MAGNET-ASSISTED WINDED ROTOR FOR ELECTRIC MOTOR

Abstract

The aspects of this disclosure relate to an electric motor comprising a rotor with both permanent magnets and operable coils. The rotor's coils can be operated to generate a temporary magnetic field that complements the permanent magnetic field of the permanent magnets. Accordingly, the magnitude of the torque delivered by the rotor can be controlled as required by operating the rotor's coils.

Description

INTRODUCTION

[0001] The present disclosure relates generally to the fields of automotive, manufacturing, and industrial equipment. More specifically, the present disclosure relates to an electric motor having a magnetically assisted wound rotor. SUMMARY

[0002] This description generally relates to an electric motor including a rotor with permanent magnets and operable coils. The coils of the rotor can be operated to generate a temporary magnetic field that supplements the magnetic field of the permanent magnets. Accordingly, the amount of torque delivered by the rotor can be controlled as needed by operating the coils of both the stator and the rotor.

[0003] According to one or more aspects of the disclosure, a rotor for an electric motor includes a body configured to rotate about a central axis; permanent magnets within the body and circumferentially spaced apart about the central axis; and rotor coils within the body, each of the rotor coils forming winding segments circumferentially positioned between a corresponding adjacent pair of the permanent magnets.

[0004] According to one or more aspects of the disclosure, a motor includes a stator having stator coils configured to generate a rotating magnetic field; and a rotor configured to rotate about a central axis, comprising: permanent magnets circumferentially spaced from one another about the central axis, wherein circumferentially adjacent ones of the permanent magnets generate different permanent magnetic fields with respect to the central axis; and rotor coils forming winding segments, wherein each group of the winding segments circumferentially located between a corresponding adjacent pair of the permanent magnets is configured to receive a current and generate a temporary magnetic field that complements the different permanent magnetic fields of the corresponding adjacent pair of the permanent magnets.

[0005] According to one or more aspects of the disclosure, a method includes operating stator coils of a stator to generate a rotating magnetic field extending through a rotor comprising permanent magnets and rotor coils, wherein the permanent magnets of the rotor generate permanent magnetic fields; determining the torque demand; and, if the torque demand is above a threshold, operating the rotor coils of the rotor to generate temporary magnetic fields that supplement the permanent magnetic fields of the permanent magnets. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Certain features of the subject technology are set forth in the appended claims. However, for illustrative purposes, several embodiments of the subject technology are set forth in the following figures. Fig. 1 illustrates a perspective cut-away view of an exemplary electric motor according to one or more implementations of the subject technology. Fig. Figure 2 illustrates a sectional view of a portion of the electric motor of Fig. 1 according to one or more implementations of the subject technology. Fig. 3 illustrates a cross-sectional view of a portion of a rotor according to one or more implementations of the subject technology. Fig. 4 illustrates a cross-sectional view of a portion of a rotor according to one or more implementations of the subject technology. Fig. 5 illustrates a cross-sectional view of a portion of an engine according to one or more implementations of the subject technology. Fig. Figure 6 illustrates a sectional view of the portion of the engine of Fig. 5 according to one or more implementations of the subject technology. Fig. 7 illustrates a cross-sectional view of a portion of an engine according to one or more implementations of the subject technology. Fig. Figure 8 illustrates a sectional view of the portion of the engine of Fig. 7 according to one or more implementations of the subject technology. Fig. 9 illustrates a cross-sectional view of a portion of an engine according to one or more implementations of the subject technology. Fig. Figure 10 illustrates a sectional view of the portion of the engine of Fig. 9 according to one or more implementations of the subject technology. Fig. 11 illustrates a cross-sectional view of a portion of an engine according to one or more implementations of the subject technology. Fig. Figure 12 illustrates a sectional view of the portion of the engine of Fig. 11 according to one or more implementations of the subject technology. Fig. Figure 13 illustrates a graph of motor torque output at various rotor winding activity levels according to one or more implementations of the subject technology. Fig. 14 illustrates a flowchart of an example process for operating an electric motor according to one or more implementations of the subject technology. Fig. Figure 15 illustrates an electronic system that may implement one or more implementations of the subject technology. DETAILED DESCRIPTION

[0007] The following detailed description is intended as a description of various configurations of the present technology and is not intended to represent the only configurations in which the present technology may be practiced. The accompanying drawings are incorporated herein and form a part of the detailed description. The detailed description includes specific details for the purpose of providing a thorough understanding of the subject technology. However, the present technology is not limited to the specific details set forth herein and may be practiced using one or more other implementations. In one or more implementations, structures and components are shown in block diagram form to avoid obscuring the concepts of the present technology.

[0008] This description generally relates to an electric motor including a rotor with permanent magnets and operable coils. The coils of the rotor can be operated to generate a temporary magnetic field that supplements the permanent magnetic field of the permanent magnets. Accordingly, the amount of torque delivered by the rotor can be controlled as needed by operating the coils of both the stator and the rotor.

[0009] Permanent magnets, such as heavy rare earth (HRE) magnets, can be expensive, particularly due to supply and demand constraints. As the supply of such permanent magnets is limited and demand increases, costs can also increase over time. Accordingly, it can be advantageous to provide a machine with features that reduce dependence on permanent magnets. Furthermore, by providing wound rotor windings with the rotor of an electric motor, performance can be controlled to meet power requirements despite a reduction in permanent magnets.

[0010] Accordingly, electric motors such as those described herein can provide high-performance characteristics while using fewer and / or smaller magnets. Such an electric motor can also feature flexible and adaptive control parameters that allow operating conditions to be adapted to the requirements. Particularly at lower torque requirements, the stator and / or rotor excitations can be controlled to maximize the efficiency of the electric motor.

[0011] In certain embodiments, the motor described herein may include features of a synchronous electric motor. However, it should be understood that one or more features of the present disclosure may apply to a variety of motor types, including synchronous electric motors, permanent magnet synchronous electric motors (PMSMs), line-start synchronous motors (LSSMs), line-start permanent magnet motors (LSPMMs), and the like.

[0012] Referring to Fig. 1, a motor may include a stator and a rotor to provide rotational power to a shaft. Fig. 1 is a partial perspective view of a motor 10 having a stator 110 and a rotor 150.

[0013] In some embodiments, as in Fig. 1, a motor 10 may include a generally cylindrical rotor shaft 12 concentrically surrounded by a cylindrical rotor 150. As used herein, "cylindrical" and "annulus" refer to structures having a generally circular inner cross-sectional shape and a likely approximately circular outer cross-sectional shape, although this outer cross-sectional shape may vary somewhat, including flat or irregular portions. The rotor shaft 12 and the rotor 150 are configured to rotate together, possibly at high speed (RPM), concentrically about a common central axis 20. The rotor 150 may be made of electrical steel. The rotor shaft 12 may be made of steel and / or another possible metal or metal alloy.

[0014] The motor 10 may include a stator 110 with stator coils 120 configured to generate a rotating magnetic field. The rotating magnetic field may be generated by passing multiphase currents through the stator coils 120. The stator coils 120 may form segments of their windings distributed around the rotor 150. As shown in Fig. 1, the stator coils 120 may, for example, form segments that each extend in a direction generally parallel to the central axis 20 of the rotor 150. The rotating magnetic field generated by the stator 110 may rotate about the central axis 20 of the rotor 150. Neither the stator 110 nor the stator coils 120 need to move to generate the rotating magnetic field. The coils may, for example, be operated with an alternating current, with different segments thereof having a different current direction and / or current strength at a given time. Since the current direction and / or current strength for each segment of the stator coils 120 changes over time, the magnetic field generated near it may change accordingly. Accordingly, the resulting magnetic field may be described as a standing magnetic field (e.g.,with alternating magnetic field directions extending circumferentially around the central axis 20) that rotates about the central axis 20. The rotating magnetic field may further extend through the rotor 150, which may include permanent magnets 160 and rotor coils 170. The rotating magnetic field generated by the stator 110 may magnetically interact with such components of the rotor 150 to cause rotation of the rotor 150 about the central axis 20.

[0015] End windings of the stator coils 120 (e.g., crown end windings and / or weld end windings) of the stator 110 may be made of a conductive material, such as copper or another suitable metal or material. The end windings of the stator coils 120 may extend axially beyond the rotor 150 and / or concentrically surround the rotor 150. The end windings of the stator coils 120 are connected in parallel and / or in series to form a winding set with multi-phase terminals operatively connected to a control device, such as a processing unit of an electronic system, described further herein.

[0016] The rotor shaft 12 and / or the rotor 150 can be rotated using a first bearing assembly 25 disposed at the first end of the rotor shaft 12 and a second bearing assembly 27 disposed at the second end of the rotor shaft 12. Thus, the rotor 150 and / or the rotor shaft 12 can be rotated about the central axis 20 when responding to the rotating magnetic field generated by the stator 110. The rotor shaft 12 can accordingly provide a torque output. Such an output can be detected, for example, by a sensor of an electronic system described further herein.

[0017] The rotor coils 170 may form winding segments 172 of their windings that extend within the rotor 150. As shown in Fig. 1, the rotor coils 170 may, for example, form winding segments 172 that each extend in a direction generally parallel to the central axis 20 of the rotor 150. Additionally or alternatively, the winding segments 172 may extend longitudinally in a direction generally parallel to the segments of the stator coils 120. Each winding segment 172 may extend to or toward one or both of the longitudinal terminal ends of the rotor 150. For example, a particular winding segment 172 may extend longitudinally within a body of the rotor 150 and be connected to another winding segment 172 at a circumferentially adjacent pole of the rotor 150. Thus, the winding segments 172 can form windings that extend both parallel to the central axis 20 and transverse to the central axis 20 to form one or more loops.One or more end windings 174 may be provided at one or more ends of the rotor 150. Each of the end windings 174 of the rotor coils 170 may be operatively connected to a control device, such as a processing unit of an electronic system described further herein. In some embodiments, the end windings 174 may be connected to a power source via one or more brushes (not shown) so that the rotor 150 and the rotor coils 170 can rotate while the power source and / or the control circuitry supplies energy (e.g., electrical current) without rotating. Such brushes may further supply a generally uniform current to the rotor coils 170 so that the resulting temporary magnetic field can be maintained as needed during rotation of the rotor 150. Accordingly, the end windings 174 may be connected in such a manner (e.g.,with brushes) which enables rotation and direct current (DC) through the rotor coils 170.

[0018] Now referring to Fig. 2, a stator and a rotor can cooperate to provide rotational power. While Fig. While Figure 2 shows a portion of an engine 10, it should be understood that the portion shown may be a portion of a pattern that repeats circumferentially around a central axis to form continuous cylindrical structures. The pattern may repeat any number of cycles, so the illustrated example is not limited to the arrangement shown.

[0019] In some embodiments, as in Fig. 2, a stator 110 may include a stator body 112 and stator coils 120. The stator coils 120 and / or segments thereof may be positioned in stator coil chambers 126 formed in the stator body 112. The stator coil chambers 126 may form openings 128 on a radially inner side of the stator body 112 facing the rotor 150. The openings 128 may direct the magnetic fields generated by the stator coils 120 toward the rotor 150. The magnetic fields may be shaped at least in part by the geometry of the stator body 112.

[0020] In some embodiments, as in Fig. 2, a rotor 150 may include a rotor body 152, the permanent magnets 160, and the rotor coils 170. In some embodiments, the permanent magnets 160 may be positioned within magnet chambers 166 formed within the rotor body 152. The rotor body 152 defines cover portions 154, each radially disposed between a corresponding one of the plurality of magnet chambers 166 and a radially outermost side of the rotor 150. The cover portions 154 may hold the permanent magnets 160 in place while the rotor 150 rotates. The magnet chambers 166 may be distributed such that the permanent magnets 160 may be circumferentially spaced from each other and around the central axis.

[0021] In some embodiments, the rotor coils 170 and / or segments thereof may be positioned in rotor coil chambers 156 formed in the rotor body 152. The rotor coil chambers 156 may form openings 158 on a radially outer side of the rotor body 152 facing the stator 110. For example, the rotor body 152 may define the openings 158 such that each opening 158 is radially disposed between a corresponding one of the plurality of coil chambers 156 and a radially outermost side of the rotor 150. The openings 158 may direct the magnetic fields generated by the rotor coils 170 toward the stator 110. The magnetic fields may be shaped at least in part by the geometry of the rotor body 152.

[0022] As described herein, the stator coils 120 may be operated to generate a rotating magnetic field. The stator coils 120 may, for example, be operated with alternating current, with different segments thereof having a different current direction and / or current intensity at a given time. As the current direction and / or current intensity for each segment of the stator coils 120 changes over time, the magnetic field generated near it may change accordingly. The rotating magnetic field may extend through the rotor 150 to magnetically couple with the fields generated by the permanent magnets 160 and / or the rotor coils 170. The rotating magnetic field generated by the stator 110 may magnetically interact with such components of the rotor 150 to cause rotation of the rotor 150.

[0023] Now referring to Fig. 3, it is clear that the permanent magnets 160 can be provided in any arrangement, position, orientation, and / or number. For example, the permanent magnets 160 can have different sizes to fit into the magnetic chambers 166 of the rotor 150 and thus reduce the electromagnetic restoring forces. In some embodiments, as shown in Fig. 3, each magnetic chamber 166 may include a plurality of permanent magnets 160. A group of permanent magnets 160 within one of the plurality of magnetic chambers 166 may be circumferentially offset from one another within the corresponding magnetic chamber 166. Additionally or alternatively, the permanent magnets 160 within a particular magnetic chamber 166 and / or within different magnetic chambers 166 may have different sizes, shapes, materials, magnetic properties, and the like.

[0024] While one magnetic chamber 166 is shown circumferentially between a given pair of circumferentially adjacent rotor coils 170, any number of magnetic chambers 166 and / or permanent magnets may be provided between a pair of circumferentially adjacent rotor coils 170.

[0025] Now referring to Fig. 4, the rotor coils 170 may be arranged to generate temporary magnetic fields. As in Fig. 4, the rotor coils 170 may each include one or more winding segments 172 grouped within a corresponding one of the coil chambers 156 defined by the rotor body 152. For example, the rotor coils 170A and 170B may each form a plurality of winding segments 172A and 172B, respectively, circumferentially positioned between a corresponding adjacent pair of the permanent magnets 160. In another example, the winding segments 172A within a given coil chamber 156 may each be connected to a corresponding one of the winding segments 172A within an adjacent coil chamber 156 to form loops having a number of turns (N), thereby forming a rotor coil 170A having N turns extending across the adjacent pair of coil chambers 156. Such a rotor coil 170A may further extend around and / or in proximity to a corresponding one of the magnets 160. As shown in Fig. 4, first winding segments 172A of the first rotor coil 170A may extend longitudinally within each of a corresponding pair of coil chambers 156 of the rotor 150 and may be connected to other first winding segments 172A of the same first rotor coil 170A in another coil chamber 156 on a circumferentially adjacent permanent magnet 160. Another of the winding segments 172A of a rotor coil 170A may optionally be connected to another winding segment 172B of an adjacent rotor coil 170B. Thus, each rotor coil 170A or 170B may be formed from constituent segments (e.g., 172A and 172B, respectively) that wind in loops, spirals, and / or helices to circumferentially opposite sides of the corresponding permanent magnet 160. Furthermore, the coil segments can be arranged on different (e.g.Circumferentially adjacent) sides of a given permanent magnet 160 can supply current in opposite directions, such as opposite directions parallel to the central axis. Such flow can enable the generation of temporary magnetic fields that complement the permanent magnetic fields generated by the permanent magnets 160.

[0026] While in some embodiments, each of the rotor coils 170 (e.g., the first rotor coil 170A, the second rotor coil 170B, etc.) of the rotor 150 may form one or more loops around a corresponding permanent magnet 160, individual rotor coils 170 may be electrically connected to provide current and generate magnetic fields as desired. For example, one or both terminal ends of a given rotor coil 170 (e.g., the first rotor coil 170A, the second rotor coil 170B, etc.) may be electrically connected to a terminal end of another rotor coil 170, such as a circumferentially adjacent rotor coil 170. Accordingly, separate rotor coils 170 may be connected in series to provide current (e.g., from a power source) therethrough. Accordingly, separate rotor coils 170 may be connected in parallel to provide current (e.g., from a power source) therethrough.It is understood that the rotor coils 170 can be connected in series and / or parallel.

[0027] A group of winding segments 172 within one of the plurality of coil chambers 156 may be radially or otherwise offset from one another within the corresponding rotor coil chamber 156. Additionally or alternatively, the winding segments 172 within a given coil chamber 156 and / or different rotor coil chambers 156 may have different sizes, shapes, materials, and the like. While one coil chamber 156 is shown circumferentially between a given pair of circumferentially adjacent permanent magnets 160, any number of coil chambers 156 and / or rotor coils 170 may be provided between a pair of circumferentially adjacent permanent magnets 160. Additionally, any number of turns and / or winding segments 172 may be provided within a given coil chamber 156.

[0028] Now referring to Fig. 5, permanent magnets of a rotor can provide magnetic fields for coupling with a rotating magnetic field of a stator. As shown in Fig. 5, the stator coils 120 of the stator 110 can be operated to generate a rotating magnetic field 138. The stator coils 120 can, for example, be operated with variable current, with different segments thereof having a different current direction and / or current intensity at a given time. As the current direction and / or current intensity for each segment of the stator coils 120 changes over time, the magnetic field 138 generated near it can change accordingly. The rotating magnetic field 138 can extend through the rotor 150 to magnetically couple with the magnetic field generated by the permanent magnets 160 ( Fig. 5) and / or the rotor coils 170 ( Fig. 6). The rotating magnetic field 138 generated by the stator 110 can magnetically interact with such components of the rotor 150 to cause rotation of the rotor 150.

[0029] As in Fig. 5, the permanent magnets 160 may be distributed at different circumferential positions relative to one another. The permanent magnets 160 may have different magnetic orientations. For example, circumferentially adjacent ones of the permanent magnets 160 may have different (e.g., opposite) magnetic orientations with respect to the central axis. As another example, some permanent magnets 160 may have a north-south magnetic orientation such that the permanent magnetic fields 168 extending therethrough are directed toward the central axis, and some permanent magnets 160 may have a north-south magnetic orientation such that the permanent magnetic fields 168 extending therethrough are directed away from the central axis. It should be understood that each magnetic field may form closed loops, so that some portions of the magnetic field may be oriented in any direction.However, references herein to the orientation of a permanent magnet refer to the magnetic orientation within and immediately adjacent to the respective permanent magnet.

[0030] Now referring to Fig. 6, rotor coils can be arranged to generate temporary magnetic fields during operation that complement the permanent magnetic fields of the permanent magnets. As in Fig. 6, the rotor coils 170 may form winding segments, wherein each group of winding segments or other portions of a given rotor coil 170 may be circumferentially located between a corresponding adjacent pair of permanent magnets 160. Such a rotor coil 170 may be operated to receive a current and generate a temporary magnetic field 178. As shown in Fig. 6, each temporary magnetic field 178 may have sections thereof that represent each of the various permanent magnetic fields 168 (in Fig. 5) of the corresponding adjacent pair of permanent magnets 160. For example, each of the rotor coils 170 may be arranged and operated to receive a current and generate a temporary magnetic field 178 that extends through each of the corresponding adjacent pair of permanent magnets 160. The portions of the temporary magnetic field 178 that extend through each of the corresponding adjacent pair of permanent magnets 160 may be aligned with corresponding permanent magnetic fields generated by the corresponding adjacent pair of permanent magnets 160. As used herein, one magnetic field is aligned with another magnetic field when overlapping portion components of both magnetic fields each have a component that is parallel to the other. It should be understood that these portions need not be parallel in their entirety.Rather, the components may be parallel to each other, so that representative field lines at an intersection would form an angle of less than 90 degrees. As used herein, a magnetic field complements another magnetic field if the resulting combined magnetic field is stronger than either magnetic field alone. As, for example, in . Fig. 6, the density and number of magnetic field lines that define the temporary magnetic field 178 (including its combination with the Fig. 5) are greater in the entire rotor 150 than the density and number of magnetic field lines that represent the permanent magnetic fields 168 shown in Fig. 5. Such an arrangement may allow the permanent magnetic fields 168 and the temporary magnetic fields 178 to combine (e.g., constructively interfere) in a manner that creates a combined magnetic field that is stronger than either alone. This may also allow the permanent magnets 160 and the rotor coils 170 to have a stronger magnetic coupling with corresponding portions of the rotating magnetic field 138 generated by a stator 110 than would be the case with the permanent magnets 160 alone (i.e., without operation of the rotor coils 170).

[0031] Now referring to Fig. 7 and Fig. 8, a different arrangement of permanent magnets and rotor coils can provide either permanent and / or temporary magnetic fields for coupling with a rotating magnetic field of a stator. As shown in Fig. 7, a plurality of (e.g., two or more) permanent magnets 160 may be grouped between a circumferentially adjacent pair of rotor coils 170. For example, each group of permanent magnets 160 may include constituent permanent magnets 160 having different positions and / or orientations relative to one another. For example, adjacent permanent magnets 160 may be Fig. 7 tilted or otherwise arranged to form an angle with each other. The permanent magnets 160 within a group may optionally have symmetry about an axis, such as an axis that intersects the central axis of the rotor 150. The permanent magnets 160 within a group may have similar magnetic orientations to create a combined permanent magnetic field 168. In some embodiments, circumferentially adjacent groups of permanent magnets 160 may have different (e.g., opposite) magnetic orientations with respect to the central axis. It is understood that the permanent magnets 160 and their groups may be provided in any arrangement, position, and / or orientation to form the resulting permanent magnetic field 168.

[0032] As in Fig. 8, the rotor coils 170 may form winding segments, wherein each group of winding segments or other portions of a given rotor coil 170 may be circumferentially located between a corresponding adjacent pair of groups of permanent magnets 160. Such a rotor coil 170 may be operated to receive a current and generate a temporary magnetic field 178, which may have portions thereof that may comprise each of the various permanent magnetic fields 168 (in Fig. 7) of the corresponding adjacent pair of groups of permanent magnets 160. It is understood that the rotor coils 170 and 172 can be provided in any arrangement, position, and / or orientation to form the resulting temporary magnetic field 178.

[0033] Now referring to Fig. 9 and Fig. 10, a different arrangement of permanent magnets and coils can provide either permanent and / or temporary magnetic fields for coupling with a rotating magnetic field of a stator. As shown in Fig. 9, multiple (e.g., two or more) permanent magnets 160 may be grouped near an adjacent rotor coil 170. For example, each group (e.g., each pair) of permanent magnets 160 may include constituent permanent magnets 160 located on opposite sides of an opening 158 in the rotor body 152 of the rotor 150. Such permanent magnets 160 may further be radially adjacent to (e.g., overlapping with) a corresponding coil 170. For example, the permanent magnets 160 may be disposed radially adjacent to a rotor coil 170 rather than between two circumferentially adjacent rotor coils 170. The permanent magnets 160 within a group (e.g., those adjacent to a particular rotor coil 170) may have similar magnetic orientations to create a combined permanent magnetic field 168.In some embodiments, circumferentially adjacent groups of permanent magnets 160 (e.g., each group adjacent to a corresponding coil 170) may have different (e.g., opposite) magnetic orientations relative to the central axis. It is understood that the permanent magnets 160 and their groups may be provided in any arrangement, position, and / or orientation to form the resulting permanent magnetic field 168.

[0034] As in Fig. 10, the rotor coils 170 may form winding segments, wherein each group of winding segments or other portions of a given rotor coil 170 may be circumferentially adjacent to a corresponding group of permanent magnets 160. Such a rotor coil 170 may be operated to receive a current and generate a temporary magnetic field 178, which may have portions thereof that may constitute each of the various permanent magnetic fields 168 (in Fig. 9) of the corresponding groups of permanent magnets 160. It is understood that the rotor coils 170 can be provided in any arrangement, position, and / or orientation to form the resulting temporary magnetic field 178.

[0035] Now referring to Fig. 11 and Fig. 12, a different arrangement of permanent magnets and coils can provide either permanent and / or temporary magnetic fields for coupling with a rotating magnetic field of a stator. As shown in Fig. 11 and Fig. 12, the permanent magnets 160 can be distributed with different circumferential positions relative to each other. While in Fig. 11 and Fig. 12, it is understood that any arrangement of the permanent magnets 160, including those illustrated herein, may be provided. As shown in Fig. 11 and Fig. 12, the rotor coils 170 may form winding segments, where each group of winding segments or other portions of a given rotor coil 170 may be circumferentially adjacent to a corresponding permanent magnet 160. Multiple (e.g., two or more) rotor coils 170 may be positioned on opposite (e.g., circumferential) sides of a given permanent magnet 160.

[0036] The rotor coils 170 can be operated in different modes to generate different magnetic fields. For example, any given pair of rotor coils 170 on opposite sides of a corresponding permanent magnet 160 can conduct current in the same direction ( Fig. 11) or in different (e.g. opposite) directions ( Fig. 12). As another example, any given pair of rotor coils 170 between a circumferentially adjacent pair of permanent magnets 160 can conduct current in different (e.g., opposite) directions ( Fig. 11) or in the same direction ( Fig. 12). For example, the current directions may be parallel to the central axis. It is understood that such coils may be independently controlled to receive current in either direction as desired. Accordingly, the rotor coils 170 need not be connected in series or parallel, but may be independently controlled as desired (e.g., by a power source). The rotor coils 170 may generate a temporary magnetic field 178, which may include portions thereof that complement each of the various permanent magnetic fields of the permanent magnets 160. It is understood that the rotor coils 170 may be provided in any arrangement, position, orientation, and / or operating mode to shape the resulting temporary magnetic field 178.For example, the different current directions can shape the resulting temporary magnetic field 178 in different ways depending on the direction and / or strength of the current through each rotor coil 170 and / or depending on which rotor coils 170 are being operated. Thus, the rotor coils 170 can influence the permanent magnetic fields of the permanent magnets 160 in a variety of ways to generate the desired magnetic field.

[0037] Now referring to Fig. 13, the torque output of a motor can be controlled based on the operation of the rotor coils described herein. For example, the different cases (e.g., Case 1, Case 2, Case 3, and Case 4) correspond to different amounts of current supplied to rotor coils of a rotor during the generation of a rotating magnetic field from a stator. At the lowest torque output (i.e., Case 4), no current is supplied to the rotor coils. Thus, only the permanent magnetic fields of the permanent magnets are used to magnetically couple the rotor to the rotating magnetic field of the stator. In other cases (i.e., Case 1 at 15 A, Case 2 at 10 A, and Case 3 at 5 A), a non-zero current is supplied to the rotor coils. The current in Case 2 is higher than the current supplied in Case 3, and the current in Case 1 is higher than the current supplied in Case 2.Both the torque values ​​over time and the average of those values ​​are shown in the graph. It should be understood that the current amounts disclosed herein are merely exemplary and that any amount of current may be provided, including values ​​between or greater than those disclosed herein. As shown, with greater current, the torque increases accordingly. The temporary magnetic fields generated by the rotor coils complement the permanent magnetic fields of the permanent magnets. This increases the strength of the magnetic coupling with the rotating magnetic field. Accordingly, the torque can be increased to increase the output even against resistance. Such torque output can be provided in response to the demand for torque (or increased torque) as further described herein.For example, the rotor coils can be operated to provide the torque output required to meet a torque demand.

[0038] Fig. 14 illustrates a flowchart of an exemplary process 800 for operating an electric motor according to one or more implementations of the subject technology. For purposes of explanation, the process 800 is primarily described herein with reference to the motor 10 of Fig. 1 and Fig. 2, the rotor 150 of Fig. 3 to 4, the engines of Fig. 5 to 12 and / or various components thereof. However, the process 800 is not limited to the engine 10 of Fig. 1 and Fig. 2 and / or the rotor 150 of Fig. 3 to 4, the engines of Fig. 5 to 12, and one or more blocks (or operations) of the process 800 may be performed by one or more other structural components of the engine 10 of Fig. 1 and Fig. 2 and / or the rotor 150 of Fig. 3 to 4, the engines of Fig. 5 through 12 and / or other suitable devices, apparatus, or systems. Further, for purposes of explanation, some of the blocks of process 800 are described herein as occurring serially or linearly. However, multiple blocks of process 800 may occur in parallel. In addition, the blocks of process 800 need not be performed in the order shown, and / or one or more blocks of process 800 need not be performed and / or may be replaced by other operations.

[0039] At block 802, an electric motor may be operated (e.g., by a processor) to generate a rotating magnetic field. The rotating magnetic field may be generated by passing a current through each of a plurality of stator coils, with segments of their winding distributed around a rotor of the motor. The rotating magnetic field generated by the stator may rotate about a central axis of the rotor. The rotating magnetic field may further extend through the rotor, which may include permanent magnets and rotor coils. The permanent magnets of the rotor generate permanent magnetic fields that can respond to the rotating magnetic field by rotating the rotor so that the permanent magnetic fields of the permanent magnets remain aligned with the corresponding portions of the rotating magnetic field. Accordingly, the permanent magnets of the rotor may be magnetically coupled to the rotating magnetic field of the stator.

[0040] At block 804, a torque demand may be determined (e.g., by a processor). The torque demand may be based on input from a control unit, user input, and the like. For example, a processor or other control unit may determine an amount of output (e.g., torque) to be provided by the shaft coupled to the rotor. As another example, a user may actuate an input device, such as an accelerator pedal, a pedal, and the like, to determine a desired power output of the motor and / or the shaft. In some embodiments, the torque demand may be determined as the presence and / or amount of torque in excess of what can be provided based on the magnetic coupling between the rotating magnetic field and the permanent magnets. The torque demand may be determined based on sensed conditions (e.g., with a sensor) and / or predicted outputs (e.g.,based on a predictive model).

[0041] At block 806, it may be determined (e.g., by a processor) whether the torque demand is above or below a threshold. The threshold may be based on a current output of the motor (e.g., at the shaft) and / or a desired torque. For example, the output (e.g., torque) of the motor may be determined and compared to a desired output (e.g., torque) to determine whether the present output satisfies a torque demand. If it is determined that the torque demand is below or at the threshold (i.e., not above the threshold), the process 800 may return to block 804 and / or another operation and / or process. If it is determined that the torque demand is above a threshold, the process 800 may continue to block 808.

[0042] At block 808, the rotor coils of the rotor may be operated (e.g., by a processor) to generate temporary magnetic fields. The temporary magnetic fields may be generated in addition to the permanent magnetic fields of the permanent magnets. For example, during operation of the rotor coils, each of the temporary magnetic fields may extend through each of a corresponding adjacent pair of the permanent magnets. Portions of each temporary magnetic field that extend through each of the corresponding adjacent pairs of the permanent magnets may be aligned with corresponding permanent magnetic fields generated by the corresponding adjacent pair of the permanent magnets.

[0043] Fig. 15 illustrates an exemplary electronic system 900 with which aspects of the present disclosure may be implemented. The electronic system 900 may be any electronic device for providing the features and performing processes as described with reference to Fig. 1 to 4, including, but not limited to, a vehicle, computer, server, smartphone, and a wearable device (e.g., an authentication device). The electronic system 900 may include various types of computer-readable media and interfaces for various other types of computer-readable media. The electronic system 900 includes a persistent storage device 902, system memory 904 (and / or buffers), an input device interface 906, an output device interface 908, sensor(s) 910, ROM 912, processing unit(s) 914, a network interface 916, a bus 918, and / or subsets and variations thereof.

[0044] The bus 918 represents all of the system, peripheral, and chipset buses that connect the numerous internal devices and / or components of the electronic system 900, such as any of the engine 10 of Fig. 1 and Fig. 2, of the rotor 150 of Fig. 3 to 4, the engines of Fig. 5 to 12, and / or various components thereof. In one or more implementations, bus 918 communicatively connects the one or more processing units 914 to the ROM 912, the system memory 904, and the persistent storage device 902.

[0045] From these various memory units, the one or more processing units 914 retrieve instructions for execution and data for processing to perform the processes of the present disclosure. The one or more processing units 914 may be a single processor or a multi-core processor in various implementations. In one or more implementations, one or more of the processing units 914 may be included on an ECU 204, such as in the form of processor 206.

[0046] The ROM 912 stores static data and instructions required by the one or more processing units 914 and other modules of the electronic system 900. The persistent storage device 902, on the other hand, may be a read-write memory device. The persistent storage device 902 may be a non-volatile memory device that stores instructions and data even when the electronic system 900 is powered off. In one or more implementations, a mass storage device (such as a magnetic or optical disk and its corresponding disk drive) may be used as the persistent storage device 902.

[0047] In one or more implementations, a removable storage device (such as a floppy disk, a flash drive, and its corresponding disk drive) may be used as the persistent storage device 902. Like the persistent storage device 902, the system memory 904 may be a read / write storage device. However, unlike the persistent storage device 902, the system memory 904 may be a volatile read / write memory, such as RAM. The system memory 904 may store any of the instructions and data that one or more processing units 914 may need at runtime. In one or more implementations, the processes of the subject disclosure are stored in the system memory 904, the persistent storage device 902, and / or the ROM 912.From these various storage units, the one or more processing units 914 retrieve instructions to execute and data to process to perform the processes of one or more implementations.

[0048] The persistent storage device 902 and / or the system memory 904 may include one or more machine learning models. Machine learning models such as those described herein are often used to make predictions, solve problems, detect objects in image data, and the like. For example, machine learning models described herein may be used to predict whether an authorized user is approaching a vehicle and intends to open a charging port closure. Various implementations of the machine learning model are possible. For example, the machine learning model may be a deep learning network, a transformer-based model (or other attention-based models), a multi-layer perceptron or other feed-forward networks, neural networks, and the like.In various examples, machine learning models can be more adaptable because machine learning models can be improved over time by retraining the models as additional data becomes available.

[0049] Bus 918 is also connected to input device interfaces 906 and output device interfaces 908. Input device interface 906 allows a user to communicate information and select commands to electronic system 900. Input devices that can be used with input device interface 906 can include, for example, alphanumeric keyboards, touchscreens, and pointing devices. Output device interface 908 can enable electronic system 900 to communicate information to users. For example, output device interface 908 can provide for the display of images generated by electronic system 900.Output devices that can be used with the output device interface 908 can include, for example, printers and display devices such as a liquid crystal display (LCD), a light-emitting diode (LED) display, an organic light-emitting diode (OLED) display, a flexible display, a flat panel display, a solid-state display, a projector, or any other device for outputting information.

[0050] One or more implementations may include devices that function as both input and output devices, such as a touchscreen. In these implementations, the feedback provided to the user may be any form of sensory feedback, such as visual feedback, auditory feedback, or tactile feedback; and input from the user may be received in any form, including auditory input, speech, or tactile input.

[0051] Bus 918 is also connected to sensor(s) 910. Sensor(s) 910 may include a location sensor that may be used in determining device position based on a positioning technology. For example, the position sensor may provide one or more of GNSS positioning, wireless access point positioning, cellular phone signal positioning, Bluetooth signal positioning, machine vision positioning, and / or an inertial navigation system (e.g., via motion sensors such as an accelerometer and / or gyroscope). In one or more implementations, sensor(s) 910 may be used to detect movement, tracking, and orientation of electronic system 900. For example, the sensor(s) may include a torque sensor, a resolver, an accelerometer, a rate gyroscope, and / or one or more other motion-based sensors.The sensor(s) 910 may include one or more biometric sensors and / or image sensors for authenticating a user.

[0052] Bus 918 also couples electronic system 900 to one or more networks and / or to one or more network nodes via one or more network interfaces 916. In this way, electronic system 900 may be part of a network of computers (such as a local area network or a wide area network). Any or all components of electronic system 900 may be used in connection with the present disclosure.

[0053] Implementations within the scope of the present disclosure may be realized partially or entirely using a tangible computer-readable storage medium (or multiple tangible computer-readable storage media of one or more types) encoding one or more instructions. The tangible computer-readable storage medium may also be non-transitory.

[0054] The computer-readable storage medium may be any storage medium that can be read, written, or otherwise accessed by a general-purpose or special-purpose computing device, including any processing electronics and / or processing circuitry capable of executing instructions. For example, the computer-readable medium may include, without limitation, any volatile semiconductor memory, such as RAM, DRAM, SRAM, T-RAM, Z-RAM, and TTRAM. The computer-readable medium may also include any non-volatile semiconductor memory, such as ROM, PROM, EPROM, EEPROM, NVRAM, Flash, nvSRAM, FeRAM, FeTRAM, MRAM, PRAM, CBRAM, SONOS, PRAM, NRAM, Racetrack memory, FJG, and Millipede memory.

[0055] Furthermore, the computer-readable storage medium may include any non-semiconductor storage, such as optical disk storage, magnetic disk storage, magnetic tape, other magnetic storage devices, or any other medium capable of storing one or more instructions. In one or more implementations, the tangible computer-readable storage medium may be directly coupled to a computing device, while in other implementations, the tangible computer-readable storage medium may be indirectly coupled to a computing device, e.g., via one or more wired connections, one or more wireless connections, or any combination thereof.

[0056] Instructions may be directly executable or may be used to develop executable instructions. For example, instructions may be implemented as executable or non-executable machine code, or as instructions in a high-level language that can be compiled to produce executable or non-executable machine code. Further, instructions may also be implemented as data or include data. Computer-executable instructions may also be organized in any format, including routines, subroutines, programs, data structures, objects, modules, applications, applets, functions, etc. As is known to those skilled in the art, details, including but not limited to the number, structure, sequence, and organization of instructions, may vary considerably without varying the underlying logic, function, processing, and output.

[0057] While the above discussion primarily refers to microprocessors or multi-core processors executing software, one or more implementations are performed by one or more integrated circuits, such as ASICs or FPGAs. In one or more implementations, such integrated circuits execute instructions stored on the circuit itself.

[0058] A reference to an element in the singular shall not mean one and only one, unless expressly stated so, but rather one or more. For example, "a" module may refer to one or more modules. An element preceded by "a," "an," or "the" excludes the presence of additional identical elements, without further limitation.

[0059] Headings and subheadings, if any, are used for convenience only and do not limit the invention. The word "exemplary" is used herein to mean serving as an example or illustration. To the extent the term "including," "comprising," or the like is used, such term is intended to be inclusive in a similar manner to the term "comprising" when used as a transitional word in a claim. Relational terms such as first and second and the like may be used to distinguish one entity or act from another without necessarily requiring or implying any actual such relationship or order between such entities or acts.

[0060] Terms such as an aspect, the aspect, another aspect, some aspects, one or more aspects, an implementation, the implementation, another implementation, some implementations, one or more implementations, an embodiment, the embodiment, another embodiment, some embodiments, one or more embodiments, a configuration, the configuration, another configuration, some configurations, one or more configurations, the present technology, the disclosure, the present disclosure, other variations thereof, and the like are for convenience and do not imply that any disclosure referring to such term(s) is essential to the present technology or that such disclosure applies to all configurations of the present technology.A disclosure referring to such a term(s) may apply to all configurations or to one or more configurations. A disclosure referring to such a term(s) may provide one or more examples. A term, such as an aspect or some aspects, may refer to one or more aspects, and vice versa, and this applies similarly to other above terms.

[0061] The phrase "at least one of" preceding a list of items with the phrase "and" or "or" separating one of the items modifies the list as a whole, rather than each item of the list. The phrase "at least one of" does not require selection of at least one item; rather, the phrase allows for a meaning that includes at least one of the items and / or at least any combination of the items and / or at least one of the items. For example, each of the phrases "at least one of A, B, and C" or "at least one of A, B, or C" refers to only A, only B, or only C; any combination of A, B, and C; and / or at least one of A, B, and C.

[0062] It is understood that the specific order or hierarchy of disclosed steps, acts, or processes is illustrative of exemplary approaches. Unless expressly stated otherwise, it is understood that the specific order or hierarchy of steps, acts, or processes may be performed in various orders. Some of the steps, acts, or processes may be performed concurrently. The appended method claims, if any, present elements of the various steps, acts, or processes in a sample order and are not limited to the specific order or hierarchy in which they are presented. These may be performed serially, linearly, in parallel, or in different orders.It is understood that the instructions, operations, and systems described may generally be integrated together in a single software / hardware product or may be packaged into multiple software / hardware products.

[0063] Terms such as top, bottom, front, back, side, horizontal, vertical, and the like refer to any reference frame other than the ordinary gravitational frame. Thus, such a term can extend upward, downward, diagonally, or horizontally in a gravitational frame.

[0064] The disclosure is provided to enable any person skilled in the art to practice the various aspects described herein. In some cases, well-known structures and components are shown in block diagram form to avoid obscuring the concepts of the subject technology. The disclosure provides various examples of the subject technology, and the subject technology is not limited to these examples. Various modifications to these aspects will be readily apparent to those skilled in the art, and the principles described herein may be applied to other aspects.

[0065] All structural and functional equivalents to the elements of the various aspects described in the disclosure that are known or later become known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Furthermore, nothing disclosed herein is intended to be made available to the public, regardless of whether such disclosure is expressly recited in the claims. No claim element is to be construed within the provisions of 35 USC § 112(f) unless the element is expressly recited using the phrase "means for" or, in the case of a method claim, the element is recited using the phrase "step for."

[0066] Those skilled in the art would recognize that the various illustrative blocks, modules, elements, components, methods, and algorithms described herein may be implemented in hardware, electronic hardware, computer software, or combinations thereof. To illustrate this interchangeability of hardware and software, various illustrative blocks, modules, elements, components, methods, and algorithms have been described generally in terms of their functionality. Whether such functionality is implemented in hardware or software depends on the particular application and design constraints imposed on the overall system. Those skilled in the art may implement the described functionality in different ways for each particular application. Various components and blocks may be arranged differently (e.g.,arranged in a different order or partitioned in a different way) without departing from the scope of the present technology.

[0067] The title, brief description of the drawings, abstract, and drawings are hereby incorporated into the disclosure and are provided as illustrative examples of the disclosure, not as limiting descriptions. They are submitted with the understanding that they will not be used to limit the scope or meaning of the claims. Additionally, it will be apparent in the detailed description that the description provides illustrative examples and the various features are grouped into various implementations to streamline the disclosure. The method of the disclosure should not be interpreted to reflect an intent that the claimed subject matter requires more features than are expressly recited in each claim.Rather, as the claims reflect, the inventive subject matter lies in less than all features of a single disclosed configuration or process. The claims are hereby incorporated into the Detailed Description, with each claim standing alone as separately claimed subject matter.

[0068] The claims are not intended to be limited to the aspects described herein, but are intended to give the full scope of protection consistent with the language of the claims and including all legal equivalents. Notwithstanding the foregoing, none of the claims are intended, nor should they be interpreted, to encompass subject matter that does not meet the requirements of applicable patent law.

Claims

[1] Rotor for an electric motor, the rotor comprising: a body configured to rotate about a central axis; Permanent magnets within the body and spaced circumferentially around the central axis and Rotor coils within the body, each of the rotor coils forming winding segments circumferentially positioned between a corresponding adjacent pair of the permanent magnets, each of the rotor coils being configured to receive a current and generate a temporary magnetic field extending through each of the corresponding adjacent pairs of the permanent magnets, portions of the temporary magnetic field extending through each of the corresponding adjacent pairs of the permanent magnets being aligned with corresponding permanent magnetic fields generated by the corresponding adjacent pair of the permanent magnets. [2] A rotor according to claim 1, wherein circumferentially adjacent ones of the permanent magnets have different magnetic orientations with respect to the central axis. [3] The rotor of claim 1, wherein the body defines a plurality of magnetic chambers, each of the permanent magnets being disposed within a corresponding one of the plurality of magnetic chambers. [4] The rotor of claim 3, wherein the body defines cover portions each radially disposed between a corresponding one of the plurality of magnet chambers and a radially outermost side of the rotor. [5] A rotor according to claim 3, wherein a group of the permanent magnets within one of the plurality of magnet chambers is circumferentially offset with respect to one another. [6] The rotor of claim 4, wherein the body further defines a plurality of coil chambers, each of the rotor coils extending through a respective pair of the plurality of coil chambers, the respective pair of the plurality of coil chambers being located on radially opposite sides of the central axis. [7] The rotor of claim 6, wherein the body defines openings each radially disposed between a corresponding one of the plurality of coil chambers and the radially outermost side of the rotor. [8] A rotor according to claim 1, wherein the winding segments extend longitudinally within the body between opposite ends of the rotor. [9] Engine, comprising: a stator having stator coils configured to generate a rotating magnetic field; and a rotor configured to rotate about a central axis, and comprising: Permanent magnets spaced circumferentially from one another around the central axis, wherein circumferentially adjacent ones of the permanent magnets generate different permanent magnetic fields with respect to the central axis; and Rotor coils each forming winding segments, each group of winding segments circumferentially located between a corresponding adjacent pair of permanent magnets being configured to receive a current and generate a temporary magnetic field that complements the different permanent magnetic fields of the corresponding adjacent pair of permanent magnets. [10] The motor of claim 9, wherein the rotor comprises a body defining a plurality of magnetic chambers, each of the permanent magnets being disposed within a corresponding one of the plurality of magnetic chambers. [11] The motor of claim 10, wherein the body defines cover portions each radially disposed between a corresponding one of the plurality of magnet chambers and a radially outermost side of the rotor. [12] The motor of claim 10, wherein a group of the permanent magnets within one of the plurality of magnet chambers is circumferentially offset with respect to each other. [13] The motor of claim 11, wherein the body further defines a plurality of coil chambers, each of the rotor coils extending through a corresponding pair of the plurality of coil chambers. [14] The motor of claim 13, wherein the body defines openings each radially disposed between a corresponding one of the plurality of coil chambers and the radially outermost side of the rotor. [15] A motor according to claim 9, wherein segments of the stator coils extend longitudinally between opposite ends of the stator and the winding segments of the rotor coils extend longitudinally between opposite ends of the rotor. [16] A motor according to claim 9, wherein each of the rotor coils extends to radially opposite sides of the central axis. [17] Method comprising: Operating stator coils of a stator to generate a rotating magnetic field extending through a rotor comprising permanent magnets and rotor coils, the permanent magnets of the rotor generating permanent magnetic fields; Determine the torque requirement and when the torque demand is above a threshold, operating the rotor coils of the rotor to generate temporary magnetic fields that supplement the permanent magnetic fields of the permanent magnets. [18] The method of claim 17, wherein, in operating the rotor coils, each of the temporary magnetic fields extends through each corresponding adjacent pair of the permanent magnets, portions of each temporary magnetic field extending through each of the corresponding adjacent pair of the permanent magnets being aligned with corresponding permanent magnetic fields generated by the corresponding adjacent pair of the permanent magnets. [19] The method of claim 18, wherein circumferentially adjacent ones of the permanent magnets have different magnetic orientations with respect to a central axis of the rotor. [20] The method of claim 17, wherein when the rotor coils are driven by a current, a magnetic coupling between the rotor and the stator is stronger than when the rotor coils are not driven.

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