Device and method of operating a device

Abstract

The invention relates to a device and a method of operating a device. In some embodiments, two or more different types of stator structures may be disposed within the gap of the axial flux machine. Such an arrangement may be advantageous, for example, for producing an electric machine optimized for a variety of modes of operation, such as mechanical torque generation, conversion of mechanical torque to electrical energy, and / or dissipation of mechanical energy. Further, in some embodiments, the axial flux electric machine may include a planar stator having windings arranged to be positioned within an active region of the electric machine, and may further include at least one switch configured to be selectively turned off, to establish an electrical connection between respective ends of the windings when the windings are not coupled to an external power source.

Description

[0001] This application is a divisional application of the invention patent application with Chinese application number 202280015050.X, filed on February 14, 2022, and invention name “Planar stator structure for axial flux motor”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 150,129, filed on February 17, 2021, entitled “MULTI-STATORAXIAL FLUX MACHINE,” under 35 U.S.C. §119(e). Background Art

[0004] An axial flux motor and axial flux generator described by U.S. Patent No. 7,109,625 ("the '625 patent"), which is incorporated herein by reference in its entirety, has a planar printed circuit board stator assembly disposed between rotor assemblies that support magnets with alternating north and south poles. The magnetic flux between the magnets interacts with the current density supported by the traces in the printed circuit stator to produce torque.

[0005] This type of electric machine can operate as either a motor or a generator, and has a number of useful characteristics, including that the torque as a function of angle can be smooth and have high quality motion. Summary of the invention

[0006] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features, nor is it intended to limit the scope of the appended claims.

[0007] In some of the disclosed embodiments, a planar stator for an axial flux motor having a rotor including one or more magnets that generate a first magnetic flux substantially parallel to the axis of rotation of the rotor in an active region within a gap of the axial flux motor comprises: at least a first terminal, a second terminal, a third terminal, and a fourth terminal, each terminal being adapted to be connected to an electrical circuit located outside the planar stator; at least one first winding arranged to be positioned within the active region, the at least one first winding having a first end and a second end electrically connected to the first terminal and the second terminal, respectively, wherein an electrical characteristic between the first terminal and the second terminal measured when the first terminal and the second terminal are not connected to the electrical circuit has a first value; and at least one second winding arranged to be positioned within the active region, the at least one second winding being electrically isolated from the at least one first winding and having a third end and a fourth end electrically connected to the third terminal and the fourth terminal, respectively, wherein an electrical characteristic between the third terminal and the fourth terminal measured when the third terminal and the fourth terminal are not connected to the electrical circuit has a second value significantly different from the first value.

[0008] In some embodiments, a planar stator for an axial flux motor having a rotor including one or more magnets that generate a first magnetic flux substantially parallel to the axis of rotation of the rotor in an active region within a gap of the axial flux motor comprises: a first conductive sheet arranged to be positioned within the active region so that eddy currents generated within the first conductive sheet exert a drag on the rotor; and at least a first winding arranged to be positioned within the active region, the first winding having at least a first terminal and a second terminal electrically connected to respective ends of the first winding.

[0009] In some embodiments, a planar stator for an axial flux motor having a rotor including one or more magnets that generate a first magnetic flux substantially parallel to the axis of rotation of the rotor in an active region within a gap of the axial flux motor includes: at least a first winding arranged to be positioned within the active region, the first winding having at least a first terminal and a second terminal electrically connected to respective ends of the first winding; and at least one switch configured to be selectively closed when the first winding is not connected to an external power source to establish an electrical connection between the first terminal and the second terminal. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The objects, aspects, features and advantages of the embodiments disclosed herein will become more fully apparent from the following detailed description, the appended claims and the accompanying drawings, in which the same reference numerals identify similar or identical elements. Reference numerals introduced into the specification in association with the drawings may be repeated in one or more subsequent drawings without additional description in the specification to provide context for other features, and not every element will be labeled in every drawing. The drawings are not necessarily to scale, with emphasis instead on illustrating the embodiments, principles and concepts. The drawings are not intended to limit the scope of the appended claims.

[0011] Figure 1 An exploded view of the internal components of an example axial flux electric machine having a planar stator is shown;

[0012] Figure 2 Shown include Figure 1 A cross-sectional view of an axial flux machine with components shown in ;

[0013] Figure 3 A variation of an axial flux machine comprising a planar stator segment is shown;

[0014] Figure 4 shows an exploded view of the internal components of an example axial flux electric machine having a planar stator constructed in accordance with some embodiments of the present disclosure;

[0015] Figure 5 Shown include Figure 6 A cross-sectional view of an axial flux machine with components shown in ;

[0016] Figure 6 Shows Figure 4 and Figure 5 A perspective view of an axial flux machine shown in , with the shaft and upper rotor assembly removed so that the orientation of the various segment types can be clearly seen;

[0017] Figure 7 A first example implementation of a planar axial flux electric machine including a variety of different stator structure types is shown;

[0018] Fig. 8A A first possible scheme for driving three windings (or receiving power from three windings) through a plurality of terminals is illustrated;

[0019] Figure 8B A first possible scheme for driving three windings (or receiving power from three windings) through a plurality of terminals is illustrated;

[0020] Figure 8C A first possible scheme for driving three windings (or receiving power from three windings) through a plurality of terminals is illustrated;

[0021] Fig. 9 A second example implementation of a planar axial flux electric machine including a plurality of different stator structure types is shown;

[0022] Fig.10 A third example implementation of a planar axial flux electric machine including a variety of different stator structure types is shown;

[0023] Fig.11 An example of a planar axial flux machine having a new segment configuration that may be employed alone or in conjunction with one or more additional or different segment structures is shown;

[0024] Fig.12 A fourth example implementation of a planar axial flux electric machine including a plurality of different stator structure types is shown;

[0025] Fig.13 A fifth example implementation of a planar axial flux electric machine including a plurality of different stator structure types is shown; and

[0026] Fig.14 A sixth example implementation of a planar axial flux electrical machine including a variety of different stator structure types is shown. DETAILED DESCRIPTION

[0027] Variations of the motor described in the '625 patent use stators that do not form a complete ring shape. In particular, one or more planar stator segments made using printed circuit board (PCB) manufacturing or similar techniques can be disposed in the gap between the rotors. Motors of the type described in U.S. Patent Application Publication No. 2020 / 067361 ("the '361 Publication"), the entire contents of which are incorporated herein by reference, can support angle-dependent torque requirements. In these types of applications, portions of the rotor densely populated with magnets are aligned with stator segments at angles required for maximum torque. Also discussed in the '361 Publication is the possibility of a motor in which the stator includes one or more segments, but the rotor is similar to the rotor in the '625 patent in that the poles are evenly mounted. Motors similar to the motor described in the '625 patent can be made by assembling a complete annular ring from segments, rather than making the motor from a monolithic circuit board.

[0028] Particularly disclosed herein is an axial flux electric machine comprising a plurality of stator structures disposed within a gap between rotors, wherein at least two of the stator structures have different functions (including the possibility that one of the structures is a conductive sheet that introduces eddy current braking but cannot produce motor action or operate as a generator). Such a configuration may result in an electric machine having thermal, electrical, and mechanical performance that cannot be achieved using a single stator structure or multiple identical stator structures. In some implementations, such functionality may be achieved by arranging the various stator segments at different angular positions relative to the axis of rotation of the electric machine within the gap. In other implementations, the different stator structures may be arranged to at least partially overlap each other within the gap, such as by arranging the various stator structures on different layers of the same printed circuit board.

[0029] The inventors have also recognized and appreciated that certain of the stator structures disclosed herein, and / or external circuits associated with these structures, are novel in themselves and allow for new and advantageous functionality when employed within an axial flux electric machine. Thus, as described in more detail below, certain of the novel stator structures disclosed herein need not be employed with one or more other types of stator structures according to some embodiments.

[0030] Figure 1 and Figure 2 1 and 2 show an exploded view and a cross-sectional view of a planar stator axial flux motor 100, respectively. Figure 1 and Figure 2 As shown, the planar stator 102 can be placed in the gap of the magnetic circuit established by the components of the rotor. Figure 1 As best shown in FIG. 1 , the rotor may include magnets 104a, 104b and support structures 106a, 106b that together form a pair of rotor assemblies 108a, 108b that may be attached to a shaft 110 of the rotor. Figure 2 As shown, the outer edge 112 of the stator 102 can be fixedly secured to the housing 114 (e.g., by being held between the various sections 114a, 114b of the housing 114), and the rotor shaft 110 (to which the rotor assemblies 108a, 108b are attached) can be rotatable relative to the housing 114 (e.g., via bearings 116).

[0031] In motor mode, a current density that rotates synchronously around the rotation axis of the rotor can be applied to the stator 102 by the controller 118 ( Figure 1108a, 108b). The interaction of this current density with the magnetic flux in the gap from the rotor assemblies 108a, 108b results in torque from the electromagnetic source. The controller 118 can be operated so that the energy conversion affected by this structure is bidirectional, that is, the motor can absorb electrical energy from the mechanical terminals and deliver it to the electrical terminals, or the motor can deliver electrical energy to the mechanical terminals. Under proper control, this type of motor can simulate various mechanical loads, including friction components, rotational inertia, and the like.

[0032] Figure 3 A variation of a planar axial flux machine is shown in which the stator is not a ring, but rather a segment 302. Producing the stator in the manner identified in the '361 publication can have various advantages, including that the machine can be designed to achieve greater manufacturing efficiency and / or accommodate loads that are cyclical in nature. This can be particularly advantageous when the radius of the machine is large.

[0033] As described above, according to some aspects of the present disclosure, two or more different types of stator structures may be provided within the gap of an axial flux machine, such as the above-described planar axial flux machine 100. Such an arrangement may be advantageous, for example, to produce a machine optimized for multiple operating modes, such as mechanical torque generation, conversion of mechanical torque to electrical power, and / or dissipation of mechanical energy.

[0034] Figure 4 and Figure 5 An exploded view and a cross-sectional view are shown, respectively, of one possible structure of such a planar axial flux electric machine 400. In the illustrated example, the electric machine 400 includes four stator segments 402a, 402b, 404a, 404b that are angularly offset from one another relative to the axis of rotation of the rotor. In other implementations, the electric machine 400 may instead have additional or fewer segments.

[0035] Figure 6 Shows Figure 4 and Figure 5 , wherein the shaft 110 and the upper rotor assembly 108a are removed so that the orientation of the various segment types can be clearly seen. Figure 4 and Figure 6As indicated by the markings on the individual segments 402a, 402b, 404a, 404b in, in some implementations, two of the segments (e.g., segments 402a and 402b) may be type "A" and two of the segments (e.g., segments 404a and 404b) may be type "B". In other implementations, a different number of individual segment types may be provided, and / or additional segment types (e.g., one or more type "C" segments) may be employed along with other segment types. For example, in some implementations, the motor 400 may instead be configured to have: (1) three type "A" segments and one type "B" segment; (2) two type "B" segments and one type "A" segment; (3) one type "A" segment and one type "B" segment; (4) two type "A" segments, one type "B" segment and one type "C" segment, etc. As shown in Figures 4 to 6 As can also be seen in FIG. 4 , certain types of segments may include one or more terminals 406 configured to enable connection between conductive traces on the segment (e.g., conductive traces forming one or more windings) and circuits external to the segment. Examples of certain types of segments that may include such terminals 406 are described below.

[0036] In some implementations, such as in Figure 1 and Figure 2 In the case of the motor 100 shown, the poles of the magnets 104a, 104b of the motor 400 can be evenly distributed around the axis of rotation of the rotor. Figure 3 As in the case of the illustrated electric machine 300 , the poles of the magnets 104 a , 104 b of the electric machine 400 may be distributed non-uniformly about the axis of rotation of the rotor.

[0037] Figure 7 A first exemplary implementation of a planar axial flux machine 700 is shown, the planar axial flux machine 700 comprising a Figures 4 to 6 A number of different stator construction types are described. Figure 6 , Figure 7 The upper rotor assembly 108a is not depicted in the drawing so that the two example stator segments 702, 704 included in the motor 700 can be clearly seen. Figure 7 Only two stator segments 702, 704 are shown, but as previously described, it should be understood that one or more additional stator segments of one or both of the types illustrated and / or one or more additional segments of a different type (such as those described herein) may be employed in other embodiments.

[0038] like Figure 7As shown, segment 702 and segment 704 can each include one or more windings 706. In some implementations, windings 706 of segment 702 can be electrically isolated from windings 706 of segment 704 and have significantly different electrical characteristics than windings 706 of segment 704. In the illustrated example, for example, segment 702 includes windings 706a, 706b, and 706c for three respective phases, wherein the windings for each such phase form a total of four turns, while segment 704 includes windings 706d, 706e, and 706f for three respective phases, wherein the windings for each such phase form a total of two turns.

[0039] Where a "Y" configuration is used (e.g., according to Fig. 8A ) connects windings 706a, 706b, 706c of segment 702 to terminals 406a, 406b, 406c, two of windings 706 will be seen between each corresponding pair of terminals 406a, 406b, 406c. Figure 8B ) connects the windings 706a, 706b, 706c of the segment 702 to the terminals 406a, 406b, 406c, each corresponding pair of terminals 406a, 406b, 406c will see one winding 706 connected in parallel with the combination of the two other windings 706 connected in series. In embodiments where the windings 706a, 706b, 706c of the segment 702 are connected to three separate pairs of terminals (e.g., as per Figure 8C ) embodiment, each corresponding pair of terminals 406a, 406b, 406c will only see one of the windings 706.

[0040] Similarly, in the case where a "Y" configuration is used (e.g., according to Fig. 8A ) connects windings 706d, 706e, 706f of section 704 to terminals 406d, 406e, 406f, two of windings 706 will be seen between each corresponding pair of terminals 406d, 406e, 406f. Figure 8B ) connects the windings 706d, 706e, 706f of the section 704 to the terminals 406d, 406e, 406f, each corresponding pair of the terminals 406d, 406e, 406f will see one winding 706 connected in parallel with the combination of the two other windings 706 connected in series. In an embodiment where the windings 706d, 706e, 706f of the section 704 are connected to three pairs of terminals separately (e.g., according to Figure 8C) embodiment, each corresponding pair of terminals 406d, 406e, 406f will only see one of the windings 706.

[0041] In any of the above terminal configurations, the flux linkage about the rotor magnets as observed between a given set of terminals will depend on the area swept by the turns of the winding 706 observed by these terminals, and the amount of flux from the rotor captured by these areas. Therefore, with any such terminal configuration, the flux linkage achieved by the winding 706 of segment 702 as seen between a given pair of terminals 406 of segment 702 will be significantly different from the flux linkage achieved by the winding 706 of segment 704 as seen between a given pair of terminals 406 of segment 704. The different electrical characteristics of the windings 706 of the two stator segments 702, 704 can allow the respective stator segments 702, 704 to be configured to achieve optimal performance under significantly different operating conditions, such as significantly different torques and speeds. In this way, the same magnetic structure and components can be used to rely on the stator segments 702, 704 for energy conversion under complementary operating conditions for which they are designed.

[0042] like Figure 7 As illustrated in , segment 702 may include multiple terminals (e.g., terminals 406a, 406b, and 406c) that may be connected to controller 118a, and segment 704 may similarly include multiple terminals (e.g., terminals 406d, 406e, and 406f) that may be connected to controller 118b. For example, controllers 118a, 118b may each include: a set of switches, such as metal oxide semiconductor field effect transistor (MOSFET) switches, and control circuits configured to selectively open and control these switches to implement the functions described herein. Figure 7 Also shown, in some implementations, the controller 118a may also be connected to a power supply (or energy storage unit) 708a, and the controller 118b may also be connected to a power supply (or energy storage unit) 708b. In some implementations, the power supply (or energy storage unit) 708a may be separate from the power supply (or energy storage unit) 708b. In other implementations, the power supply (or energy storage unit) 708a may be the same component as the power supply (or energy storage) unit 708b.

[0043] In an implementation where the controller 118a is connected to a power supply, the controller 118a may selectively cause multiple phases of the electrical signal to be applied to windings 706a, 706b, and 706c of the segment 702. Similarly, in an implementation where the controller 118b is connected to a power supply, the controller 118b may selectively cause multiple phases of the electrical signal to be applied to windings 706d, 706e, and 706f of the segment 704. In an implementation where the controller 118a is connected to an energy storage unit, the controller 118a may instead regulate the supply of power from windings 706a, 706b, and 706c to the energy storage unit 708a. Similarly, in an implementation where the controller 118b is connected to an energy storage unit, the controller 118b may instead regulate the supply of power from windings 706d, 706e, and 706f to the energy storage unit 708b. In some such implementations, one or more stator segments (e.g., segment 702) may be configured as a motor including windings 706 having a first set of electrical characteristics, and another segment (e.g., segment 704) may be configured as a generator including windings 706 having a second, different set of electrical characteristics. In other implementations, one or more stator segments (e.g., segment 702) may be configured as a motor including windings 706 having a first set of electrical characteristics, and another segment (e.g., segment 704) may also be configured as a motor, but may include windings 706 having a second, different set of electrical characteristics. In still other implementations, one or more stator segments (e.g., segment 702) may be configured as a generator including windings 706 having a first set of electrical characteristics, and another segment (e.g., segment 704) may also be configured as a generator, but may include windings 706 having a second, different set of electrical characteristics.

[0044] As described above, in some embodiments, a given stator structure (e.g., one of the stator segments 702, 704) may include windings 706 for multiple electrical phases, and energy may be transferred between these windings 706 and an external circuit via terminals 406 located on the stator structure. Figure 7 In the example motor 700 shown, the stator segment 702 includes three terminals 406a, 406b and 406c, which are electrically connected to the three windings 706a, 706b and 706c for the corresponding phases supported by the stator segment 702, and the stator segment 704 includes three terminals 406d, 406e and 406f, which are electrically connected to the three windings 706d, 706e and 706f for the corresponding phases supported by the stator segment 704.

[0045] FIG. 8A to FIG. 8CThree possible schemes for driving (or receiving power from) three windings (ie, windings W1 , W2 , and W3 ) through a plurality of terminals are illustrated. Fig. 8A and Figure 8B The illustrated solution allows driving (or receiving power from) three windings for the respective phases (i.e. windings W1, W2 and W3) using only three terminals (i.e. terminals T1, T2 and T3). Figure 8C The illustrated scheme requires additional terminals (eg, terminals T1 , T2 , T3 , T4 , T5 , and T6 ) to drive (or receive power from) the three windings for the respective phases (ie, windings W1 , W2 , and W3 ). Fig. 8A The connection configuration shown is commonly referred to as a "Y" configuration. Figure 8B The connection configuration shown is generally referred to as a "delta" configuration. Any of the above configurations can be used to connect Figure 7 The windings 706 and terminals 40 of the respective stator segments 702, 704 are shown interconnected, wherein if a Figure 8C configuration, additional terminals are provided.

[0046] For motor 700( Figure 7 In an implementation as shown in FIG. 1 , where a given stator segment 702, 704 includes only three terminals to drive three windings (or receive power from these three windings), at least the following four configurations are possible: (1) Fig. 8A The windings W1, W2 and W3 in the Figure 7 The three phase windings 706a, 706b and 706c of the stator segment 702 are shown, and Fig. 8A The terminals T1, T2 and T3 in Figure 7 The three terminals 406a, 406b and 406c of the stator segment 702 are shown; (2) Fig. 8A The windings W1, W2 and W3 in the Figure 7 The three phase windings 706d, 706e and 706f of the stator segment 704 are shown, and Fig. 8A The terminals T1, T2 and T3 in Figure 7 The three terminals 406d, 406e and 406f of the stator segment 704 are shown; (3) Figure 8B The windings W1, W2 and W3 in the Figure 7 The stator segment 702 is shown with three phase windings 706a, 706b and 706c, and Figure 8B The terminals T1, T2 and T3 in Figure 7 The three terminals 406a, 406b and 406c of the stator segment 702 are shown; or (4) Figure 8B The windings W1, W2 and W3 in the Figure 7 The three phase windings 706d, 706e and 706f of the stator segment 704 are shown, and Figure 8B The terminals T1, T2 and T3 in Figure 7 Three terminals 406d, 406e, and 406f of stator segment 704 are shown.

[0047] In any of the above configurations, it will be appreciated that, due to the different winding configurations (e.g., different numbers of turns per winding) of the stator segments 702, 704, the values ​​of various electrical characteristics (e.g., resistance, flux linkage, etc.) between any two of the terminals 406a, 406b, and 406c of the stator segment 702 measured when the terminals are not connected to an external circuit will be significantly different from the values ​​of the same electrical characteristics between any two of the terminals 406d, 406e, and 406f of the stator segment 704 also measured when the terminals are not connected to an external circuit. As used herein, a difference is considered "significant" if the difference is greater than what would be expected due to standard manufacturing tolerances.

[0048] Fig. 9 A second example implementation of a planar axial flux machine 900 is shown, the planar axial flux machine 900 comprising a Figures 4 to 6 There are many different stator construction types described. Fig. 9 Only two stator segments 902, 904 are shown, but as previously mentioned, it should be understood that one or more additional stator segments of one or both of the illustrated types and / or one or more additional segments of different types may be employed in other implementations. Figure 7 The same situation, Fig. 9 The upper rotor assembly 108 a is not depicted in FIG. 9 so that the two example stator segments 902 , 904 included in the electric machine 900 can be clearly seen.

[0049] As shown, the stator section 902 of the motor 900 may be constructed similar to Figure 7Stator segment 702 (or stator segment 704) is shown, wherein stator segment 702 (or stator segment 704) can have one or more windings 706 connected to controller 118 through one or more terminals 406, and wherein controller 118 can be connected to power supply (or energy storage unit) 708, so that segment 902 can operate in motor mode or generator mode. However, segment 904 of motor 900 can be a conductive sheet material (e.g., aluminum or copper) positioned in a gap within the active area of ​​motor 900 so that eddy currents can be generated when the rotor rotates, thereby causing a drag on the rotor that increases as a function of rotor speed. As used herein, the term "conductive sheet" is meant to refer to any conductive structure having a planar area so that eddy currents can be introduced into the structure, and is thus intended to include conductive planar structures with holes or other discontinuities (e.g., planar mesh structures) as well as conductive planar structures lacking such discontinuities, such as continuous aluminum sheets or copper sheets.

[0050] Advantageously, the drag introduced by the segments 904 can be selectively supplemented or selectively offset by appropriate operation of the controller 118, thereby allowing the motoring or generator behavior of the segments 902 to fine-tune the drag level applied to the rotor of the motor 900. The combination of the stator segments 902 and the stator segments 904 in such a structure can thus operate as an eddy current damper, achieving programmable dynamics through the motoring or generator action of the stator 902. In some implementations, the overall drag coefficient of such a damper can be additionally or alternatively varied by adjusting the degree to which the stator segments 904 protrude into the gap of the motor 900. The motor 900 may find useful application in scenarios where an adjustable resistance level is desired, such as for a stationary bicycle or other exercise equipment.

[0051] Fig.10 is a partial cutaway view showing a third example implementation of a planar axial flux machine 1000 including a plurality of different stator structure types. Again, Fig.10 The upper rotor assembly 108a is not depicted in the figure so that the different stator structure types included in the motor 1000 can be clearly seen. Fig.10 As shown, the motor 1000 may include Fig. 9 1000 is similar to motor 900 in that the controller 118 can operate the section 1002 in either a motor mode or a generator mode. However, the motor 1000 is similar to motor 900 ( Fig. 91000) in that the motor includes an annular sheet 1004 of conductive material (e.g., aluminum or copper) that extends over the entire active area of ​​the motor 1000, including the area below the segment 1002, for example, on a different layer than the windings 706 of the segment 1002. Similar to the segment 904 of the motor 900, when the rotor of the motor 1000 rotates, eddy currents may be generated within the annular sheet 1004 of the motor 1000, thereby causing a drag force on the rotor that increases as a function of the rotor speed. Similar to the motor 900, the drag force introduced by the annular conductive sheet 1004 may be selectively supplemented or selectively offset by appropriate operation of the controller 118, thereby allowing the motor behavior or generator behavior of the segment 1002 to fine-tune the level of drag force applied to the rotor of the motor 1000.

[0052] Despite Fig.10 Only one segment 1002 is shown in FIG. 1 , but it should be understood that one or more additional stator segments 1002 and / or one or more additional segments of a different type (such as those described herein) may be employed in other implementations.

[0053] Fig.11An example of a planar axial flux motor 1100 having a novel segment configuration is shown, which can be employed alone or with additional or different one or more segment structures. As shown, the motor 1100 can include a segment 1102, which includes one or more windings 1104 connected to a controller 1106 via two or more terminals 1108. For example, the controller 1106 can include: one or more switches, such as MOSFET switches, and control circuits configured to selectively open and control such switches to achieve the functions described herein. As also shown, in some implementations, the controller 1106 can also be connected to one or more dissipative elements 1110 (e.g., one or more resistors). In some implementations, the switch of the controller 1106b can be selectively closed to connect the dissipative elements between a pair of terminals 1108 connected to respective ends of the winding 1104. By interconnecting the ends of windings 1104 in this manner, the movement of the rotor can cause eddy currents to circulate through windings 1104 and dissipative elements 1110, thereby creating a drag on the rotor of motor 1100 that varies as a function of rotor speed, similar to the behavior of conductive sheets 904, 1004 described above. The varying value of dissipative elements 1110 can allow the magnitude of such drag to be adjusted. Thus, in some implementations, the switches of controller 1106 can be opened and closed rapidly at different rates to adjust the average value of the resistance observed between terminals 1108. In some implementations, dissipative elements 1110 can be omitted, and the switches of controller 1106 can instead be interconnected directly to terminals 1108 to achieve similar results without the additional power dissipation provided by resistors or the like.

[0054] In some implementations, multiple windings 1104 may be employed on one or more such sections 1102, and the controller 1106 may selectively establish connections (either directly or through one or more dissipative elements 1110) between pairs of terminals electrically connected to the ends of respective windings 1104. In such embodiments, by varying the number of respective windings 1104 for which such connections are established, the amount of drag applied to the rotor of the motor 1100 may additionally or alternatively be adjusted. Although in Fig.11 Only one segment 1102 is shown in FIG. 1 , but it should be understood that one or more additional stator segments 1102 and / or one or more additional segments of a different type (such as those described herein) may be employed in other implementations.

[0055] Fig.12 A fourth example implementation of a planar axial flux machine 1200 is shown, the planar axial flux machine 1200 comprising a Figures 4 to 6 As in the other examples, the Fig.12 The upper rotor assembly 108a is not depicted in the figure so that the two example stator segments 1202, 1204 included in the motor 1200 can be clearly seen. As shown, the motor 1200 can include the following: (A) segment 1202 and associated circuits 1106, 1110, segment 1202 and associated circuits 1106, 1110 and motor 1100 ( Fig.11 (B) stator segment 1204 and associated circuits 118, 708, stator segment 1204 and associated circuits 118, 708 and Figure 7 The stator segment 702 (or stator segment 704) shown is similar. In some implementations, the stator segment 1204 and associated circuits 118, 708 can operate as a motor or generator, and the stator segment 1202 can operate as a controllable brake (or other resistance generating component) for the rotor of the motor 1200. Although in Fig.12 Only two stator segments 1202, 1204 are shown, but as previously described, it should be understood that one or more additional stator segments of one or both of the illustrated types and / or one or more additional segments of different types may be employed in other implementations.

[0056] like Fig.12 As shown, the segments 1202 and 1204 may each include one or more windings 706, 1104. In some implementations, the windings 1104 of the segment 1202 may be electrically isolated from the windings 706 of the segment 1204 and have significantly different electrical characteristics than the windings 706 of the segment 1204. In the illustrated example, for example, the segment 1204 includes windings 706a, 706b, and 706c for three respective phases, wherein the windings for each such phase form a total of four turns, while the segment 1202 includes only one winding 1104 forming a total of eight turns.

[0057] Where a "Y" configuration is used (e.g., according to Fig. 8A ) connects windings 706a, 706b, 706c of segment 1204 to terminals 406a, 406b, 406c, two of windings 706 will be observed between each corresponding pair of terminals 406a, 406b, 406c. Figure 8B) connects the windings 706a, 706b, 706c of the section 1204 to the terminals 406a, 406b, 406c, each corresponding pair of the terminals 406a, 406b, 406c will see a winding 706 connected in parallel with the combination of the two other windings 706 connected in series. In embodiments where the windings 706a, 706b, 706c of the section 1204 are connected to three separate pairs of terminals (e.g., as per Figure 8C ) embodiment, each corresponding pair of terminals 406a, 406b, 406c will only observe one winding 706 of the windings 706.

[0058] In any of the above terminal configurations, the flux linkage about the rotor magnets as observed between a given set of terminals will depend on the area swept by the turns of winding 706 as observed by those terminals, and the flux from the rotor captured by those areas. Thus, with any such terminal configuration, the flux linkage achieved by winding 1104 of segment 1202 as observed between terminals 1206a, 1206b will be significantly different from the flux linkage achieved by winding 706 of segment 1204 as observed between corresponding pairs of terminals 406. Thus, the different electrical characteristics of windings 1104, 706 of the two stator segments 1202, 1204 can allow the respective stator segments to be configured to perform their respective functions (e.g., motor / generator action and braking action) in an optimal manner.

[0059] With about Figure 7 In a manner similar to the disclosed embodiments, it will be appreciated that, due to the different winding configurations of the stator segments 1202, 1204 (e.g., different numbers of turns in each winding), the values ​​of various electrical characteristics (e.g., resistance, flux linkage, etc.) measured between two terminals 1206a, 1206b of the stator segment 702 when these terminals are not connected to an external circuit will be significantly different from the values ​​of these same electrical characteristics measured between any two of the terminals 406a, 406b, and 406c of the stator segment 1204 when these terminals are not connected to an external circuit.

[0060] Fig.13 A fifth example implementation of a planar axial flux machine 1300 is shown, the planar axial flux machine 1300 comprising a Figures 4 to 6 The various stator construction types described. Again, Fig.13The upper rotor assembly 108a is not depicted in the figure so that the two example stator structures 1302, 1304 included in the motor 1300 can be clearly seen. As shown, the motor 1300 can include the following: (A) stator segments 1302 and associated circuits 1106, 1110, stator segments 1302 and associated circuits 1106, 1110 and motor 1100 ( Fig.11 1300); and (B) a stator segment 1304 comprising a conductive sheet material (e.g., aluminum or copper) positioned in a gap within the active area of ​​the motor 1300 such that eddy currents may be generated as the rotor rotates, thereby causing a drag force on the rotor that increases as a function of rotor speed. In some implementations, the stator segment 1302 and associated circuitry 1106, 1110 may be operable to selectively supplement the drag force applied to the rotor of the motor 1300 via the stator segment 1304, thereby allowing the level of drag force applied to the rotor of the motor 1300 to be fine-tuned. Although in Fig.13 Only two stator segments 1302, 1304 are shown, but as previously described, it should be understood that one or more additional stator segments of one or both of the illustrated types and / or one or more additional segments of different types may be employed in other implementations.

[0061] Fig.14 is a partial cutaway view showing a sixth example implementation of a planar axial flux machine 1400 including a plurality of different stator structure types. Fig.14 The upper rotor assembly 108a is not depicted in the figure so that the two example stator structures 1402, 1404 included in the motor 1300 can be clearly seen. As shown, the motor 1400 can include the following two: (A) stator segments 1402 and associated circuits 1106, 1110, stator segments 1402 and associated circuits 1106, 1110 and motor 1100 ( Fig.11 (B) an annular sheet 1404 of conductive material (e.g., aluminum or copper) positioned in a gap within the active area of ​​the motor 1400 so that eddy currents can be generated as the rotor rotates, thereby generating a drag on the rotor that increases as a function of rotor speed.

[0062] With motor 1300( Fig.13), in some implementations, the stator segment 1402 and associated circuits 1106, 1110 can be operated to selectively supplement the resistance applied to the rotor of the motor 1300 via the annular conductive sheet 1404, thereby allowing the resistance level applied to the rotor of the motor 1400 to be fine-tuned. Fig.14 Only two stator structure types are shown in FIG. 1 , but as previously described, it should be understood that one or more additional stator structures of one or both of the illustrated types and / or one or more additional stator structures of different types may be employed in other implementations.

[0063] The advantages of the various stator designs described herein are numerous. For some of the above embodiments, similar performance can be achieved by mechanically combining a conventional motor with a conventional damper. Such a motor and damper solution would require thermal solutions, multiple axes, and mechanical integration. Using a particular stator motor configuration among the stator motor configurations described herein would eliminate these considerations.

[0064] As for the other example embodiments described above, similar performance can be obtained by connecting a controllable eddy current brake on the same shaft as the motor. Again, such a solution will increase system complexity and cost. In particular, additional magnetic structures will be required for the braking feature. For example, electromagnets that require an external power supply or additional magnets that are used only when braking. Using a specific stator motor configuration in the stator motor configuration described herein will also eliminate these considerations.

[0065] With respect to still other example embodiments described above, similar performance can be obtained by connecting two or more motors designed for different operating states to the same shaft. Such a design will be accompanied by various mechanical challenges. Using a particular stator motor configuration among the stator motor configurations described herein will allow the motor sections to share the same magnetic circuit, rotor material, and bearings. This will result in a simpler, more economical design.

[0066] Embodiments of electric machines of the type described herein correspond to a variety of application areas, examples of which include but are not limited to the following applications.

[0067] One application is in therapeutic or athletic equipment. Here, the role of the motor is to resist the force of the person, so as to absorb the force or convert some of the force into electricity while emulating the target activity. Such activities can include the force and inertia characteristics of weightlifting, the resistance of rowing, the variable resistance associated with cycling, etc. The power required to imitate these activities can be achieved by, for example, feedback control of a conventional servo motor combined with an energy storage and dissipation mechanism. Using a specific stator motor configuration described in this article will allow the motor action to be combined with a dissipative stator element, with advantages including reduced overall system cost and complexity.

[0068] In some implementations, multiple motor stator structures can be combined additionally or alternatively in the gap to meet a wide range of requirements within the same motor. For example, a motor stator section designed for low torque high speed operation can be combined with a motor stator section for high torque low speed operation.

[0069] In some implementations, one or more motor / generator sections may additionally or alternatively be combined with a section dedicated to inductive braking under active control. In this case, for example, a direct drive wind turbine generator (one section) may have a braking mechanism (brake section) that regulates turbine speed in high wind conditions. In similar motor applications, the brake section may provide an emergency shaft stop function.

[0070] The following paragraphs (P1) to (P8) describe examples of the inventive concepts disclosed herein:

[0071] (P1) A planar stator for an axial flux motor (which has a rotor including one or more magnets, wherein the one or more magnets generate a first magnetic flux substantially parallel to the rotation axis of the rotor in an active region within a gap of the axial flux motor) may include: at least a first terminal, a second terminal, a third terminal and a fourth terminal, each terminal being suitable for connecting to an electrical circuit located outside the planar stator; at least one first winding, the at least one first winding being arranged to be positioned within the active region, the at least one first winding having a first end and a second end electrically connected to the first terminal and the second terminal, respectively, wherein an electrical characteristic between the first terminal and the second terminal measured when the first terminal and the second terminal are not connected to the electrical circuit has a first value; and at least one second winding, the at least one second winding being arranged to be positioned within the active region, the at least one second winding being electrically isolated from the at least one first winding and having a third end and a fourth end electrically connected to the third terminal and the fourth terminal, respectively, wherein an electrical characteristic between the third terminal and the fourth terminal measured when the third terminal and the fourth terminal are not connected to the electrical circuit has a second value significantly different from the first value.

[0072] (P2) The planar stator can be constructed as described in paragraph (P1), wherein at least one first winding can be disposed on a first stator segment and at least one second winding can be disposed on a second stator segment, the second stator segment being angularly offset from the first stator segment relative to the axis of rotation.

[0073] (P3) The planar stator can be constructed as described in paragraph (P1) or paragraph (P2), wherein at least one first winding can include a first winding and at least one additional winding; the circuit can include a power supply; the first winding can be constructed to support a first phase from the power supply; and at least one additional winding can be constructed to branch off at least one additional phase from the power supply, such that a peak value of a second magnetic flux generated by a combination of the first winding and the at least one additional winding follows an arcuate path relative to the axis of rotation.

[0074] (P4) The planar stator can be constructed as described in any of paragraphs (P1) to (P3), wherein the electrical characteristic can include resistance, and a first resistance between the first terminal and the second terminal measured when the first terminal and the second terminal are not connected to the circuit can be at least fifty percent greater than a second resistance between the third terminal and the fourth terminal measured when the third terminal and the fourth terminal are not connected to the circuit.

[0075] (P5) The planar stator can be constructed as described in any of paragraphs (P1) to (P4), wherein the electrical characteristics can include flux linkage about a first magnetic flux, and a first flux linkage between at least one first winding and the first magnetic flux observed between the first terminal and the second terminal can be at least fifty percent greater than a second flux linkage between at least one second winding and the first magnetic flux observed between the third terminal and the fourth terminal.

[0076] (P6) The planar stator can be constructed as described in any of paragraphs (P1) to (P5), wherein the circuit may include a first controller configured to selectively connect the first terminal and the second terminal to a power source so that during at least a first operating mode of the axial flux motor, at least one first winding generates a second magnetic flux substantially parallel to the axis of rotation.

[0077] (P7) The planar stator can be constructed as described in any of paragraphs (P1) to (P6), wherein the circuit may also include a second controller configured to selectively connect the third terminal and the fourth terminal to a power source so that during at least a second operating mode of the axial flux motor, at least one second winding generates a third magnetic flux substantially parallel to the axis of rotation.

[0078] (P8) The planar stator can be constructed as described in any of paragraphs (P1) to (P7), and can also include at least one switch configured to be selectively closed to establish an electrical connection between the third terminal and the fourth terminal when at least one second winding is not connected to an external power supply.

[0079] (P9) The planar stator may be constructed as described in paragraph (P8), wherein at least one switch may be configured to establish an electrical connection between the third terminal and the fourth terminal via at least one dissipative element.

[0080] (P10) The planar stator can be constructed as described in paragraph (P8) or paragraph (P9), wherein the circuit can also include a second controller configured to adjust at least one switch to control the time-averaged conduction rate between the third terminal and the fourth terminal.

[0081] (P11) The planar stator can be constructed as described in any of paragraphs (P1) to (P10), wherein the circuit may also include a second controller configured to selectively connect the third terminal and the fourth terminal to the energy storage element so that during at least one second operating mode of the axial flux motor, the energy storage element receives electricity generated by the second winding in response to rotation of the rotor.

[0082] (P12) The planar stator can be constructed as described in any of paragraphs (P1) to (P11), wherein the circuit may also include a first controller configured to selectively connect the first terminal and the second terminal to an energy storage element so that during at least a first operating mode of the axial flux motor, the energy storage element receives electricity generated by the first winding in response to rotation of the rotor.

[0083] (P13) The planar stator can be constructed as described in any of paragraphs (P1) to (P12), wherein the circuit may also include a second controller configured to selectively connect the third terminal and the fourth terminal to the energy storage element so that during at least a second operating mode of the axial flux motor, the energy storage element receives electricity generated by the second winding in response to rotation of the rotor.

[0084] (P14) The planar stator can be constructed as described in any of paragraphs (P1) to (P13), and can also include at least one switch configured to be selectively closed to establish an electrical connection between the first terminal and the second terminal when at least one first winding is not connected to an external power source.

[0085] (P15) The planar stator can be constructed as described in paragraph (P14), wherein at least one switch can be configured to establish an electrical connection between the first terminal and the second terminal through at least one dissipative element.

[0086] (P16) The planar stator can be constructed as described in paragraph (P14) or paragraph (P15), wherein the circuit can also include a second controller configured to adjust at least one switch to control the time-averaged conduction rate between the first terminal and the second terminal.

[0087] (P17) A planar stator for an axial flux motor (which has a rotor including one or more magnets, wherein the one or more magnets generate a first magnetic flux substantially parallel to the rotation axis of the rotor in an active region within a gap of the axial flux motor) may include: a first conductive sheet, which is arranged to be positioned within the active region so that eddy currents generated within the first conductive sheet exert resistance on the rotor; and at least a first winding, which is arranged to be positioned within the active region, and has at least a first terminal and a second terminal electrically connected to respective ends of the first winding.

[0088] (P18) The planar stator can be constructed as described in paragraph (P17) and can also include a controller configured to selectively connect the first terminal and the second terminal to a power source so that during at least a first operating mode of the axial flux motor, the first winding generates a second magnetic flux substantially parallel to the axis of rotation.

[0089] (P19) The planar stator can be constructed as described in paragraph (P17) or paragraph (P18) and can also include a controller configured to selectively connect the first terminal and the second terminal to an energy storage element such that during at least a first operating mode of the axial flux motor, the energy storage element receives electrical power generated by the first winding in response to rotation of the rotor.

[0090] (P20) The planar stator can be constructed as described in any of paragraphs (P17) to (P19), and can also include at least one switch configured to be selectively closed to establish an electrical connection between the first terminal and the second terminal when the first winding is not connected to an external power supply.

[0091] (P21) The planar stator can be constructed as described in paragraph (P20), wherein at least one switch can be configured to selectively establish an electrical connection between the first terminal and the second terminal through at least one dissipative element.

[0092] (P22) The planar stator may be constructed as described in paragraph (P20) or paragraph (P21), and may further include a controller configured to adjust at least one switch to control a time-averaged conductance between the first terminal and the second terminal.

[0093] (P23) A planar stator for an axial flux motor (having a rotor including one or more magnets, wherein the one or more magnets generate a first magnetic flux substantially parallel to the rotation axis of the rotor in an active region within a gap of the axial flux motor) may include: at least a first winding, the first winding being arranged to be positioned within the active region, the first winding having at least a first terminal and a second terminal electrically connected to respective ends of the first winding; and at least one switch, the at least one switch being configured to be selectively closed to establish an electrical connection between the first terminal and the second terminal when the first winding is not connected to an external power supply.

[0094] (P24) The planar stator can be constructed as described in paragraph (P23), wherein at least one switch can also be constructed to establish an electrical connection between the first terminal and the second terminal through at least one dissipative component.

[0095] (P25) The planar stator may be constructed as described in paragraph (P23) or paragraph (P24), and may first include a controller configured to adjust at least one switch to control a time-averaged conductance between a first terminal and a second terminal.

[0096] (P26) An axial flux electric machine having at least two planar stator sections arranged around a rotational axis, wherein the planar stator sections are different and at least one stator section is a printed circuit stator capable of producing motor action under appropriate control.

[0097] (P27) An electric machine as described in paragraph (P26), wherein at least one stator segment is a printed circuit stator capable of producing motor action, and at least one stator segment is a conductive material board.

[0098] (P28) An electric machine as described in paragraph (P27), wherein the conductive material plate can be moved radially into or out of the gap.

[0099] (P29) An electric motor as described in any of paragraphs (P26) to (P28), wherein at least one stator segment is a printed circuit stator capable of producing motor action, and at least one stator segment is a printed circuit eddy current brake capable of operating under external control.

[0100] (P30) An electric machine as described in any of paragraphs (P26) to (P29), wherein the planar stator segments are interchangeable.

[0101] (P31) An electric machine as described in any of paragraphs (P26) to (P30), wherein at least one stator segment and at least one conductive plate are arranged around the rotation axis.

[0102] (P32) An electric machine as described in any one of paragraphs (P26) to (P31), wherein the conductive plate is constructed and arranged to be adjustable in the radial direction to enter or leave the gap.

[0103] (P33) An electric machine as described in any of paragraphs (P26) to (P32), wherein the conductive plates and the stator segments are configured to be interchangeable.

[0104] Having thus described several aspects of at least one embodiment, it will be appreciated that various modifications, alterations, and improvements will readily occur to those skilled in the art. Such alterations, alterations, and improvements are intended to be a part of this disclosure and are intended to fall within the spirit and scope of this disclosure. Therefore, the foregoing description and accompanying drawings are intended only as examples.

[0105] The various aspects of the present disclosure may be used alone, in combination, or in various arrangements not specifically discussed in the previously described embodiments, and are therefore not limited in the present application to the details and arrangements of the components set forth in the previous description or illustrated in the accompanying drawings. For example, the various aspects described in one embodiment may be combined in any manner with the various aspects described in other embodiments.

[0106] In addition, the disclosed aspects can be implemented as a method, examples of which have been provided. The actions performed as part of the method can be ordered in any suitable manner. Therefore, embodiments can be constructed in which the actions are performed in a different order than that illustrated, and although some actions are shown as sequential actions in illustrative embodiments, embodiments can also include performing some actions simultaneously.

[0107] The use of ordinal terms such as "first", "second", "third", etc. to modify claim elements in the claims does not itself imply any priority, precedence or order of one claim element over another element or the temporal order of the actions of performing the method, but is merely used as a marker to distinguish one claim element with a particular name from another element with the same name (but using ordinal terms) to distinguish the claim elements.

[0108] In addition, the words and terms used herein are for descriptive purposes and should not be considered limiting. The use of "includes," "comprising," or "having," "containing," "involving," and variations thereof herein is intended to include the items listed thereafter and their equivalents as well as additional items.

Claims

1. A device comprising: a rotor configured to rotate about a rotation axis, the rotor comprising one or more magnets that generate a first magnetic flux in an active region; a first conductive sheet positioned within the active region such that eddy currents generated within the first conductive sheet exert drag on the rotor; a stator structure comprising at least a first winding positioned within the active area; at least a first switch constructed and arranged to regulate the flow of current through the first winding; A control circuit is configured to adjust the manner in which the first switch is operated to selectively supplement or selectively counteract the resistance on the rotor.

2. The apparatus according to claim 1, wherein: The stator structure has a generally planar shape; and The apparatus is an axial flux machine in which the one or more magnets generate the first magnetic flux substantially parallel to the axis of rotation within a gap in which the stator structure is located.

3. The apparatus according to claim 2, wherein: The control circuit is configured to operate the first switch to selectively couple the first terminal and the second terminal of the first winding to a power source so that during at least a first operating mode of the axial flux machine, the first winding generates a second magnetic flux substantially parallel to the rotation axis.

4. The apparatus according to claim 2, wherein: The control circuit is configured to operate the first switch to selectively connect the first terminal and the second terminal of the first winding to an energy storage element so that during at least a first operating mode of the axial flux motor, the energy storage element receives power generated by the first winding in response to rotation of the rotor.

5. The apparatus of claim 1, wherein: The control circuit is configured to operate the first switch to selectively connect the first terminal and the second terminal of the first winding to an energy storage element so that during at least a first operating mode of the device, the energy storage element receives power generated by the first winding in response to rotation of the rotor.

6. The apparatus of claim 1, wherein: The first switch is constructed and arranged to be selectively closed to establish an electrical connection between the first terminal and the second terminal of the first winding when the first winding is not coupled to an external power source.

7. The device according to claim 6, wherein: The first switch is further constructed and arranged to selectively establish the electrical connection between the first terminal and the second terminal via at least one dissipating element.

8. The apparatus of claim 7, wherein: The control circuit is further configured to adjust the first switch to control a time-averaged conduction rate between the first terminal and the second terminal.

9. The apparatus of claim 6, wherein: The control circuit is further configured to adjust the first switch to control a time-averaged conduction rate between the first terminal and the second terminal.

10. The apparatus of claim 1, wherein: The control circuit is configured to operate the first switch to selectively couple the first terminal and the second terminal of the first winding to a power source such that the first winding generates a second magnetic flux during at least a first operating mode of the device.

11. The apparatus of claim 1, wherein: The control circuit is configured to operate the first switch to selectively connect the first terminal and the second terminal of the first winding to an energy storage element so that during at least a first operating mode of the device, the energy storage element receives power generated by the first winding in response to rotation of the rotor.

12. A method of operating a device according to any one of claims 1 to 11, the method comprising: operating the first switch in a first manner using the control circuit to supplement or offset the resistance on the rotor by a first amount; and The first switch is operated in a second manner using the control circuit to supplement or offset the resistance on the rotor by a second amount different from the first amount.

13. The method according to claim 12, further comprising: The resistance is varied by adjusting the position of the first conductive sheet relative to the active area.

14. The method according to claim 12 or 13, wherein: Operating the first switch in the first manner using the control circuit includes operating the first switch using the control circuit to selectively couple a first terminal and a second terminal of the first winding to a power source such that the first winding generates a first amount of second magnetic flux that is substantially parallel to the axis of rotation; and Operating the first switch in the second manner using the control circuit includes operating the first switch using the control circuit to selectively connect the first terminal and the second terminal to a power source so that the first winding generates a second amount of the second magnetic flux that is substantially parallel to the rotation axis, and the second amount is different from the first amount.

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