阅读说明：本技术 用于轴向磁通机器中的磁体-定子间隙的控制的预弯曲转子 (Pre-bent rotor for control of magnet-stator gap in axial flux machines ) 是由 乔治·哈德·米列海姆 于 2018-05-25 设计创作，主要内容包括：一种用于轴向磁通马达或发电机的组件包括转子板和磁体,磁体具有与磁体的磁化方向正交的表面。转子板被调适成接合围绕旋转轴旋转的转子轴件,并且磁体附接至转子板。转子板和磁体被配置成且被布置使得,如果转子板和磁体与所有其他磁场生成部件分离,则在表面上截取第一点且与旋转轴垂直的第一平面和在表面上截取第二点且与旋转轴垂直的第二平面之间的距离基本上大于零。(an assembly for an axial flux motor or generator includes a rotor plate and a magnet having a surface orthogonal to a magnetization direction of the magnet, the rotor plate adapted to engage a rotor shaft that rotates about an axis of rotation, and the magnet attached to the rotor plate, the rotor plate and the magnet configured and arranged such that, if the rotor plate and the magnet are separated from all other magnetic field generating components, a distance between a plane that intersects the point on the surface and is perpendicular to the axis of rotation and a second plane that intersects the second point on the surface and is perpendicular to the axis of rotation is substantially greater than zero.)

1, an assembly for an axial flux motor or generator, comprising:

an th rotor plate adapted to engage a rotor shaft rotating about a rotation axis, and

an th magnet attached to the th rotor plate, the th magnet having a th surface orthogonal to a magnetization direction of the th magnet;

wherein the th rotor plate and the th magnet are configured and arranged such that, if the th rotor plate and the th magnet are separated from all other magnetic field generating components, a distance between an th plane that intersects the th point on the th surface and is perpendicular to the rotation axis and a second plane that intersects the second point on the th surface and is perpendicular to the rotation axis is substantially greater than zero.

2. The assembly of claim 1, wherein said th rotor plate has an annular shape with an opening at its center adapted to receive said rotor shaft.

3. The assembly of claim 1 or 2, wherein the portion of the rotor plate to which the th magnet is attached has the shape of a right circular conical frustum.

4. The assembly of any of claims 1-3, wherein the th magnet comprises a ring magnet having alternating poles.

5. The assembly of of claims 1-3, wherein the magnet is of a plurality of individual magnets disposed on the rotor plate at various angular positions about the axis of rotation.

6. The assembly of claim 5, wherein:

the th rotor plate is made of th material, and

separating and positioning the plurality of individual magnets using a second material different from the th material.

7. The assembly of any of claims 1-6, wherein:

the second point is a greater distance from the center of the magnet than the th point,

the th and second points contact the second surface of the th rotor plate at and second locations, respectively, and

the th rotor plate and the th magnet are further configured and arranged such that, if the th rotor plate and the th magnet are separated from all other magnetic field generating components, a ray extending away from and perpendicular to the second surface at the second location intercepts the th plane.

8. The assembly of claim 7 wherein the rotor plate and the magnet are further configured and arranged such that if the rotor plate and the magnet are separated from all other magnetic field generating components, the angle between the ray and the plane is substantially less than 90 degrees.

9. The assembly of any of claims 1-8, further comprising:

the rotor shaft, wherein the th rotor plate is engaged with the rotor shaft;

a second rotor plate engaged with the rotor shaft; and

a second magnet attached to the second rotor plate such that a th magnetic flux is generated within a gap between the th magnet and the second magnet.

10. The assembly of claim 9, wherein:

the second point is a greater distance from the center of the magnet than the point;

the th and second points contact the second surface of the th rotor plate at and second locations, respectively;

the th rotor plate and the second rotor plate being positioned such that the second plane is on the th side of the th plane, and

the th rotor plate and the th magnet are further configured and arranged such that, if the th rotor plate and the th magnet are separated from all other magnetic field generating components:

a ray extending away from and normal to the second surface at the second location would intercept the th plane, and

the second plane would remain on the side of the th plane.

11. The assembly of claim 9, wherein the th rotor plate and the second rotor plate are positioned such that the th magnetic flux causes a distance between the th plane and the second plane to be substantially equal to zero.

12. The assembly of any of claims 9-11, further comprising:

a stator disposed within the gap, wherein the stator is configured to selectively generate a second magnetic flux that interacts with the th magnetic flux to cause the rotor shaft, the th rotor plate, and the th magnet to rotate.

13. The assembly of claim 12, further comprising:

a housing at least partially enclosing the th rotor plate, the th magnet, the stator, the second rotor plate, the second magnet, and the portion of the rotor shaft, wherein:

the th rotor plate, the th magnet, the second rotor plate, the second magnet, and the rotor shaft are movable relative to the housing, and

the stator is fixed relative to the housing.

14. The assembly of claim 13, further comprising:

at least bearings disposed between the housing and the rotor shaft to allow relative movement between the housing and the rotor shaft.

15. The assembly of any of claims 9-14, wherein:

the th rotor plate, the th magnet, the second rotor plate, and the second magnet are configured and arranged such that a ratio of a distance between the th plane and the second plane to a distance between the th point and the second point is a th value, and

the th rotor plate and the th magnet are further configured and arranged such that, if the th rotor plate and the th magnet are separated from all other magnetic field generating means, a ratio of a distance between the th plane and the second plane to a distance between the th point and the second point is a second value that is at least twice the th value.

16. The assembly of any of claims 1-15, wherein:

the th magnet has an inner edge disposed at the th point;

the th magnet has an outer edge opposite the inner edge and disposed at the second point, and

the th rotor plate and the th magnet are further configured and arranged such that a ratio of a distance between the th plane and the second plane to a distance between the th point and the second point is greater than 0.002 if the th rotor plate and the th magnet are separated from all other magnetic field generating members.

17, a method for forming an assembly for an axial flux motor or generator, comprising:

attaching an th magnet to a th rotor plate, the 0 th magnet having a th surface orthogonal to a magnetization direction of the 1 th magnet, and wherein the th rotor plate is adapted to engage a rotor shaft that rotates about an axis of rotation and is configured such that, after the th magnet is attached to the th rotor plate, a distance between a th plane that intersects an th point on the th surface and is perpendicular to the axis of rotation and a second plane that intersects a second point on the th surface and is perpendicular to the axis of rotation is substantially greater than zero.

18. The method of claim 17, wherein said th rotor plate has an annular shape with an opening at its center, said opening adapted to receive said rotor shaft.

19. The method of claim 17 or 18 wherein the portion of the rotor plate to which the th magnet is attached has the shape of a right circular conical frustum.

20. The method of of any of claims 17 to 19, wherein the th magnet comprises a ring magnet with alternating poles.

21. The method of of any of claims 17-19, wherein the th magnet is of a plurality of individual magnets disposed on the th rotor plate at various angular positions about the axis of rotation.

22. The method of any of claims 17-21, wherein:

the second point is a greater distance from the center of the magnet than the point;

the th and second points contact the second surface of the th rotor plate at th and second positions, respectively, and

rays extending away from and perpendicular to the second surface at the second location intercept the plane after the th magnet is attached to the th rotor plate.

23. The method of claim 22, wherein,

after the th magnet is attached to the th rotor plate, the angle between the ray and the th plane is substantially less than 90 degrees.

24. The method of any of claims 17-23, further comprising:

engaging the th rotor plate with the rotor shaft, and

engaging a second rotor plate with the rotor shaft, wherein a second magnet is attached to the second rotor plate and generates a th magnetic flux within a gap between the th magnet and the second magnet.

25. The method of claim 24, wherein,

the second point is a greater distance from the center of the rotor plate than the th point;

the th and second points contact the second surface of the th rotor plate at and second locations, respectively;

a ray extending away from and perpendicular to the second surface at the second location intercepts the th plane and the second plane is on the th side of the th plane before joining the second rotor plate to the rotor shaft, and

the second plane is on the side of the th plane after the second rotor plate is joined to the rotor shaft.

26. The method of claim 24, wherein the th and second rotor plates are engaged with the rotor shaft such that the th magnetic flux causes a distance between the th and second planes to be substantially equal to zero.

27. The method of of any of claims 24-26, wherein engaging the second rotor plate with the rotor shaft further comprises:

engaging the second rotor plate with the rotor shaft such that a stator is disposed within the gap, wherein the stator is configured to selectively generate a second magnetic flux that interacts with the th magnetic flux to cause the rotor shaft, the th rotor plate, and the th magnet to rotate.

28. The method of any of claims 24-27, wherein:

the ratio of the distance between the th plane and the second plane to the distance between the th point and the second point is a th value prior to engaging the second rotor plate with the rotor shaft, and

after engaging the second rotor plate with the rotor shaft, a ratio of a distance between the th plane and the second plane to a distance between the th point and the second point is a second value, wherein the th value is at least twice the second value.

29. The method of any of claims 24-28, wherein:

the th magnet has an inner edge disposed at the th point;

the th magnet has an outer edge opposite the inner edge and disposed at the second point, and

a ratio of a distance between the th plane and the second plane to a distance between the th point and the second point after the th magnet is attached to the th rotor plate and before the second rotor plate is engaged with the rotor shaft is greater than 0.002.

30. The method of of any of claims 17-28, wherein, after the magnet is attached to the rotor plate:

the th magnet has an inner edge disposed at the th point;

the th magnet has an outer edge opposite the inner edge and disposed at the second point, and

a ratio of a distance between the th plane and the second plane to a distance between the th point and the second point is greater than 0.002.

Background

Axial flux motors and generators typically employ a stator in a gap formed between pairs of opposing magnets that generate magnetic flux and a rotor that supports the magnets and allows the magnets to rotate in unison relative to the stator . an example of such an axial flux motor or generator 100 is shown in fig. 1 and 2. as shown, the motor or generator 100 includes pairs of annular magnets 102a, 102b on either side of the stator 104. the magnets 102a, 102b are supported by respective rotor plates 106a, 106b that are fixedly attached to the shaft 108. the magnets 102a, 102b, the stator 104, and the rotor plates 106a, 106b are all contained within the housing 110. the periphery of the stator 104 is fixed between the two portions 110a, 110b of the housing 110, so the stator 104 remains stationary relative to the housing 110.

Magnets 102a, 102b, rotor plates 106a, 106b, and shaft 108 together form a "rotor assembly" that is rotatable relative to stator 104 and housing 110. as shown in fig. 2, a slight gap 112a between the top of rotor plate 106a and the inner surface of upper housing half 110a and a slight gap 112b between the bottom of rotor plate 106 and the inner surface of lower housing half 110b allow the rotor assembly to rotate relative to housing 110. similarly, a slight gap 114a between the bottom of magnet 102a and the top of stator 104 (and between the exposed bottom of rotor plate 106a and the top of stator 104) and a slight gap 114b between the top of magnet 102b and the bottom of stator 104 (and between the exposed top of rotor plate 106b and the bottom of stator 104) allow rotation relative to stator 104. bearing 116a, 116b between shaft 108 and housing 110 allow the rotor assembly to freely rotate relative to stator 104 and housing 110 in a controlled manner.

Disclosure of Invention

In embodiments, a assembly for an axial flux motor or generator includes a rotor plate and a magnet having a surface orthogonal to a magnetization direction of the magnet, the rotor plate adapted to engage a rotor shaft that rotates about an axis of rotation, and the magnet attached to the rotor plate, the rotor plate and the magnet configured and arranged such that, if the rotor plate and the magnet are separated from all other magnetic field generating components, a distance between a plane that intercepts a th point on the surface and is perpendicular to the axis of rotation and a second plane that intercepts a second point on the surface and is perpendicular to the axis of rotation is substantially greater than zero.

In embodiments, methods for forming an assembly for an axial flux motor or generator include attaching magnets to a rotor plate, the magnets having surfaces orthogonal to a magnetization direction of a th magnet the rotor plate is adapted to engage a rotor shaft that rotates about an axis of rotation and is configured such that, after the magnets are attached to the rotor plate, a distance between a th plane that intercepts a th point on the surface and is perpendicular to the axis of rotation and a second plane that intercepts a second point on the surface and is perpendicular to the axis of rotation is substantially greater than zero.

Drawings

FIG. 1 shows a cut-away perspective view of an axial flux motor or generator;

FIG. 2 illustrates a cross-sectional side view of the axial flux motor or generator illustrated in FIG. 1;

FIG. 3 shows a cross-sectional side view of a portion of an axial flux motor or generator similar to that shown in FIGS. 1 and 2 with exaggerated clearances and rotor deflection;

FIG. 4 illustrates a cross-sectional side view of an axial flux motor or generator employing an example of a pre-bent rotor element as disclosed herein;

FIG. 5A shows a perspective view of a system including a controller in addition to the components of the motor or generator shown in FIG. 4;

FIG. 5B shows an expanded view of the system shown in FIG. 5A;

FIG. 6 shows a cross-sectional side view of an example of a rotor plate having a tapered region to allow for the formation of a pre-curved rotor element as disclosed herein;

FIG. 7 illustrates a side cross-sectional view of an example of a pre-curved rotor element as disclosed herein;

FIG. 8 shows a top view of an example of a rotor plate such as that shown in FIG. 6;

FIG. 9 illustrates a top view of a ring magnet that may be employed in embodiments ;

FIG. 10 shows a cross-sectional side view of a pre-bent rotor element illustrating how the rotor element may be bent into a desired configuration when the rotor element is incorporated into a rotor assembly.

FIG. 11 shows a cross-sectional side view of an example of a motor or generator assembly including pre-bent rotor elements such as those shown in FIG. 7, including excessive gaps between the various magnets;

FIG. 12 shows a side cross-sectional view of an example of a motor or generator including a pre-curved rotor element as disclosed herein;

FIG. 13 is a photograph showing the top of a pre-curved rotor element configured as described herein; and

fig. 14 is a photograph of the side of the pre-bent rotor element shown in fig. 13.

Detailed Description

Axial flux motors and generators described by several patents, including U.S. patent No. 7,109,625 ("the' 625 patent"), the entire contents of which are incorporated herein by reference, feature a substantially planar printed circuit board stator assembly disposed between magnets alternately magnetized in north-south poles, which are secured to a shaft by a "back iron" for connection to a mechanical load (or source of the generator). such back iron provides a flux return path and may correspond, for example, to rotor plates 106a, 106b shown in fig. 1 and 2. the flux density in the gap is largely dependent on the spacing between the two magnets.

At , machined faces (e.g., back iron) on the rotor plate may be used to achieve a pre-bent state such that when assembled, the force of the magnets bends the rotor plate to a position that creates a desired gap in embodiments, a rounded conical taper may be machined on the surface of a previously flat rotor plate, creating a curved surface that is bent to a substantially parallel or other desired state when assembled into a motor or generator and acted upon by magnetic force.

As mentioned above, the amount of torque that can be produced for a given current density in the stator is proportional to the magnetic field in the gap the size of the gap can have a large effect on the magnetic field strength such that it is generally desirable to reduce the size of the gap as much as possible, this creates problems, i.e. the same magnetic field increase will exert a greater force on the rotor plates as the gap size is reduced, causing the rotor plates to bend FIG. 3 shows a cross-sectional side view of a portion of a simplified axial flux motor or generator similar to that shown in FIGS. 1 and 2, but with the size of the gap and the amount of deflection exaggerated to illustrate the nature of the problem.

The conventional approach, i.e., increasing the gap size, results in a reduction in magnetic field strength for a given magnet size, the second conventional approach, i.e., increasing the rotor bending strength, requires an increase in the thickness of the rotor, which increases the overall mass of the machine and reduces the desired slim form factor, it may also require the use of more complex manufacturing processes, thereby increasing overall cost, in the motor or generator 100 shown in FIG. 2, for example, every of the rotor plates 106a, 106b are provided with an edge 115 and an area 118 of increased thickness near the center of the rotor plates 106a, 106 b.

As shown in FIGS. 1 and 2, in axial flux machines, bearings 116a, 116b are used to support the rotor plates 106a, 106b and attached magnets 102a, 102 b. these bearings 116a, 116b are supported by respective housing portions 110a, 110b that are gathered at , clamping the stator 104 around the stator 104 perimeter the rotor-stator alignment is determined by the alignment of the shaft 108 with the bearings 116a, 116 b. the bearings 116a, 116b have a quantitative radial deflection that increases as the bearings wear.

FIG. 4 is a side cross-sectional view of an example embodiment of a motor or generator 400 including pre-bent rotor elements according to the present disclosure, it can be seen that motor or generator 400 has several components in common with motor or generator 100 shown in FIGS. 1 and 2, but also several significant differences, differences between the two designs relate to the configuration of hub 422 in motor or generator 400, as shown, hub 422 may be used to join rotor plates 406a, 406b and shaft 408 at , with pins 424a, 424b used to index rotor plates 406a, 406b to hub 422 and to each other, and pins 426 used to index hub 422 to shaft 408. in addition, pre-bending of rotor elements (as discussed in more detail below) prior to assembly allows rotor plates 406a, 406b in motor or generator 400 to be smaller and/or less complex than rotor plates 106a, 106b in motor or generator 100, thereby allowing motor/generator 400 to achieve a slimmer form factor, and/or less difficult and/or inexpensive to manufacture and/or less expensive to implement, e.g., the center plate area of rotor plates 106a, 406b, shown in FIG. 4, the center area of rotor plates 406a, 406b, not including the center plate, 406a, and the area of rotor plates, 406b, shown in FIG. 4.

The assembly including the pre-bent rotor element as described herein may be used in any known or future developed motor or generator, including the axial flux motor/generator described in the' 625 patent, as well as the motors and generators described in U.S. patent No. 9,673,684 and U.S. patent No. 9,800,109, the entire contents of each of which are incorporated herein by reference.

Fig. 5A illustrates an example of a system 500 that includes a controller 532 in addition to a motor or generator assembly 420 similar to that shown in fig. 4. An expanded view of the components of the motor or generator assembly 420 and their manner of assembly is shown in FIG. 5B. As shown, the stator 104 may be disposed in a gap between two pre-bent rotor elements 534a, 534b, each rotor element 534a, 534b including a magnet 102a, 102b attached to a respective rotor plate 406a, 406 b. The pattern of the magnetic poles in the magnets 102a, 102B is also evident in the expanded view of fig. 5B. As discussed above, screws or other fasteners 528 may be used to secure the rotor elements 534a, 534b to the hub 422, and pins 424a, 424b, and 426 may be used to index the rotor elements and shaft members.

In the embodiment shown, electrical connections 530 are made at the outer radius of the stator 104 and the stator is mounted to the frame or housing at the outer periphery Another useful configurations, an "out-runner" configuration, includes mounting the stator 104 at the inner radius, making electrical connections 530 at the inner radius, and replacing the shaft 408 with an annular ring (not shown) separating the rotor halves the system can also be configured with only magnets 102a or 102b, or placing multiple stators between successive magnet assemblies the wires 530 can also convey information about the position of the rotor based on readings of Hall effect or similar sensors (not shown) mounted on the stators.

The system 500 in fig. 5A and 5B may function as a motor or a generator depending on the operation of the controller 532 and components connected to the shaft 408 as a motor system, the controller 532 may operate switches such that the current in the stator 104 generates torque around the shaft 408 due to magnetic flux originating in the gap of the magnets 102a, 102B connected to the shaft 408. depending on the design of the controller 532, the magnetic flux in the gap and/or the position of the rotor may be measured or estimated to operate the switches to achieve torque output at the shaft 408. as a generator system, a mechanical rotary power source connected to the shaft 408 generates voltage waveforms at the terminals of the stator, these voltages may be applied directly to a load, or may also be rectified with a three-phase (or multi-phase) rectifier in the controller 532.

Fig. 6 and 7 illustrate an example method for forming a pre-bent rotor element 534b including a rotor plate 406b and magnets 102b similar techniques may be employed to form a pre-bent rotor element 534a located on the other side of the gap in which the stator is disposed (see, e.g., fig. 10-12.) examples of techniques for aligning magnets 102a, 102b with rotor plates 406a, 406b during assembly are described, for example, in U.S. patent No. 9,673,688, which is incorporated herein by reference in its entirety.

As seen in FIG. 6, the rotor plate 406b may be formed to include a tapered surface region 604 relative to a plane perpendicular to the axis of rotation 602 of the rotor shaft and a central region 606 having a generally flat surface parallel to such planes, a top view of the rotor plate 406b is shown in FIG. 8 including the tapered surface region 604 and the central region 606. the rotor plate 406b may additionally include holes 802 for receiving the pins 424a, 424b, holes 804 for receiving the screws 528, and holes 806 for receiving the shaft 408, all within the central region 606. the tapered surface region 604 may take any of a variety of forms and the invention is not limited to any particular configuration or type of taper.

As shown in FIG. 7, the magnet 102b may be attached to the upper surface of the rotor plate 406b such that it contacts at least portions of the tapered surface region 604 in the illustrated embodiment, the magnet 102b has an annular shape that covers substantially all of the tapered (e.g., conical) region 604. A top view of the annular magnet 102b is shown in FIG. 9. As shown, a circular aperture 902 in the magnet 102b has a radius R1 measured from a central point 904, and a circular outer perimeter 906 of the magnet 102b has a radius R2. attaching the annular magnet 102b to the tapered region 604 as shown in FIG. 7 will bend the magnet 102b and at least partially conform to the shape of the circular tapered region 604. this bending of the magnet will force and bend the body of the rotor plate 406 b.

As shown in fig. 7, the degree of taper of the surface region 604 may be measured by identifying two points 702, 704 on the surface of the rotor plate 406b that contact the lower surface 720 of the magnet, and determining a distance D1 between two planes 706, 708 that are perpendicular to the axis of rotation 602 and that intercept the and second points 702, 704, respectively, in the example shown, the lower surface of the magnet that contacts the conically tapered region 604 is orthogonal to the magnetization direction of the magnet 102b in embodiments, two magnet contact points 702, 704 (at the inner radius R1 and the outer radius R6 of the magnet, or elsewhere) may be found, the distance D1 may be, for example, greater than 0.003 inches, or greater than 0.01 inches, or even greater than 0.02 inches in this context, the term "substantially" is intended to exclude slight variations within allowable tolerances due to machining and/or material defects in embodiments, the distance D1 may be, for example, greater than 0.003 inches, or greater than 0.01 inches, or even greater than 0.5392 inches in embodiments, the distance D865 may be found, the ratio between the two magnet contact points 702, 704 may be greater than the distance R460, or , or even greater than the ratio of the distance R9 to the distance R9, the distance R460, f between the radius R460, or the radius R3, in other embodiments.

Also as shown in fig. 7, in embodiments, at least points 710 may be found on the surface of the rotor plate 106b that contacts the magnet 102b, for which at least points 710 a ray 712 extending away from and perpendicular to the surface and a plane perpendicular to the axis of rotation 602 form an angle α 1, the angle α 1 being substantially less than 90 degrees, in implementations, the angle α 1 may be, for example, less than 89.9 degrees, less than 89.7 degrees, or even less than 89.5 degrees, the points 710 may be positioned at the inner diameter R1 of the magnet 102b, at the outer diameter R2 of the magnet 102b, or at some point between the two radii.

Additionally or alternatively, and as also shown in fig. 7, the degree of taper of the magnet 102b when attached to the rotor plate 406b may be measured by identifying the surface of the magnet 102b that is orthogonal to the magnetization direction of the magnet 102b, e.g., two points 714, 716 on the upper surface 718 of the magnet 102b shown in fig. 7 and determining a distance D2 between two planes 726, 728 that are perpendicular to the axis of rotation 602 and that respectively intercept the point 714 and the second point 716 in the example shown, the lower surface of the magnet that contacts the conically tapered region 604 is also orthogonal to the magnetization direction of the magnet 102b, in embodiments, two magnet surface points 714, 716 may be found (at the inner radius R1 and the outer radius R2 of the magnet, or elsewhere), the distance D2 is substantially greater than zero for the two magnet surface points 714, 716, in embodiments, the distance D2 may be, e.g., greater than 0.002, or greater than 0.005 inches, or even greater than 0.01 inches, in alternative embodiments, the ratio of the distance D2 may be found to the distance D9, or even greater than the distance D9/26 in embodiments, or even greater than the distance between the radius R9, or the radius R8, or the distance between the magnet radius R8, or the alternative embodiments.

As also shown in fig. 7, in embodiments, at least points 722 may be found on a surface of the magnet 102b that is orthogonal to the magnetization direction of the magnet 102b, such as the upper surface 718, for which at least points 722 a ray 724 extending away from and perpendicular to the magnet surface and a plane perpendicular to the axis of rotation 602 form an angle α 2, the angle α 2 being substantially less than 90 degrees, in implementations, the angle α 2 may be, for example, less than 89.9 degrees, less than 89.7 degrees, or even less than 89.5 degrees, the points 722 may be positioned at the inner diameter R1 of the magnet 102b, the outer diameter R2 of the magnet 102b, or some point between the two radii.

As shown in fig. 10, when the two rotor elements 534a, 534B are attached to the shaft 408 and the hub 422 (not shown in fig. 10), the magnetic flux of the magnets 102a, 102B creates an attractive force in the gap 1002 between the magnets that bends the rotor elements 534a, 534B such that the ends of the rotor elements 534a, 534B move towards each other the dashed lines in fig. 10 show how the rotor elements 534a, 534B can be shaped after assembly of the rotor elements 534a, 534B into a motor or generator such as shown in fig. 4, 5A and 5B, in some embodiments the rotor elements 534a, 534B are pre-bent prior to assembly such that the surfaces of the two magnets 102a, 102B facing each other are substantially parallel in the assembled motor or generator 400, thus making the width of the gap 1002 substantially uniform throughout.

As shown in FIG. 10, the amount of bending experienced by the rotor element 534b after assembly may be measured by identifying a point 1004 located at the outer diameter R2 of the magnet 102b and determining a distance D3 that the point moves in a direction coincident with the axis of rotation 602 after assembly.A distance D3 may be measured, for example, by identifying a plane that intercepts 1004 and is perpendicular to the axis of rotation 602 and determining the distance that such planes move relative to another plane that intercepts or is near the center of the rotor element 534b and is also perpendicular to the axis of rotation 602. in embodiments , distance D3 is greater than 0.001 inches, or greater than 0.005 inches, or even greater than 0.01 inches additionally or alternatively, in embodiments , the ratio of distance D3 to the average width G of the gap 1002 is greater than 0.01, or greater than 0.05, or even greater than 0.1. additionally or alternatively, the ratio of the distance D3 to the average width G of the surface of the stator 104 (not shown in FIG. 10) and the average gap G of the magnet 102b may be greater than 0.5, the average magnet spacing ratio of magnet 735 to the distance of the stator element 534b, or even greater than 0.5/or even more than the average magnet spacing distance of the stator element 534b in embodiments.

Referring to fig. 7 in conjunction with fig. 10, it should be understood that in embodiments, rotor elements 534a, 534b may be configured and arranged such that, for each rotor element, when rotor element 534a, 534b is attached to shaft 408 and deflected as shown in fig. 10, or more of the following values may reduce fifty percent or more than fifty percent (1) the distance D1 between plane 706 and plane 708, (2) the ratio of the distance between distance D1 and point 702 704 and/or the ratio of the distance D1 and the difference between the inner diameter R1 and the outer diameter R2 of the magnet, (3) the distance D2 between plane 726 and plane 728, and (4) the ratio of distance D2 and the distance between point 714 and point 716 and/or the ratio of the distance D2 and the difference between the inner diameter R1 and the outer diameter R2 of the magnet.

Fig. 11 shows a motor or generator assembly 420 with exaggerated gaps between the magnets 102a, 102b, wherein the rotor elements 534a, 534b are pre-bent prior to assembly such that the surfaces 1102, 1104 of the two magnets 102a, 102b facing each other are substantially parallel after assembly.

Fig. 12 shows a motor or generator assembly 420 in which pre-bent rotor plates 406a, 406b are employed, each having a more uniform width throughout. In such implementations, the tapered surfaces to which the magnets 102a, 102b are attached may each have a shape similar to the examples shown in fig. 6 and 7, but the thickness of the rotor plates 406a, 406b may be substantially constant in the radial direction. In other embodiments, pre-bending may be employed when the thickness of the rotor plates 406a, 406b is otherwise varied for various reasons, such as to optimize the reluctance of the rotor plates 406a, 406b to maximize the performance of the motor or generator 400.

This design is common in axial flux machines and suffers from the same deflection issues, a circular rotor plate with a conical cone may be used, or each magnet may be placed in its own pocket (pocket), each of these magnets tapering individually so that when assembled into a motor or generator, the gap size does not decrease at the outer diameter.

FIGS. 13 and 14 are photographs of rotor elements 534 assembled and configured as described herein, hi the example shown, the amount of taper (i.e., value D1 described in connection with FIG. 7) is very slight, with only 0.005 inches of deviation from a flat face at the outer diameter, which is imperceptible in the image. in this case, a computer model incorporating Finite Element Analysis (FEA) is used to determine the strength of the magnetic attraction force and resulting bending of the rotor elements 435. the resulting deflection is calculated to be 0.002 inches. an additional 0.003 inches of cone is added to allow for some radial deflection and misalignment of the of the bearings 116a, 116 b. a machined fixture for this application is used to bend the rotor into a 0.005 inch deflection state in the opposite direction that the rotor will experience in the motor or generator 400. when in this state, the magnet bearing surface of the rotor plate 406 is machined to be flat so that when disassembled from the fixture, it will have the desired conical shape of the annular magnet 102. the magnet 406 is then deflected to a much closer to the magnet 102 as the magnet 406 is assembled and the magnet 406 is not induced by much lower modulus of elasticity than when the magnet 406 is used.

As in the above example, the force acting on the rotor plate 406 due to the magnetic field and the resulting deflection profile can be accurately determined using computer-based methods such as FEA. typically, the simple geometry of a constant thickness rotor results in a linear deflection curve that varies as a function of radius in the magnet mounting area, making the desired taper a linear function of radius as seen in the examples discussed above. while materials are removed, this taper does reduce the bending strength of the rotor plate 406. while it will be possible to use iterative methods to account for the varying nature, the taper can be made small enough, which is not necessary.

The machining fixture described above provides a repeatable, predictable method of machining a cone onto a rotor by using a simple flat-face machining machine tool. Other methods may be used to manufacture future tapered rotors, particularly when a non-linear taper is desired. Modern tools allow for the development of precise designs and machining complex geometries that can be used as part of the optimization process of an axial flux machine.

Tapered rotor elements of the type described herein have been used to run motors and have proven to be a repeatable, effective method of controlling the size of the magnet-stator gap in an axial flux machine. Measurements indicate that the taper in the produced rotor element, such as shown in fig. 13 and 14, is accurate, and the assembly has confirmed that the magnet 102 is aligned with the taper when attached to the rotor plate 406.

Having thus described several aspects of at least embodiments of the present invention, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art, which alterations, modifications, and improvements are intended to be part of the portion of this disclosure and are intended to be within the spirit and scope of the invention.

Various aspects of the present invention may be used alone, in combination, or in a variety of arrangements not specifically discussed in the embodiments described in the foregoing and is therefore not limited in this application to the details and arrangement of components set forth in the foregoing description or illustrated in the drawings.

Thus, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing acts simultaneously, even though the acts are illustrated as sequential acts in the illustrative embodiments.

Use of ordinal terms such as "", "second", "third", etc., in the claims to modify a claim element does not by itself connote any priority, order, or sequence of claim elements over another claim elements or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish claimed elements having a certain name from another elements having the same name (except for use of the ordinal term) to distinguish the claim elements.

Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," or "having," "containing," "involving," and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.