BR112021007191A2 - stator and rotor design for periodic torque requirements - Google Patents

Abstract

STATOR AND ROTOR DESIGN FOR PERIODIC TORQUE REQUIREMENTS. The present invention relates to an engine or generator which comprises a rotor and a stator, where the rotor has a axis of rotation and is configured to generate a first magnetic flux parallel to the axis of rotation, the stator is configured to generate a second magnetic flux parallel to the axis of rotation, and at least one of the rotor or stator is configured to generate a flux profile magnet that is unevenly distributed over the shaft of rotation. Further described is a method that involves arranging one or more magnetic flux producing windings of a stator do not uniformly on an axis of rotation of a motor rotor or axial flow generator.

Description

Invention Patent Descriptive Report For: "STATOR AND ROTOR DESIGN FOR PERIODIC TORQUE REQUIREMENTS". Cross Reference to Related Orders

[0001] This order claims benefit under 35 U.S.C. § 119 (e) of US Interim Order Serial No. 62/754,051, entitled PLANAR

STATOR AND ROTOR DESIGN FOR PERIODIC TORQUE REQUIREMENTS, filed November 1, 2018. This application is also a continuation in part and claims benefit under 35 USC § 120 of US Patent Application Serial No. 16/378,294 entitled STRUCTURES AND METHODS FOR CONTROLLING LOSSES IN PRINTED CIRCUIT BOARDS, filed April 8, 2019, which is a continuation and claims benefit under 35 USC § 120 of US Patent Application Serial No. 16/165,745, entitled

STRUCTURES AND METHODS FOR CONTROLLING LOSSES IN PRINTED CIRCUIT BOARDS, filed October 19, 2018, and now US Patent No. 10,256,690, which is a continuation and claims benefit under 35 USC § 120 of US Patent Application No. of series 15/852,972, entitled PLANAR COMPOSITE

STRUCTURES AND ASSEMBLIES FOR AXIAL FLUX MOTORS AND GENERATORS, filed December 22, 2017, and now US Patent Serial No. 10,170,953, which claims benefit under 35 USC § 119 (e) of US Interim Application Serial No. 62/530,552, entitled STRUCTURES AND METHODS OF STACKING SUBASSEM-BLIES IN PLANAR COMPOSITE STATORS TO OBTAIN HIGHER WORKING VOLTAGES, filed July 10, 2017, which is also a continuation in part and claims benefit under 35 USC § 120 of the Order of US Patent Serial No. 15/611,359 entitled STRUCTURES AND METHODS FOR CONTROLLING LOSSES IN PRINTED CIRCUIT BOARDS, filed June 1, 2017, and now US Patent No. 9,859,763, which (A) is a continuation in part and claims benefit under 35 USC § 120 of US Patent Application No. 15/283,088 entitled STRUCTURES

AND METHODS FOR CONTROLLING LOSSES IN PRINTED CIRCUIT BOARDS, filed September 30, 2016, and now US Patent No. 9,800,109, which is a continuation in part and claims benefit under 35 USC § 120 of the US Patent Application Serial No. 15/199527, entitled STRUCTURES AND METHODS FOR THERMAL MANAGEMENT IN PRINTED CIRCUIT BOARD STATORS, filed June 30, 2016, and now US Patent No.

9,673,684, and which also claims benefit under 35 USC § 119(e) for each of (1) US Provisional Patent Application Serial No. 62/236,407 entitled STRUCTURES TO REDUCE LOSSES IN PRINTED CIRCUIT BOARD WINDINGS, filed October 2, 2015, and (2) US Provisional Patent Application Serial No. 62/236,422 entitled STRUCTURES FOR THERMAL MANAGEMENT IN PRINTED CIRCUIT BOARD STATORS, filed October 2, 2015, and (B) is a continuation in part of and claims benefit under 35 USC § 120 of US Patent Application Serial No. 15/208,452 entitled APPARATUS AND METHOD FORMING A MAGNET ASSEMBLY, filed July 12, 2016, and now US Patent No. 9,673 .688, which claims benefit under 35 USC § 119 (e) of US Provisional Patent Application Serial No. 62/275,653 entitled AXIAL FLOW MAGNETIC COMPONENT ALIGNMNET MA-CHINES WITH PLANAR WINDING GENERALLY, filed at 6 January 2016. This order is also a continuation. It does not in part and claims benefit under 35 USC § 120 of US Patent Application Serial No. 15/983,985, entitled PRE-WARPED ROTORS FOR CONTROL OF MAGNET-STATOR GAP IN AXIAL FLUX MACHINES, filed May 18, 2018 and published as US Patent Application Pub. No. US 2018/0351441, which claims benefit under 35 USC § 119 (e) for each of (1) US Provisional Patent Application Serial No. 62/515,251, entitled PRE- WARPED ROTORS FOR CONTROL OF MAGNET-STATOR GAP IN AXIAL FLUX MACHINES, filed June 5, 2017, and (2) US Provisional Patent Application Serial No. 62/515,256 entitled AIR CIRCULATION IN AXIAL FLUX MACHINES, filed 5 of June 2017. The contents of each of the foregoing applications, publications, and patents are hereby incorporated by reference, in their entirety, for all purposes.

[0002] Permanent magnet axial flow motors and generators described by various patents, including US Patent No. 7,109,625 ("the '625 patent"), feature a generally planar printed circuit board (PCS) stator disposed between magnets having alternating north-south poles. These printed circuit board stators, when supported on the fixed structure of the stator's outer edge, have a hole through which the shaft connecting the rotors passes. An alternative modality is to swap the roles of the inner and outer radius, which results in a situation where the inner radius of the stator is supported and the rotor surrounds the stator. The shaft is effectively moved to the outer radius in this configuration, sometimes called a "brushless DC electric motor" (outrunner). Brief Description of Drawings

[0003] Objects, aspects, characteristics and advantages of modalities described herein will become more evident from the following detailed description, the appended claims and the appended Figures in which similar reference numerals identify similar or identical elements. Reference numbers that are introduced in the descriptive report in association with a

Figure may be repeated in one or more subsequent Figures without further description in the descriptive report, in order to provide context for other features, and not all elements may be labeled in all Figures. Drawings are not necessarily to scale, instead emphasis is placed on illustrating modalities, principles and concepts. The drawings are not intended to limit the scope of the claims included herein.

[0004] Figure 1A shows an example of an axial flow motor or generator with which some aspects of the present description can be employed;

[0005] Figure 1B is an exploded view showing the components of the motor or axial flow generator shown in Figure 1A and a means for assembling said components;

[0006] Figure 2 is a conceptual diagram showing three printed circuit board stators having equal areas but different configurations;

[0007] Figure 3 is a diagram showing how multiple stator segments can be arranged for fabrication in a printed circuit board panel of standard dimensions;

[0008] Figure 4 is a diagram showing how a subset of the stator segments shown in Figure 3 will appear if they are arranged edge-to-edge on the printed circuit board shown in Figure 3;

[0009] Figure 5 shows an example of arrangement of a stator segment with respect to magnets in a rotor according to some aspects of the present description;

[0010] Figure 6 shows the same arrangement as Figure 5, but where the rotor is shown at an angle where the stator segment overlaps with a magnet section that provides peak torque;

[0011] Figure 7 shows an example of arrangement of multiple stator segments with respect to magnets in a rotor according to some aspects of the present description; and

[0012] Figure 8 illustrates a cross section of an example embodiment of an axial flow motor that is configured and integrated with a washing machine load in accordance with some aspects of the present description. summary

[0013] This summary is provided to introduce a selection of concepts in a simplified form that are 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 claims included herein.

[0014] In some of the described embodiments, a motor or generator comprises a rotor and a stator, in which the rotor has a rotation axis and is configured to generate a first magnetic flux parallel to the rotation axis, the stator is configured to generate a second magnetic flux parallel to the axis of rotation, and at least one of the rotor or stator is configured to generate a magnetic flux profile that is unevenly distributed about the axis of rotation.

[0015] In other described embodiments, a method involves arranging one or more magnetic flux producing windings of a stator non-uniformly about an axis of rotation of a rotor of a motor or axial flux generator.

[0016] In still other described embodiments, a rotor for use in a motor or generator comprises a support structure and one or more magnet segments that are supported by the support structure and which generates a first magnetic flux parallel to an axis of rotation on which the support structure rotates when mounted with a stator that generates a second magnetic flux parallel to the axis of rotation, wherein the one or more magnet segments are configured and arranged to generate a magnetic flux profile that is distributed in a manner. not uniform about the axis of rotation. Detailed Description

[0017] In existing axial flow engines or generators, such as those described in US Pat. 7,109,625; 9,673,688;

9,800,109; 9,673,684; and 10,170,953, as well as US Patent Application Publication No. 2018-0351441 A1 ("the '441 Publication"), the entire contents of each of which are incorporated herein by reference, the flow generation components magnetic stator, whether composed of a single continuous printed circuit board or several printed circuit board segments are arranged so that, at any time when the stator windings are energized with current, the peak locations of magnetic flux generated by the stator are evenly distributed with respect to the angle around the axis of rotation of the rotor. Likewise, in such machines, the rotor magnetic flux generating components, whether they are composed of a ring magnet or individual magnets arranged in pockets, are also arranged so that, at any point in time, the peak locations of magnetic flux generated by the rotor are evenly distributed with respect to the angle around the axis of rotation of the rotor. Therefore, in all these machines, at any time the machine is in operation, the peak locations of magnetic flux generated by each of the rotor and stator are evenly distributed as a function of the angle around the axis of rotation of the machine. . In other words, for each of the rotor and stator in such machines, the same angle separates each magnetic flux peak location from the next adjacent magnetic flux peak location around the axis of rotation so that the magnetic flux profile of each of the rotor and stator are evenly distributed around the axis of rotation.

[0018] Described in this document are alternative designs, with cost advantages over conventional designs for certain loads and machine configurations, in which the stator and/or rotor can instead be configured to have a flux profile magnetic that is not evenly distributed around the rotor's rotation axis. In some embodiments, for example, a stator can be configured to describe a fraction of an arc around the main axis of the machine. If such a stator segment can be located, due to the integration of the machine with the attached load, over a large radius compared to a stator of equal area evenly distributed around the same axis, the torque produced can be proportional to the increase in radius in the which segment of the stator is disposed, assuming equivalent flux in space and limits of current density in the stator. However, the cost of maintaining an equivalent flux in space for an "off-center" stator segment is an increase in magnet volume inversely proportional to the angle subtended by that segment. This is not a desirable exchange in most cases. However, in an application where peak torque is desired at a certain angle or range of shaft angles, the magnet material may be unevenly distributed with respect to the rotor, so that the stator is exposed to the density of peak magnetic flux at shaft angles where maximum torque is desired. For generator applications where the source is capable of producing periodic torque, a machine designed according to this principle can offer similar advantages.

[0019] The design of the stator and magnetic system to produce peak torque at specific angles is not limited to a stator segment and/or a concentration of magnetic material in the rotor,

although this is the simplest modality. Modalities that include one or more non-uniformly distributed stator segments and/or one or more non-uniformly distributed magnet segments can provide useful combinations of torque capacity as a function of angle. It should be appreciated that the same or similar torque capacity as a function of angle can be achieved using different combinations of one or more non-uniformly distributed stator segments and one or more non-uniformly distributed magnet segments. For example, the same or similar torque capacity as a function of angle can be achieved by swapping the distribution of the stator segments versus the rotor magnet locations. This can allow designers to offset the cost of magnetic material and stator area while achieving the same or similar torque capacity as a function of angle.

[0020] Designing a machine to produce peak torque at a given angle does not preclude continuous rotation. When continuous rotation is desired, a machine designed according to the principles described here can deliver torque in a series of pulses (at peak torque angles) that are smoothed by the moment of inertia of the attached load to provide approximately constant speed. An advantage of this design is that stator losses due to eddy currents can be zero when the stator does not overlap the magnets. Another possibility for continuous rotation is to distribute magnets so that the stator segment always sees magnet flux, but in magnitude smaller than the "peak torque" angles.

[0021] Some modalities described here can be particularly advantageous for applications where the machine radius can be significantly increased, compared to a conventional design. In these applications, a flat circuit board (PCS) stator segment disposed at a greater radius than a uniform flat circuit board stator can achieve greater peak torque per unit stator area. Also, compared to a thin annular stator at a large radius, the stator segments can be "tiled" or arranged on a standard-sized printed circuit board "panel". This can allow more efficient use of the printed circuit board material and reduce the associated machine cost.

[0022] Examples of application areas include reciprocating piston or diaphragm type pumps, which may have a periodic torque requirement. Also, for balancing purposes, these machines often include an off-center mass that can potentially be replaced by an asymmetrically designed rotor. Likewise, generators coupled to single piston motors can benefit from co-designing balance masses with magnetic materials in a stator segment-type generator. Other potential applications include washing machines or other applications where the motor or generator moves through a limited angle and periodic or "reverse" type loads.

[0023] A basic observation of the new concepts disclosed in this document can be reduced to a "staging" argument for otherwise equivalent stators or stator segments, regardless of internal organization and stator connection, based on fundamental design considerations . In a conventional annular PCS, in accordance with the description in the '625 patent, the torque can be expressed as below = ( ).

[0024] The components of this expression include integration from a first radius r1 to a second radius r2, which comprises the active area of the stator. The integral covers a complete ring by the integration limits at . The term is an element of differential area, and is the magnitude of the torque density that corresponds to the equation = . Force density is -directed by virtue of axial flow and radial current density, i.e., = ( )

[0025] Here, the force density is the product of the current density carried by the stator and the resulting magnetic flux density of the rotor magnetic circuit and the reaction of the stator in this current density. For illustration, B is considered radial. In stators designed in accordance with the '625 patent, diverging radial traces effectively introduce a 1/r decrease in the current density of the inner radius r1. A model that captures this effect is ( )= /

[0026] where is the maximum supported current density based on resource interference at a given copper weight, through size requirements and internal radius clearance. With this model, =

[0027] the current density supported by the stator depends on the number of internal pathways that can be arranged at r1, which depends on the sizes of features and associated clearances, as well as the circle at r1, and whether this circle accommodates features at a spacing that approaches the manufacturing limits. Therefore,

it is not strictly correct to consider it as a constant. For r1 = 0, for example, no path can be accommodated and e = 0. However, for motors of practical interest, it will approach a value mainly dependent on thermal considerations and clearance requirements. Taking it as a constant for comparison purposes between otherwise equivalent stators, it tends to make a conventional stator located around the central axis, with a smaller r1, appear more competitive than a stator segment at a larger radius.

[0028] The area of the stator or stator segment with angular extension is = ( − ) 2

[0029] For a conventional design stator, = 2 . For a stator segment, δ ideally corresponds to an integer number of pole pairs. For purposes of comparing stator segments and conventional designs on the basis of cost, it is reasonable to compare equal-area stators and magnet assemblies. Multiple solutions of δe exist for any one as the inner radius increases, and is considered here as the independent variable. In particular, when considering δ, the spacing of the poles over a segment need not also conform to the usual restriction of arranging the poles evenly over 2π rad, as in a conventional stator. This suggests considerable design flexibility for the segment that is not enjoyed by the conventional stator, as well as the ability to reach area A. Examples of advantages of shifting the stator area larger with compact δ include: (1) segments of the larger stator provide higher peak torque per unit area, (2) when the stator segments and magnetic material fully overlap at specific rotor angles (or angle ranges), peak torque is available, (3) there is no eddy current loss in the machine when the magnetic material and the stator do not overlap, (4) stator segments can be obtained where , and δ are such that the segments can "nested" in a printed circuit board panel, minimizing material waste and cost, and (5) peak torque per unit area (or per unit cost) increases with stator segment radius.

[0030] Given a design procedure for a prototype conventional stator with δ = 2π meeting a specific torque, designs for stator segments subtending a subset of the poles in the prototype design covering an angle δ can be "inferred to produce a torque over the range of angles where the segment fully overlaps the magnetic material. Thus, a practical design procedure for segments is to design conventional stator prototypes, where the torque requirement is increased by the ratio of the poles in the conventional stator at This procedure, while convenient, does not exploit the freedom of the segmented design, because the spacing of the poles is simultaneously restricted to the angular extent of the segment and the 2π extent of the conventional design. δ does not need to be a divisor of 2π and can therefore be optimized to meet design constraints.

[0031] Combinations of stator segments and magnetic material, concentrated at specific angles in the fixed structure and rotor, can achieve various torque capacities as a function of angle. One or more areas of the rotor can carry magnetic materials that comprise different flux densities, one or more pairs of poles, and can be distributed at various angles. There may be one or more stator segments, in the fixed structure, positioned at various angles.

[0032] Examples of motor and/or generator designs in which non-uniformly distributed stators and/or rotors, such as those disclosed herein, may be employed and are described in US Pat. 7,109,625; 9,673,688; 9,800,109;

9,673,684; and 10,170,953, as well as in U.S. Patent Application Publication No. 2018-0351441 A1 ("the '441 Publication"), which are incorporated by reference above. Illustrative examples of such machines will initially be described in connection with Figures 1A and 1B. Examples of stators and rotors with magnetic flux profiles which are non-uniformly distributed around the axis of rotation of a rotor and which can be employed in such machines will then be described in connection with Figures 2-8.

[0033] Figure 1A shows an example of a system 100 employing a flat composite stator 110 in an assembly with rotor components 104a and 104b, shaft 108, wires 114 and controller 112. An exploded view showing these components and a means for their assembly is shown in Figure 1B. The pattern of magnetic poles on the permanently magnetized portions 106a, 106b of the rotor assembly is also evident in the exploded view of Figure 1B. Figure 1A is an example of an embodiment where electrical connections 114 are made to the outer radius of the PCS 110 and the stator is mounted in a frame or box on the outer periphery. Another useful configuration, the “brushless DC electric motor (outruner)” configuration, involves mounting the stator on the inner radius, making electrical connections 114 on the inner radius, and replacing shaft 108 with an annular ring separating the rotor halves. It is also possible to configure the system with just one magnet, 106a or 106b, or to arrange multiple stators between successive magnet sets. Wires 114 can also convey rotor position information based on Hall effect readings or similar sensors mounted on the stator. Not shown, but of similar purpose, an encoder attached to shaft 108 can provide position information to controller 112.

[0034] The system 100 in Figures 1A and 1B can function as a motor or a generator, depending on the operation of the controller 112 and the components connected to the shaft 108. As a motor system, the controller 112 operates switches so that the currents in stator 110 create torque around the shaft, due to magnetic flux in space originating from magnets 104a, 104b connected to shaft 108. Depending on the design of controller 112, magnetic flux in space and/or rotor position can be measured or estimated to operate the switches to achieve torque output on shaft 108. As a generator system, a mechanically rotating power source connected to shaft 108 creates voltage waveforms at terminals 112 of the stator. These voltages can be applied directly to a load or can be rectified with a three-phase (or polyphase) rectifier inside controller 112. The implementation of rectifier 112 can be "auto-switched" using diodes in generator mode, or can be constructed using the controlled switches of the motor controller, but operated so that the shaft torque opposes the torque supplied by the mechanical source and the mechanical energy is converted to electrical energy. Thus, an identical configuration in Figure 1A can function as both generator and motor, depending on how controller 112 is operated. In addition, controller 112 can include filter components that mitigate switching effects, reduce EMI / RFI from wires 114, reduce losses, and provide additional flexibility in power supplied or delivered from the controller.

[0035] Figure 2 shows geometries of three stators 202, 204, 206 with different angular and radial extensions, but with equal area. Stators 204 and 206 differ by the inside radius. The 206 stator shows typical relative dimensions of stators as described in the '625 patent. The 204 stator is a slim annular design. In stator 204, the internal radius is increased, but a stator of these relative dimensions does not make efficient use of a "panel" of printed circuit board material. The stator 202 shows a stator segment 208, as proposed in this document, of equal area and radius equivalent to the stator 204. All else equal, in larger radii, the stators 202 and 204 would produce a higher peak torque than the stator 206 as radius increases torque arm.

[0036] Figure 3 shows the "panel formation", or packaging, of stator segments like segment 208 shown in Figure 1, in a standard-size printed circuit board panel 302. The effective utilization of panel 302 is high with the illustrated arrangement. The cost of the stator segments 208 is inversely proportional to the utilization of the panel 302.

[0037] Figure 4 shows an ineffective arrangement of segments 208 of the same size as in Figure 3 in panel 302. Although this arrangement is not practical, it does show the effective utilization of the panel that would be achieved for a conventional stator with the same internal radii and external than segments 208.

[0038] Figure 5 shows an example arrangement of a stator segment 208 with respect to magnets 502 in a rotor 504. In the illustrated example, a dense angular extension 506 of magnets 502, also referred to in this document as a "magnet area dense", in rotor 504 is provided to achieve peak torque at the angle of overlap with stator segment 208. Less dense angular extensions 508 of magnets 502, also referred to herein as "less dense magnet areas", are arranged to provide an angle-independent lower torque capability. Although not illustrated, it should be appreciated that, in some embodiments, non-magnetic elements may be added in the vicinity or less dense areas of magnet 508 to balance the weight of rotor 504 as a whole. Furthermore, it should be appreciated that, in some embodiments, an additional rotor portion (not shown) having a corresponding magnet arrangement, although of opposite polarity, may be positioned above the illustrated portion of rotor 504 so that the stator segment 208 can be positioned within a space between the two portions of rotor, with lines of magnetic flux extending in a direction parallel to the axis of rotation of the rotor between pairs of opposing magnets of opposite polarity. In addition, although not illustrated in Figure 5, it should be appreciated that stator segment 208 may include traces and/or conductive pathways, for example, disposed in one or more dielectric layers, which are configured to form windings which, when energized with current, generate magnetic flux in a direction parallel to the rotor's axis of rotation. Such windings can be configured to receive one or more phases of current from a power supply (not shown in Figure 5) and can be arranged in one or more spirals, one or more serpentine patterns, or otherwise, so as to generate such magnetic flux.

[0039] As shown in Figure 5, in some embodiments, the stator segment 208 can be held in place by an arcuate fastening member 510 to which the stator segment 208 can be fastened using one or more fasteners 512 and one or plus stator windings (not shown) segment 208 may be connected to terminals 514 associated with clamping member 510, which terminals may be connected to a controller (not shown in Figure 5), such as controller 112 discussed above in connection with Figures 1A and 1B to provide inrush current(s) for the winding(s).

[0040] Figure 6 shows the same configuration as Figure 5, but with the rotor 504 positioned at an angle where the stator segment 208 overlaps with the dense section of magnet 506 that provides peak torque.

[0041] Figure 7 shows an alternative arrangement to Figures 4 and

5. As shown, in addition to or instead of employing less dense magnet regions 508 (not shown in Figure 7) along with a dense angular span 506, the stator segments 502a-g can be arranged so that they are fully or nearly describe an annular stator with constant available torque at any angle. In some embodiments, a subset of the 502a-g stator segments can be produced smaller, can be arranged with a thicker pitch, can contain fewer winding "turns", and/or can be supplied with less energy than one or more others. 502 stator segments, so a machine with concentrated magnets can deliver angle-specific peak torque, while still providing torque capability at any angle. For example, in some embodiments, stator segment 502a may be configured, arranged, and/or energized differently than other stator segments 502b-g for that purpose.

[0042] No matter the particular arrangement of magnet(s) 502 and stator segment(s) 208 that is employed, in at least some circumstances care must be taken to ensure that at least one stator segment 208 at least partially overlaps at least one magnet 502 at each position during one revolution of rotor 504 so that rotor 504 is not "stuck" in a position where no magnetic flux from segments of a stator 208 interacts with the magnetic flux of a magnet 502.

[0043] In each of the example configurations described above, the segment(s) of stator 208 and/or magnet(s) 502 of rotor 504 are configured to have a magnetic flux profile that does not it is evenly distributed over the main rotation axis of the machine. In particular, the segment(s) of the stator 208 are arranged such that, at any point in time when the windings of the stator 504 are energized with current, the peak locations of magnetic flux generated by the stator are non-uniformly distributed. in relation to the angle about the rotation axis of the rotor. Likewise, in such machines, the magnets 502 of a rotor 504 are also arranged so that, at any point in time, the peak locations of magnetic flux generated by the rotor are evenly distributed non-uniformly with respect to the angle around the rotor rotation axis. Therefore, for each of the rotor and stator in such machines, different angles separate at least some peak magnetic flux locations from adjacent peak magnetic flux locations around the axis of rotation so that the generated magnetic flux profile because such component is not evenly distributed around the axis of rotation.

[0044] Figure 8 illustrates a cross section of an example embodiment of an axial flow motor 802 which is configured with components like those shown in Figures 5 and 6 and which is integrated with a washing machine load 804 according to some aspects of this description. As shown, a stator segment 208 of motor 802 can be secured to a housing 806 containing a washing machine bowl 808 by means of a fastener 510 and one or more fasteners 512, and the washing machine bowl 808 may be coupled in rotational mode to housing 806 by means of bearing elements 810. A rotor 504 of motor 802 can directly drive the tub of washing machine 808 by means of a shaft 812 that can be extended and/or fixedly fixed. attached to the tub of the washing machine 808. With the illustrated configuration, continuous rotation at relatively high speed and low torque in "spin" mode can be achieved using the 208 stator segment and a collection of 502 magnets arranged in a dense magnet region 506 and one or more less dense magnet regions 508, as described above in connection with Figures 5 and 6. During this mode of rotation, due to the non-uniform distribution of the rotor and stator magnetic flux profiles around the axis that of rotor rotation, as rotor 504 rotates through a range of angles relative to segment stator 208 at a substantially constant speed, the periodicity of torque produced due to the interaction between the magnetic flux generated by the rotor and the stator is irregular. The reversing action required for the “wash” mode can be a relatively low speed, high torque operating mode, where torque can be supplied at specific angles. In this case, the interaction of the stator segment 208 with the dense magnet region 506 can provide the peak torque requirement. Examples of Appliance Implementations and Methods Pursuant to the Present Description

[0045] The following paragraphs (A1) to (A14) describe examples of apparatus that can be implemented in accordance with the present disclosure.

[0046] (A1) A motor or generator may comprise a rotor having an axis of rotation and configured to generate a first magnetic flux parallel to the axis of rotation, and a stator configured to generate a second magnetic flux parallel to the axis of rotation, in that at least one of the rotor or stator is configured to generate a magnetic flux profile that is unevenly distributed about the axis of rotation.

[0047] (A2) a motor or generator can be configured as described in paragraph (A1), and the rotor can be further configured to generate a first magnetic flux profile that is non-uniformly distributed about the axis of rotation.

[0048] (A3) a motor or generator may be configured as described in paragraph (A2), and the rotor may additionally comprise one or more magnet segments non-uniformly distributed about the axis of rotation.

[0049] (A4) a motor or generator may be configured as described in paragraph (A3), and each of the one or more magnet segments may additionally have a respective surface location on which the first magnetic flux has a minimum density, and the respective surface locations may be unevenly distributed about the axis of rotation.

[0050] (A5) A motor or generator may be configured as described in any one of paragraphs (A2) through (A4), and the rotor may be additionally configured so that as the rotor rotates through a range of angles with respect to the stator at a substantially constant velocity, a periodicity of torque produced by virtue of the interaction of the first magnetic flux and the second magnetic flux is irregular.

[0051] (A6) A motor or generator can be configured as described in any one of paragraphs (A2) through (A5), and the stator can be further configured to generate a second magnetic flux profile that is non-uniformly distributed about the axis of rotation.

[0052] (A7) a motor or generator can be configured as described in paragraph (A1), and the stator can be further configured to generate a magnetic flux profile that is non-uniformly distributed about the axis of rotation.

[0053] (A8) a motor or generator may be configured as described in any one of paragraphs (A2) through (A7), and the stator may additionally comprise one or more printed circuit board segments non-uniformly distributed over the axis of rotation.

[0054] (A9) a motor or generator may be configured as described in any one of paragraphs (A2) to (A8), and the stator may additionally comprise conductive traces arranged in at least one dielectric layer to generate the second magnetic flux when energized with current.

[0055] (A10) a motor or generator can be configured as described in any of paragraphs (A2) through (A9), and the stator can be additionally configured so that at any given time when the conductive traces are energized with current, one or more locations of maximum density of the second magnetic flux are non-uniformly distributed about the axis of rotation.

[0056] (A11) a motor or generator can be configured as described in paragraph (A9) or paragraph (A10), the conductive traces are arranged in the at least one dielectric layer and coupled to a power source to generate three phases of the second magnetic flux corresponding to three phases of current emission by the power source.

[0057] (A12) a motor or generator may be configured as described in any one of paragraphs (A1) through (A11), and the stator may be additionally configured so that as the rotor rotates through a range of angles with respect to the stator at a constant speed, a periodicity of torque produced by virtue of the interaction of the first magnetic flux and the second magnetic flux is irregular.

[0058] (A13) A rotor for use in a motor or generator may comprise a support structure, and one or more magnet segments that are supported by the support structure and which generates a first magnetic flux parallel to an axis of rotation about which the support structure rotates when mounted with a stator that generates a second magnetic flux parallel to the axis of rotation, wherein the one or more magnet segments are configured and arranged to generate a magnetic flux profile that is non-distributed. uniform about the axis of rotation.

[0059] (A14) a rotor may be configured as described in paragraph A13, and the one or more magnet segments may further include at least a first magnet segment and a second magnet segment spaced apart from the first magnet segment, and the first magnet segment may include a greater number of adjacent magnets than the second magnet segment.

[0060] The following paragraphs (M1) to (M5) describe examples of methods that can be implemented according to the present description.

[0061] (M1) A method may comprise arranging one or more magnetic flux producing windings of a stator non-uniformly about an axis of rotation of a rotor of a motor or axial flux generator.

[0062] (M2) A method may be performed as described in paragraph (M1), wherein arranging the one or more magnetic flux producing windings further comprises arranging one or more printed circuit board segments including the windings non-uniformly over the axis of rotation.

[0063] (M3) A method may be performed as described in paragraph (M1) or paragraph (M2), wherein arranging the one or more printed circuit board segments may further comprise arranging the one or more circuit board segments printed so that, at any given time when the windings are energized with current, one or more locations of maximum density of the second magnetic flux are unevenly distributed about the axis of rotation.

[0064] (M4) A method may be carried out as described in any one of paragraphs (M1) to (M3), wherein the rotor may comprise magnets non-uniformly arranged about the axis of rotation.

[0065] (M5) A method may be performed as described in any one of paragraphs (M1) to (M4), wherein arranging the one or more magnetic flux producing windings may further comprise arranging the one or more producing windings of magnetic flux such that, as the rotor rotates through a range of angles with respect to the stator at a constant speed, a periodicity of torque produced by virtue of the interaction of magnetic flux generated by the rotor and the stator is irregular.

[0066] Having thus described various aspects of at least one modality, it should be appreciated that various changes, modifications and improvements will readily occur to those skilled in the art. Such changes, modifications and improvements are intended to form a part of this description and must be within the spirit and scope of the description. Therefore, the foregoing description and drawings are by way of example only.

[0067] Various aspects of the present description may be used alone, in combination, or in a variety of arrangements not specifically discussed in the embodiments described above and, therefore, are not limited in this application to the details and arrangement of components set forth in the foregoing description or illustrated in the drawings. For example, features described in one embodiment can be combined in any way with features described in other embodiments.

[0068] Furthermore, the aspects described can be incorporated as a method, of which an example has been provided. The acts performed as part of the method may be ordered in any suitable way. Therefore, modalities can be constructed in which the acts are performed in a different order than illustrated, which may include performing some acts simultaneously, although shown as sequential acts in illustrative modalities.

[0069] The use of ordinal terms such as "first", "second", "third", etc., in claims to modify a claim element does not by itself connote any priority, precedence or order of a claim element over another or the temporal order in which the acts of a method are performed, but are used only as labels to distinguish a claimed element with a given name from another element with the same name (but to use the term ordinal) to distinguish the elements of claim.

[0070] In addition, the phraseology and terminology used in this document are used for descriptive purposes and should not be considered limiting. The use of "including", "comprising" or "having", "containing", "involving" and variations thereof in this document is intended to cover the items listed below and their equivalents, as well as additional items.

Claims (20)

1. Motor or generator, characterized in that it comprises: a rotor having an axis of rotation and configured to generate a first magnetic flux parallel to the axis of rotation; and a stator configured to generate a second magnetic flux parallel to the axis of rotation; wherein at least one of the rotor or stator is configured to generate a magnetic flux profile that is unevenly distributed about the axis of rotation. 2. Motor or generator, according to claim 1, characterized in that the rotor is configured to generate a first magnetic flux profile that is non-uniformly distributed over the axis of rotation. 3. Motor or generator, according to claim 2, characterized in that the rotor comprises one or more magnet segments non-uniformly distributed over the axis of rotation. 4. Motor or generator, according to claim 3, characterized in that each of the one or more magnet segments has its respective surface location in which the first magnetic flux has a minimum density, and the respective surface locations they are unevenly distributed over the axis of rotation. 5. Motor or generator according to claim 2, characterized in that the rotor is configured so that, as the rotor rotates through a range of angles with respect to the stator at a substantially constant speed, a torque periodicity produced due to the interaction of the first magnetic flux and the second magnetic flux is irregular. 6. Motor or generator, according to claim 2, characterized in that the stator is configured to generate a second magnetic flux profile that is non-uniformly distributed over the axis of rotation. 7. Motor or generator, according to claim 1, characterized in that the stator is configured to generate a magnetic flux profile that is non-uniformly distributed over the axis of rotation. 8. Motor or generator, according to claim 7, characterized in that the stator comprises one or more printed circuit board segments non-uniformly distributed over the axis of rotation. 9. Motor or generator, according to claim 1, characterized in that the stator comprises conductive traces arranged in at least one dielectric layer to generate the second magnetic flux when energized with current. 10. Motor or generator, according to claim 9, characterized in that the stator is configured so that, at any given time when the conductive traces are energized with current, one or more locations of maximum density of the second magnetic flux they are unevenly distributed over the axis of rotation. 11. Motor or generator, according to claim 10, characterized in that the conductive traces are arranged in the at least one dielectric layer and coupled to a power source to generate three phases of the second magnetic flux that correspond to three phases of emission of current by the power source. 12. Motor or generator, according to claim 10, characterized in that the stator comprises one or more printed circuit board segments non-uniformly distributed over the axis of rotation. 13. Motor or generator according to claim 1, characterized in that at least one of the rotor or stator is configured so that, as the rotor rotates through a range of angles with respect to the stator, the a constant speed, a periodicity of torque produced by virtue of the interaction of the first magnetic flux and the second magnetic flux is irregular. 14. Method, characterized in that it comprises: arranging one or more windings producing magnetic flux of a stator non-uniformly about an axis of rotation of a rotor of a motor or axial flux generator. 15. Method according to claim 14, characterized in that arranging the one or more magnetic flux producing windings comprises: arranging one or more printed circuit board segments including the windings non-uniformly about the axis of rotation. 16. Method according to claim 15, characterized in that the rotor comprises magnets arranged non-uniformly on the axis of rotation. 17. Method according to claim 15, characterized in that arranging the one or more printed circuit board segments further comprises: arranging the one or more printed circuit board segments so that at any given time when the windings are energized with current, one or more locations of maximum density of the second magnetic flux are unevenly distributed about the axis of rotation. 18. Method according to claim 14, characterized in that arranging the one or more magnetic flux producing windings comprises: arranging the one or more magnetic flux producing windings so that, as the rotor it rotates through a range of angles with respect to the stator at a constant speed, a periodicity of torque produced by virtue of the interaction of magnetic flux generated by the rotor and the stator is irregular. 19. Rotor for use in an engine or generator, characterized in that it comprises: a support structure; and one or more magnet segments which are supported by the support structure and which generate a first magnetic flux parallel to an axis of rotation about which the support structure rotates when mounted with a stator which generates a second magnetic flux parallel to the axis of rotation. rotation, wherein the one or more magnet segments are configured and arranged to generate a magnetic flux profile that is non-uniformly distributed about the axis of rotation. 20. The rotor of claim 19, wherein the one or more magnet segments include at least a first magnet segment and a second magnet segment spaced apart from the first magnet segment, the first magnet segment. magnet including a greater number of adjacent magnets than the second magnet segment.