notches in the stator core. An air gap may exist between the permanent magnets and the stator core. A second current can pass through the secondary transverse flux stator assembly 1220 to generate a magnetic field. The magnetic field generated by the secondary transverse flux stator assembly 1220 can affect permanent magnets fixed to the secondary rotor assembly 1222, causing a lateral force that rotates the common motor shaft 1202.

[0081]

[0104] On the opposite side of the transverse flux motor, the secondary motor stator assembly 1214 can be fixed along the inner portion of the RADAX motor end wall. The secondary motor stator assembly 1214 may include a circular stator assembly surrounding the common motor shaft 1202. A third current can be applied to the circular stator assembly 1214 to generate a magnetic field. The secondary rotor assembly 1216 can be fixed to the common motor shaft 1202 such that a gap exists between the outer surface of the secondary rotor assembly 1216 and the inner surface of the secondary motor stator assembly 1214. One or more permanent magnets can be fixed to the outer surface of the secondary rotor assembly 1216 so that the permanent magnets are affected by the magnetic field generated by the secondary motor stator assembly 1214. The secondary rotor assembly 1216 can be mounted inside the secondary motor stator assembly on the common motor shaft 1202.

[0082]

[0105] Figure 13 shows an isometric view of a sixth configuration of a radial-axial propulsion motor 1300 according to one embodiment of the present invention. Figure 13 shows a primary rotor assembly 1304 mounted on a common motor shaft 1302. A primary stator assembly 1312 surrounds the radial flux propulsion motor 1300. As shown in Figure 13, a third configuration of the radial-axial propulsion motor may include a secondary transverse flux stator assembly 1220. The primary rotor assembly 1304 can be seen inside the primary stator assembly 1312. The common motor shaft 1302 can be seen emerging from a recess in the secondary transverse flux stator assembly 1320.

[0083]

[0106] Figure 14 shows an exemplary cross-sectional perspective view of a seventh configuration of a radial-axial propulsion motor 1400 according to one embodiment of the present invention. In the seventh configuration, the primary motor may include a radial flux induction motor, and the secondary device may include an axial flux permanent magnet motor and a planetary gearbox. Inside the motor frame, the primary rotor assembly 1404 can be mounted on a common motor shaft 1402.

[0084]

[0107] This configuration offers similar advantages to other RADAX configurations by adding a gearbox to the output. The integrated gearbox (planetary or other form) amplifies a common RADAX shaft torque or speed depending on the gear selection. Adding an integrated gear set allows for the use of lower torque motors in applications and creates a more compact RADAX solution.

[0085]

[0108] The primary rotor assembly 1404 may include a circular disk having an inner portion 1408 at the center of the circular disk, and an outer portion 1410 along the circumference of the circular disk. The outer portion 1410 of the primary rotor assembly 1404 may be T-shaped and may include a rotor assembly surface perpendicular to the surface of the circular disk. The primary rotor assembly 1404 can be mounted on the common motor shaft 1402 by the inner portion 1408 of the primary rotor assembly 1404. One or more permanent magnets can be fixed to the primary rotor assembly surface at the T-shaped end of the primary rotor assembly 1404. The primary stator assembly 1412 can be mounted on the inner surface of the circular RADAX motor frame. The primary stator assembly 1412 can be installed such that an air gap exists between the primary rotor assembly 1404 and the primary stator assembly 1412. A first current can pass through the primary stator assembly 1412 to generate a magnetic field. The magnetic field generated by the primary stator assembly 1412 can affect the permanent magnets fixed to the surface of the primary motor rotor, causing a radial force that rotates the common motor shaft 1402.

[0086]

[0109] In the seventh configuration of the radial-axial propulsion motor 1400 shown in Figure 14, a planetary gearbox 1424 is mounted on one side of the primary rotor assembly 1404. The planetary gearbox 1424 is a gearbox in which the input shaft and output shaft are aligned. The planetary gearbox 1424 is used to transmit maximum torque in the most compact form (known as torque density).

[0087]

[0110] On the opposite side of the planetary gearbox 1424, a secondary motor stator assembly 1414 can be fixed along the inner portion of the RADAX motor end wall. The secondary motor stator assembly 1414 may include a circular stator assembly surrounding the common motor shaft 1402. A first current can be applied to the circular stator assembly 1414 to generate a magnetic field. The secondary rotor assembly 1416 can be fixed to the common motor shaft 1402 such that a gap exists between the outer surface of the secondary rotor assembly 1416 and the inner surface of the secondary motor stator assembly 1414. One or more permanent magnets can be fixed to the outer surface of the secondary rotor assembly 1416 so that the permanent magnets are affected by the magnetic field generated by the secondary motor stator assembly 1414. The secondary rotor assembly 1416 can be mounted inside the secondary motor stator assembly on the common motor shaft 1402.

[0088]

[0111] Figure 15 shows an isometric view of a seventh configuration of a radial-axial propulsion motor 1500 according to one embodiment of the present invention. Figure 15 shows a primary rotor assembly 1504 mounted on a common motor shaft 1502. A primary stator assembly 1512 surrounds the radial flux propulsion motor 1500. As shown in Figure 15, the seventh configuration of the radial-axial propulsion motor may include a planetary gearbox 1424. The primary rotor assembly 1504 can be seen inside the primary stator assembly 1512. The common motor shaft 1502 can be seen emerging from a recess in the planetary gearbox 1524.

[0089]

[0112] Figure 16 shows a torque-to-electrical angle plot 1600 for a first state of a radial-axial propulsion motor, including a radial flux induction primary motor and an axial flux permanent magnet motor, according to one embodiment of the present invention. Figure 16 shows a reference radial flux torque-to-electrical angle (degrees) plot 1602 for a radial flux propulsion motor similar to the radial flux induction motor of a fourth configuration shown in Figure 6. As shown in Figure 16, the torque generated by the axial flux propulsion motor can be combined with the torque generated by the radial flux induction primary motor to produce an integrated torque 1606 associated with the radial-axial propulsion motor. The integrated torque from the axial flux propulsion motor can increase the steady-state integrated torque 1606. In some implementations, the increase in integrated torque 1606 can be about 10%. Based on the dq-axis current of the axial flux propulsion motor(s), the integrated torque may be transient and may result in oscillations (e.g., about 2 foot-pounds). Torque oscillations are undesirable because they can result in increased vibrations. Increased vibration can enhance the sonic characteristics of the vessel, making the ship more detectable and identifiable. As shown in Figure 17, the q-axis and d-axis can be adjusted to reduce these torque vibrations and further generate and increase average torque across only the primary radial motor.

[0090]

[0113] Figure 17 shows a plot of torque versus electrical angle 1700 for a second state of radial-axial propulsion motors, including radial flux induction primary motors and axial flux permanent magnet motors. Figure 17 shows a plot of reference radial flux torque versus electrical angle (degrees) 1702 for radial flux induction propulsion motors. As shown in Figure 17, an axial flux propulsion motor can combine with the radial flux force generated by a radial flux induction motor to produce an integrated torque 1706. The torque from the axial flux propulsion motor can increase the steady-state integrated RADAX torque 1706. In some implementations, the increase in integrated RADAX torque 1706 can be about 10%. Figure 17 shows that by adjusting the d-axis and q-axis currents of an axial flux propulsion motor (maybe more), the instability of the integrated torque can be reduced from 2 foot-pounds to about 0.3 foot-pounds, as shown in Figure 16, while still providing an average integrated torque increase of about 2 foot-pounds (about 10%).

[0091]

[0114] Figure 18 shows a torque-to-electrical angle plot for a third state of a radial-axial propulsion motor, including a radial flux induction primary motor and an axial flux permanent magnet motor. Figure 18 shows a plot 1802 of the reference radial flux torque-to-electrical angle (degrees) for a radial propulsion motor. As shown in Figure 18, the axial flux propulsion motor can combine with the radial flux force to produce an integrated torque 1804. The integrated torque from the axial flux propulsion motor can increase the steady-state integrated RADAX torque 1806. Further adjustment of the d-axis and q-axis currents can increase the integrated torque 1806 by approximately 10%. However, due to the d-axis and q-axis currents of the axial flux propulsion motor(s), the integrated torque may be non-steady and may result in oscillations (e.g., approximately 3 foot-pounds). Torque fluctuations can be undesirable, as described above. Therefore, by independently controlling the radial motor and the axial motor, a means can be provided to reduce integrated torque fluctuations.

[0092]

[0115] Figure 19 shows a plot of torque versus electrical angle for a fourth state of radial-axial propulsion motors, including radial flux induction primary motors and axial flux permanent magnet motors. Figure 19 shows a plot of reference radial flux torque versus electrical angle (degrees) for a radial propulsion motor. As shown in Figure 19, the axial flux propulsion motor can combine with the radial flux force to produce an integrated torque. As shown in Figure 19, the contribution of the axial flux propulsion motor can be negative due to dq phase rotation changes or because the integrated axial flux propulsion motor is used as a generator. The integrated torque from the axial flux propulsion motor can reduce the steady-state combined RADAX torque. In some implementations, the reduction in combined RADAX torque can be about 10%. Figure 19 shows that the instability of the combined torque can be reduced by adjusting the dq axis current of the axial flux propulsion motor(s), and as a result, the oscillation of the combined torque can be reduced (e.g., about 0.3 foot-pounds). Figure 19 illustrates another advantage of radial-axial flux motors for fine-tuning torque output and reducing torque fluctuations.

[0093]

[0116] Figure 20 shows a force plot over time for a first state of a radial-axial propulsion motor, which includes a radial flux induction propulsion motor for the primary motor and two axial flux permanent magnet motors for the secondary motors. Figure 20 shows a plot of reference radial flux torque against time 2002 for the radial flux induction propulsion motor. The first axial flux torque 2004 from the first axial flux propulsion motor can be combined with the second axial flux torque 2006 from the second axial flux propulsion motor. In the first dq state of the first and second axial flux propulsion motors, the first axial flux torque 2004 and the second axial flux torque 2006 appear to be in phase. The radial flux torque 2002 also appears to be in phase with the first axial flux torque 2004 and the second axial flux torque 2006. As shown in Figure 20, the axial flux propulsion motor can combine with the radial flux torque 2002 to generate an integrated torque 2008. The integrated torque 2008 also appears to be in phase with the radial flux torque 2002, the first axial flux torque 2004, and the second axial flux torque 2006.

[0094]

[0117] Figure 21 shows a force plot over time for a second state of a radial-axial propulsion motor, which includes a radial flux induction motor for the primary motor and two axial flux permanent magnet motors for the secondary motors. Figure 21 shows a plot 2102 of the reference radial flux torque against time for the radial flux induction propulsion motor. The first axial flux torque 2104 from the first axial flux propulsion motor can be combined with the second axial flux torque 2106 from the second axial flux propulsion motor. In the second dq state of the first and second axial flux propulsion motors, the first axial flux torque 2104 and the second axial flux torque 2106 appear to be 180 degrees out of phase. The radial flux torque 2102 is also in phase with the first axial flux torque 2104, but appears to be 180 degrees out of phase with the second axial flux torque 2106. As shown in Figure 21, the axial flux propulsion motor can combine with the radial flux torque 2102 to generate an integrated torque 2108. The additional torque from the first axial flux torque 2104 can be offset by the second axial flux torque 2106. Therefore, the integrated torque 2108 is not significantly different from the radial flux torque 2104.

[0095]

[0118] Figure 22 shows a force plot over time for a third state of a radial-axial propulsion motor, which includes a radial flux induction motor for the primary motor and two axial flux permanent magnet motors for the secondary motors. Figure 22 shows a plot of reference radial flux torque versus time for the radial flux induction propulsion motor. The first axial flux torque 2204 from the first axial flux propulsion motor can be combined with the second axial flux torque 2206 from the second axial flux propulsion motor. In the third dq state of the first and second axial flux propulsion motors, the first axial flux torque 2204 and the second axial flux torque 2206 appear to be in phase. The first axial flux torque 2204 appears to produce a positive contribution, while the second axial flux torque 2206 appears to produce a negative contribution. The radial flux torque 2202 also appears to be 180 degrees out of phase with the first axial flux torque 2204 and the second axial flux torque 2206. As shown in Figure 22, the axial flux propulsion motor can combine the radial flux torque 2202 with the radial flux torque 2202 to generate an integrated torque 2208. The integrated torque 2208 can reduce or eliminate the unsteady force of the integrated torque 2208 caused by the dq current control of the integrated axial flux propulsion motor. However, the force on the integrated torque 2208 is not significantly different from the average torque force of the radial flux torque 2202.

[0096]

[0119] Figure 23 shows a simplified electric propulsion system 2300 for a vehicle, ship, or aircraft. The electric propulsion system 2300 may include a radial-axial motor 2302. The radial-axial motor 2302 may include any combination of primary and secondary motors as described herein. For example, Figure 23 shows a primary motor 2304 and two secondary axial magnetic flux propulsion motors 2306. The primary motor 2304 and the secondary motors 2306 can drive a common shaft 2308. In some embodiments, the common shaft 2308 can rotate a propeller 2310. The electric propulsion system 2300 may receive alternating current from a main power distribution system. A controller 2312 can change the amount of current applied to the motor and the dq state. An AC / DC converter 2314 or inverter 2316 can be used to change the current from alternating current to direct current, or from direct current to alternating current, respectively.

[0097]

[0120] Figure 24 is a flowchart of an exemplary process 2400 for generating torque on a shaft for a propulsion system (e.g., a hybrid radial-axial motor). In some implementations, one or more process blocks in Figure 24 may be performed by an electromechanical device. In some implementations, one or more process blocks in Figure 24 may be performed by a separate device or group of devices, either separate from or including an electromechanical device.

[0098]

[0121] The method includes the step (2410) of receiving a first current in a radial motor having rotor arms mounted on a shaft. As an example, the first current includes a first set of d-axis currents and q-axis currents applied to the radial motor. The radial motor is positioned within a housing. The first current can be an alternating current passing through a primary rotor stator. The first current can be controlled independently using a controller. The amplitude, cycle, phase, frequency, peak-to-peak voltage, and root mean square of the voltage of the second current can be controlled.

[0099]

[0122] The method includes the step (2420) of generating a radial magnetic flux in a first direction in response to a first current. When an alternating current passes through the coils of a radial motor, a magnetic field or magnetic flux can be generated. The radial magnetic flux extends radially with respect to the direction of the rotor shaft.

[0100]

[0123] The method also includes the step (2430) of generating a first torque in the rotor arm based on a radial magnetic flux interacting with a first magnetic unit. The first magnetic unit may be a permanent magnet. The first magnetic unit may be an induction motor. In various embodiments, the rotor motor includes a radial arm. The radial arm may include one or more permanent magnets on its surface. The permanent magnets generate a magnetic field in response to the magnetic field of the radial stator. This reaction generates a torque in the rotor arm, which in turn generates a torque in the common rotor shaft.

[0101]

[0124] In various embodiments, the radial motor can include an induction motor. Similar to a rotary stator, an induction motor can generate a magnetic field by applying an alternating current to a series of coils in an induction motor rotor. The induction motor rotor can generate a magnetic field that responds to the magnetic field of the radial stator. This reaction generates torque in the rotor arms, which in turn generates torque in the common rotor shaft.

[0102]

[0125] The method also includes the step (2440) of receiving a second current in an axial motor. As an example, the second current includes a second set of d-axis and q-axis currents applied to a radial motor. The axial motor is positioned within a housing. The second current can be an alternating current passing through a secondary motor stator. The second current can be controlled independently using a controller. The amplitude, cycle, phase, frequency, peak-to-peak voltage, and root mean square of the voltage of the second current can be controlled.

[0103]

[0126] The method also includes the step (2450) of generating an axial magnetic flux in a second direction. When an alternating current passes through the coils of an axial motor, a magnetic field or axial magnetic flux can be generated.

[0104]

[0127] The method also includes the step (2460) of generating a second torque in the rotor arm based on an axial magnetic flux interacting with a second magnetic unit. The second magnetic unit may be a permanent magnet. The second magnetic unit may be an induction motor. In various embodiments, the secondary motor includes a rotor arm. The rotor arm may include one or more permanent magnets on the surface of the axial rotor arm. The permanent magnets generate a magnetic field in response to the magnetic field of the axial stator. This reaction generates a torque in the axial rotor arm, which in turn generates a torque in the common rotor shaft.

[0105]

[0128] In various embodiments, the axial motor can include an induction motor. Similar to a rotary stator, an induction motor can generate a magnetic field by applying an alternating current to a series of coils in an induction motor rotor. The induction motor rotor can generate a magnetic field that responds to the magnetic field of the axial stator. This reaction generates torque in the axial rotor arms, which in turn generates torque in the common rotor shaft.

[0106]

[0129] In some implementations, radial and axial motors are positioned within a housing to reduce cross-magnetic flux from either the radial or axial motor.

[0107]

[0130] Process 2400 may include additional implementations, such as any single implementation or any combination of implementations relating to one or more other processes described below and / or elsewhere in this specification. It should be understood that the specific steps shown in Figure 24 provide specific techniques for hybrid radial-axial motors according to various embodiments of this disclosure. According to alternative embodiments, steps may also be performed in a different order. For example, alternative embodiments of this disclosure may perform the above steps in a different order. Furthermore, the individual steps shown in Figure 24 may include multiple substeps that can be performed in various orders as appropriate to the individual steps. Additionally, additional steps may be added or removed depending on the specific application. Many variations, modifications, and alternatives will be recognized by those skilled in the art.

[0108]

[0131] In various embodiments, the first torque is characterized by a first vibration amplitude, the second torque is characterized by a second vibration amplitude, and the sum of the first and second torques is characterized by an integrated vibration amplitude smaller than both the first and second vibration amplitudes.

[0109]

[0132] In various embodiments, the method further includes the steps of operating the propulsion system in boost mode by setting a first current to a first maximum value and setting a second current to a second maximum value.

[0110]

[0133] In various embodiments, the method further includes the step of operating the propulsion system in coast mode by selectively reducing or de-exciting a first or second current, or a combination thereof.

[0111]

[0134] In some implementations, process 2400 may include the step of receiving a third current in a transverse flux motor that generates a transverse flux in a third direction, the transverse flux affecting a third magnetic unit to generate a third torque in a rotor arm mounted on a shaft.

[0112]

[0135] Figure 24 shows exemplary steps of process 2400, but in some implementations, process 2400 may include additional steps, fewer steps, different steps, or steps in different configurations than those shown in Figure 24. Additionally or alternatively, two or more steps of process 2400 may be executed in parallel.

[0113]

[0136] The methods, systems, and devices described above are examples. In various configurations, various steps and components may be omitted, replaced, or added as needed. For example, in alternative configurations, the methods may be performed in a different order than described, and / or various steps may be added, omitted, and / or combined. Also, features described for a particular configuration may be combined in various other configurations. Different aspects and elements of a configuration may be combined in similar ways. Furthermore, because technology is evolving, many of the elements are examples and do not limit the scope of this disclosure or claims.

[0114]

[0137] Certain details are described in order to provide a complete understanding of the configuration examples (including implementation forms). However, the configuration may be carried out without these specific details. For example, well-known circuits, processes, algorithms, structures, and techniques are shown without unnecessary details to avoid obscuring the configuration. This description provides only configuration examples and does not limit the claims, applicability, or configuration. Rather, the foregoing description of the configuration will provide a practical description for carrying out the described techniques for those skilled in the art. Various modifications can be made to the function and arrangement of the elements without departing from the spirit or scope of this disclosure.

[0115]

[0138] Furthermore, the configuration may be described as a process shown as a flow chart or block diagram. Each may describe its operation as a sequential process, but many operations can be performed in parallel or simultaneously. In addition, the order of operations may be rearranged. The process may have additional steps not included in the diagram. Furthermore, examples of methods may be implemented by hardware, software, firmware, middleware, microcode, hardware description language, or any combination thereof. If implemented in software, firmware, middleware, or microcode, the program code or code segments for performing the required tasks may be stored in a non-temporary computer-readable medium such as a storage medium. The processor may perform the described tasks.

[0116]

[0139] While several exemplary configurations have been described, various modifications, alternative configurations, and equivalents can be used without departing from the spirit of this disclosure. For example, the elements described above may be components of a larger system, and other rules may take precedence over the application of this disclosure, or the application may be modified. Also, several steps may be taken before, during, or after considering the elements described above.

Claims

1. Housing and A radial motor disposed inside the housing, wherein the radial motor is configured to generate a radial magnetic flux in a first direction, and the radial magnetic flux affects a first magnetic unit to generate a first torque on a rotor arm attached to a shaft, An axial motor disposed inside the housing, wherein the axial motor is configured to generate an axial magnetic flux in a second direction, and the axial magnetic flux affects a second magnetic unit to generate a second torque in the rotor arm attached to the shaft, A controller or load configured to independently control the first torque and the second torque, An electrical machine equipped with the necessary components.

2. The electromachine according to claim 1, wherein the controller controls the d-axis current and q-axis current applied to at least one of the radial motor, the axial motor, or a combination thereof, in order to reduce torque vibration on the shaft.

3. The electric machine according to claim 1, wherein the radial motor or the axial motor is replaced by a gear set.

4. The electrical machine according to claim 1, wherein the radial motor includes an induction motor.

5. The electrical machine according to claim 1, wherein the radial motor is configured as a wound-field synchronous motor.

6. The electrical machine according to claim 1, wherein the radial motor is composed of a DC motor.

7. The electrical machine according to claim 1, wherein the radial motor is composed of a universal motor.

8. The electrical machine according to claim 1, wherein the radial motor is composed of a reluctance motor.

9. The electric machine according to claim 1, further comprising two or more axial motors within the housing.

10. The electric machine according to claim 1, wherein the axial motor includes an induction motor.

11. The electric machine according to claim 1, further comprising a transverse flux motor in the housing, the transverse flux motor generating a transverse flux in a third direction, the transverse flux influencing a third magnetic unit to generate a third torque in the rotor arm attached to the shaft.

12. Housing and A radial motor disposed within the housing, wherein the radial motor is configured to generate a radial magnetic flux in a first direction, and the radial magnetic flux affects a first magnetic unit to generate a first torque on a rotor arm attached to a shaft, An axial motor disposed within the housing, wherein the axial motor is configured to generate an axial magnetic flux in a second direction, and the axial magnetic flux affects a second magnetic unit to generate a second torque in the rotor arm attached to the shaft, A controller configured to independently control the first torque and the second torque, A propulsion system equipped with [the necessary components].

13. The propulsion system according to claim 12, wherein the controller controls d-axis currents and q-axis currents applied to at least one of the radial motor, the axial motor, or a combination thereof, in order to reduce or amplify torque vibrations on the shaft.

14. The propulsion system according to claim 12, wherein the radial motor or the axial motor is replaced by a gear set.

15. The propulsion system according to claim 12, wherein the radial motor includes an induction motor.

16. The propulsion system according to claim 12, wherein the axial motor includes an induction motor.

17. The propulsion system according to claim 12, further comprising two or more axial motors within the housing.

18. The propulsion system according to claim 12, wherein the propulsion system further comprises a transverse flux motor in the housing, the transverse flux motor generates a transverse flux in a third direction, and the transverse flux affects a third magnetic unit to generate a third torque in the rotor arm attached to the shaft.

19. A method for generating torque in a shaft for a propulsion system, wherein the method is A step of receiving a first current in a radial motor having a rotor arm attached to the shaft, wherein the radial motor is positioned within a housing, A step of generating a radial magnetic flux in a first direction in response to the first current, A step of generating a first torque in the rotor arm based on the radial magnetic flux interacting with the first magnetic unit, A step of receiving a second current with an axial motor, wherein the axial motor is positioned within the housing, A step of generating an axial magnetic flux in a second direction, A step of generating a second torque in the rotor arm based on the axial magnetic flux interacting with the second magnetic unit. Methods that include...

20. The method according to claim 19, wherein the first current includes a first set of d-axis currents and q-axis currents applied to the radial motor.

21. The method according to claim 19, wherein the second current includes a second set of d-axis currents and q-axis currents applied to the axial motor.

22. The first torque is characterized by the first vibration amplitude, The second torque is characterized by the second vibration amplitude, The sum of the first torque and the second torque is characterized by an integrated vibration amplitude that is smaller than both the first vibration amplitude and the second vibration amplitude. The method according to claim 19.

23. The steps include setting the first current to a first maximum value, The steps include setting the second current to a second maximum value, The step of operating the propulsion system in boost mode by The method according to claim 19, further comprising:

24. Selectively reducing or de-exciting the first current or the second current, or a combination thereof. The method according to claim 19, further comprising the step of operating the propulsion system in coast mode.

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