Magnetic gear system, method, and apparatus

Abstract

Aspects of the disclosure relate to a cycloidal magnetic gear. The cycloidal magnetic gear includes an outer rotor. A plurality of magnetic pole pairs are disposed on an inner circumference of the outer rotor. A first inner rotor, a second inner rotor, and a third inner rotor are disposed within the outer rotor. The first inner rotor, the second inner rotor, and the third inner rotor include magnetic pole pairs disposed on an outer circumference. The first inner rotor and the third inner rotor have approximately half the thickness of the second inner rotor. The first inner rotor, the second inner rotor, and the third inner rotor balance a moment acting on a drive shaft.

Description

[Technical field]

[0001] Statement of Federally Funded Research This invention was made with Government support under Grant No. 28-517790-00001 awarded by the National Aeronautics and Space Administration (NASA). The Government has certain rights in this invention.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS This patent application claims priority to U.S. Provisional Patent Application No. 63 / 141,130, filed January 25, 2021, U.S. Provisional Patent Application No. 63 / 185,090, filed May 6, 2021, and U.S. Provisional Patent Application No. 63 / 188,009, filed May 13, 2021, the disclosures of which are incorporated by reference in their entireties.

[0003] The present disclosure relates generally to magnetic gears, and more particularly, but not by way of limitation, to magnetic gear systems, methods, and apparatus. [Background technology]

[0004] This section provides background information to facilitate a better understanding of the various aspects of the disclosure. It should be understood that statements in this section of the specification are to be read in this light, and not as admissions of prior art.

[0005] Magnetic gears perform the same tasks as their mechanical counterparts, but they do so through modulated interactions between the magnetic fluxes generated by magnets, rather than through mechanical interactions between the gear teeth. In the case of a cycloidal gear configuration, if the center of mass of the inner rotor is not aligned with the center of the axis of the stationary outer rotor, undesirable mechanical vibrations can result as a result of the orbital motion of the inner rotor. Multiple rotor segments can be used to balance the gearbox. However, the use of multiple rotor segments results in off-axis moments due to magnetic interactions between the inner and outer rotors if the magnetic moments are not balanced. Summary of the Invention

[0006] This Summary is provided to introduce a selection of concepts that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

[0007] An aspect of the disclosure relates to a cycloidal magnetic gear having an outer rotor, a first plurality of magnetic pole pairs disposed on an inner circumference of the outer rotor, a first inner rotor disposed within the outer rotor and having a second plurality of magnetic pole pairs disposed on an outer circumference, a second inner rotor disposed within the outer rotor and having a third plurality of magnetic pole pairs disposed on an outer circumference, and a third inner rotor disposed within the outer rotor and having a fourth plurality of magnetic pole pairs disposed on an outer circumference. The first inner rotor and the third inner rotor have approximately half the thickness of the second inner rotor. The first inner rotor, the second inner rotor, and the third inner rotor balance the moment acting on the drive shaft.

[0008] An aspect of the disclosure relates to a method of assembling a cycloidal magnetic gear, the method including coupling a first plurality of magnetic pole pairs, a second plurality of magnetic pole pairs, and a third plurality of magnetic poles to an inner circumference of an outer rotor; coupling the first inner rotor, the second inner rotor, and the third inner rotor to an input shaft; coupling a fourth plurality of magnetic pole pairs to the first inner rotor, a fifth plurality of magnetic pole pairs to the second inner rotor, and a sixth plurality of magnetic pole pairs to the third inner rotor; and disposing the first inner rotor, the second inner rotor, and the third inner rotor within the outer rotor such that the fourth plurality of magnetic pole pairs interact with the first plurality of magnetic pole pairs, the fifth plurality of magnetic pole pairs interact with the second plurality of magnetic pole pairs, and the sixth plurality of magnetic pole pairs interact with the third plurality of magnetic pole pairs.

[0009] An aspect of the disclosure relates to a cycloidal magnetic gear having an outer rotor, a first plurality of teeth formed in the outer rotor, a first plurality of permanent magnets disposed between adjacent teeth of the outer rotor, a first inner rotor disposed in the outer rotor and having a second plurality of teeth formed on an outer periphery, the second plurality of permanent magnets disposed between adjacent teeth of the second plurality of teeth, a second inner rotor disposed in the outer rotor and having a third plurality of teeth formed on an outer periphery, the third plurality of permanent magnets disposed between adjacent teeth of the third plurality of teeth, and a third inner rotor disposed in the outer rotor and having a fourth plurality of teeth formed on an outer periphery, the fourth plurality of permanent magnets disposed between adjacent teeth of the fourth plurality of teeth. The first inner rotor and the third inner rotor have an axial length approximately half the thickness of the second inner rotor. The first inner rotor, the second inner rotor, and the third inner rotor balance a moment acting on a drive shaft.

[0010] Aspects of the present disclosure relate to a cycloidal magnetic gear having an outer rotor, an inner rotor, a plurality of permanent magnets disposed around a periphery of at least one of the outer rotor or the inner rotor, and a plurality of non-magnetic spacers positioned between individual magnets of the plurality of permanent magnets.

[0011] Aspects of the present disclosure relate to a cycloidal magnetic gear having an outer rotor, an inner rotor, a plurality of permanent magnets disposed around a periphery of at least one of the outer rotor or the inner rotor, and a keyway formed in at least one of the outer rotor or the inner rotor.

[0012] Aspects of the disclosure relate to a method of producing a multi-rotor cycloidal magnetic gear, the method including forming an outer rotor back core, forming an inner rotor back core, cutting the inner rotor along a plane perpendicular to a central axis of the inner rotor to produce a plurality of inner rotors, disposing a first plurality of permanent magnets on the outer rotor back core, and disposing a second plurality of permanent magnets on the inner rotor back core to form the inner rotors.

[0013] An aspect of the present disclosure relates to a cycloidal magnetic gear system having a first cycloidal magnetic gear having a first input shaft and a first output shaft, and a second cycloidal magnetic gear receiving an input from the first output shaft and including a second output shaft, the first output shaft being supported by a first bearing and a second bearing.

[0014] An aspect of the present disclosure relates to a cycloidal magnetic gear having a first rotor. The first rotor includes at least one of a plurality of magnetic pole pairs disposed on the first rotor, or a plurality of first rotor permanent magnets disposed on the first rotor and a plurality of first rotor ferromagnetic teeth formed on the first rotor, each tooth of the plurality of first rotor ferromagnetic teeth being disposed between successive magnets of the plurality of first rotor permanent magnets. The plurality of first rotor ferromagnetic teeth are consequently magnetized by the plurality of first rotor permanent magnets. The cycloidal magnetic gear further includes a second rotor, a plurality of permanent magnets disposed on the second rotor, and a plurality of ferromagnetic teeth formed on the second rotor, each tooth of the plurality of ferromagnetic teeth being disposed between successive magnets of the plurality of permanent magnets. The plurality of ferromagnetic teeth are consequently magnetized by the plurality of permanent magnets.

[0015] Aspects of the present disclosure relate to a cycloidal magnetic gear having a first rotor, a second rotor, a number of magnetic pole pairs disposed on the first rotor, and a number of ferromagnetic teeth formed on the second rotor, the second rotor interacting with the first rotor due to magnetic reluctance.

[0016] Aspects of the disclosure relate to a cycloidal magnetic gear having an outer rotor, an inner rotor disposed within the outer rotor, an air gap defined between the outer rotor and the inner rotor, and a flux shield disposed within the air gap between the outer rotor and the inner rotor, the flux shield extending in part around a circumference of the air gap.

[0017] Aspects of the disclosure relate to a concentric gear system having a first rotor. The first rotor has at least one of a plurality of permanent magnets, a plurality of magnetically permeable teeth, or a plurality of electromagnets. The concentric gear system further includes a second rotor. The second rotor has at least one of a plurality of permanent magnets, a plurality of magnetically permeable teeth, or a plurality of electromagnets. The concentric gear system includes a modulator disposed between the first rotor and the second rotor, the modulator having a plurality of magnetically permeable segments arranged to alternate with a plurality of non-magnetic segments. Each magnetically permeable segment of the plurality of magnetically permeable segments is disposed between consecutive non-magnetic segments of the plurality of non-magnetic segments. Each magnetically permeable segment of the plurality of magnetically permeable segments and each non-magnetic segment of the plurality of non-magnetic segments is formed by a protrusion extending outwardly from a first end and a recess extending inwardly from a second end.

[0018] Aspects of the disclosure relate to a concentric gear system having a first rotor. The first rotor includes at least one of a plurality of permanent magnets, a plurality of magnetically permeable teeth, or a plurality of electromagnets. The concentric gear system further includes a second rotor. The second rotor includes at least one of a plurality of permanent magnets, a plurality of magnetically permeable teeth, or a plurality of electromagnets. The concentric gear system further includes a modulator having a plurality of magnetically permeable modulator segments. Each modulator segment of the plurality of modulator segments maps an electromagnetic angle from a first plurality of magnetic pole pairs to a second plurality of magnetic pole pairs.

[0019] A more complete understanding of the subject matter of the present disclosure can be obtained by reference to the following detailed description when taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0020] [Figure 1] FIG. 2 is a cross-sectional view of a magnetocycloid gear according to an aspect of the present disclosure. [Diagram 2] 11A-11C are a series of diagrams illustrating orbital motion of the hypercycloidal rotor relative to rotation of the hypercycloidal rotor in accordance with aspects of the present disclosure. [Figure 3A]FIG. 1 is a cross-sectional view of a cycloidal magnetic gear utilizing a consequent pole placement configuration, according to an aspect of the present disclosure. [Figure 3B] FIG. 2 is a schematic diagram of an inner rotor of a cycloidal magnetic gear having keyways formed therein, according to aspects of the present disclosure. [Figure 3C] FIG. 2 is a schematic diagram of an outer rotor of a cycloidal magnetic gear having through holes formed therein, according to an aspect of the present disclosure. [Figure 3D] FIG. 1 is a schematic diagram of a cycloidal magnetic gear having a surface permanent magnet outer rotor and a consequent pole inner rotor according to an aspect of the present disclosure. [Figure 3E] FIG. 1 is a schematic diagram of a cycloidal magnetic gear utilizing an axially magnetized consequent pole placement configuration (top rotor-surface permanent magnet, bottom rotor-consequential) in accordance with an aspect of the present disclosure. [Figure 4] FIG. 1 is an exploded view of a cycloidal magnetic gear utilizing both radially and axially magnetized magnets, according to an aspect of the present disclosure. [Diagram 5] 1 is a flow diagram illustrating a process for assembling a cycloidal magnetic gear according to an aspect of the present disclosure. [Figure 6] FIG. 2 is a cross-sectional view of a magnetocycloid gear having a spacer according to an aspect of the present disclosure. [Figure 7] FIG. 2 is an exploded view of a cycloidal magnetic gear having a spacer according to an aspect of the present disclosure. [Figure 8] FIG. 1 is a perspective view of a cycloidal magnetic gear having a spacer according to an aspect of the present disclosure. [Figure 9] FIG. 13 is a detailed view of a cycloidal magnetic gear with a spacer showing keyways formed therein, according to aspects of the present disclosure. [Figure 10] FIG. 1 is a cross-sectional view of a two-stage cycloid magnetic gear. [Figure 11] FIG. 2 is a cross-sectional view of a two-stage cycloidal magnetic gear according to an embodiment of the present disclosure. [Figure 12A] FIG. 1 is a schematic diagram of a reluctance-type cycloidal magnetic gear according to an aspect of the present disclosure. [Figure 12B]FIG. 1 is a schematic diagram of a reluctance-type cycloidal magnetic gear utilizing an axial magnetization arrangement in accordance with aspects of the present disclosure. [Figure 13] FIG. 1 is a schematic diagram of a magnetocycloid gear having a keyway, according to an aspect of the present disclosure. [Figure 14] FIG. 2 is a schematic diagram of a cycloidal magnetic gear having a flux shield, according to an aspect of the present disclosure. [Figure 15] 4 is a schematic diagram illustrating force distribution on an inner rotor of a cycloidal magnetic gear at a particular instant in time, according to an aspect of the present disclosure. FIG. [Figure 16] FIG. 1 illustrates a perspective view of a flux shield with mass removed, according to an aspect of the present disclosure. [Figure 17] FIG. 13 is a perspective view of a flux shield with added mass according to an aspect of the present disclosure. [Figure 18A] FIG. 13 is a top perspective view of a flux shield with mass removed, according to aspects of the present disclosure. [Figure 18B] FIG. 2 is a cross-sectional view of a magnet gear having an input shaft. [Figure 18C] FIG. 2 is a cross-sectional view of a magnet gear having an input shaft with a flux shield according to an aspect of the present disclosure. [Figure 19] FIG. 2 is a cross-sectional view of a cycloidal magnetic gear having an offset flux shield according to an aspect of the present disclosure. [Figure 20] FIG. 13 is a perspective view of a flux shield engaged with an output pin disk according to an aspect of the present disclosure. [Figure 21] FIG. 1 is a perspective view of a flux shield having a bearing with a lip, according to an aspect of the present disclosure. [Figure 22] FIG. 1 is a perspective view of a system of multiple flux shields and pin disks according to an aspect of the present disclosure. [Figure 23] FIG. 1 illustrates a cross-sectional view of a concentric gear system having a gear modulator according to an aspect of the present disclosure. [Figure 24A] 1A-1C are cross-sectional views of concentric gears having various modulator segment shapes according to aspects of the present disclosure. [Figure 24B] 1A-1C are cross-sectional views of concentric gears having various modulator segment shapes according to aspects of the present disclosure. [Figure 24C] 1A-1C are cross-sectional views of concentric gears having various modulator segment shapes according to aspects of the present disclosure. [Figure 24D] 1A-1C are cross-sectional views of concentric gears having various modulator segment shapes according to aspects of the present disclosure. [Figure 25A] FIG. 1 is a perspective view of an axial flux magnetic gear having a segmented modulator according to an aspect of the present disclosure. [Figure 25B] FIG. 1 illustrates a perspective view of a transverse flux magnetic gear having a segmented modulator according to an aspect of the present disclosure. [Figure 26] FIG. 2 is a cross-sectional view of a concentric magnetic gear having an angled modulator according to an aspect of the present disclosure. [Figure 27A] FIG. 1 illustrates a cross-sectional view of a concentric magnetic gear having an angled modulator configured to reduce unbalanced magnetic forces, according to an aspect of the present disclosure. [Figure 27B] FIG. 1 illustrates a cross-sectional view of a concentric magnetic gear having an angled modulator configured to reduce unbalanced magnetic forces, according to an aspect of the present disclosure. [Figure 27C] FIG. 1 illustrates a cross-sectional view of a concentric magnetic gear having an angled modulator configured to reduce unbalanced magnetic forces, according to an aspect of the present disclosure. [Figure 28A] FIG. 1 is a perspective view of an axial flux magnetic gear with an angled modulator according to an aspect of the present disclosure. [Figure 28B] FIG. 1 illustrates a perspective view of a transverse flux magnetic gear having an angled modulator according to an aspect of the present disclosure. [Figure 29A] FIG. 1 illustrates a cross-sectional view of a concentric magnetic gear having an angular modulator and features for ease of fabrication, according to aspects of the present disclosure. [Figure 29B] FIG. 1 illustrates a cross-sectional view of a concentric magnetic gear having an angular modulator and features for ease of fabrication, according to aspects of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] It should be understood that the following disclosure provides many different embodiments or examples for implementing various features of the various embodiments. Specific examples of components and arrangements are described below to simplify the disclosure. Of course, these are examples only and are not intended to be limiting. The section headings used herein are for organizational purposes and should not be construed as limiting the subject matter described.

[0022] Harmonic drives and cycloidal drives are the most common mechanical gearboxes used to achieve high torque density at higher gear ratios (often greater than 30:1). Cycloidal magnetic gears were developed in an attempt to increase reliability and torque density compared to their mechanical counterparts.

[0023] While all types of magnetic gears offer potential advantages over mechanical gears, such as improved reliability, reduced maintenance, reduced acoustic noise, and inherent overload protection, other magnetic gear topologies, such as coaxial magnetic gears, are limited to relatively low gear ratios. Cycloidal magnetic gears can achieve high torque density at relatively high gear ratios. The use of multiple rotors reduces challenges associated with cycloidal magnetic gears, including, but not limited to, balancing the center of mass about the axis of rotation, balancing radial magnetic forces, and canceling off-axis moments, which would occur if only two rotor segments were used or if the rotor segments were all equal in length.

[0024] Similar to cycloidal mechanical gears, the inner rotor of a cycloidal magnetic gear is parallel to the axis of the outer rotor, but offset from this axis, and moves in an orbital revolution about the stationary central axis of the outer rotor. This orbital revolution rotates the air gap permeance function, thereby modulating the spatial flux harmonics to facilitate the gearing behavior. The orbital revolution is connected to a high speed shaft. Although the low speed rotation can be provided by either the inner or outer rotor rotating about its own axis, various embodiments disclosed herein keep the outer rotor stationary and connect the inner rotor rotating about its own axis to a low speed shaft. It should be noted that as used herein, input can be interchangeable with high speed (e.g., the input shaft can be the high speed shaft) and output can be interchangeable with low speed (e.g., the output shaft can be the low speed shaft). The terms can be interchangeable throughout this disclosure, and various applications require the input component to be the high speed component or the output component to be the low speed component.

[0025] FIG. 1 is a cross-sectional view of a magnetocycloid gear 100. The magnetocycloid gear 100 includes an outer rotor 102, a first inner rotor 104, a second inner rotor 106, and a third inner rotor 108. In various embodiments, the outer rotor 102 remains stationary during operation, but in various embodiments, the outer rotor 102 may rotate. A first plurality of magnetic pole pairs 110 are arranged in a linear fashion around an inner circumference of the outer rotor 102. The first inner rotor 104, the second inner rotor 106, and the third inner rotor 108 are disposed within the outer rotor 102. In various embodiments, the first inner rotor 104, the second inner rotor 106, and the third inner rotor 108 are connected to an input shaft 202 (shown in FIG. 2). The input shaft 202 is aligned with a central axis of the outer rotor 102. The axes of rotation of the first inner rotor 104 and the third inner rotor 108 are offset from the central axis to a first side of the input shaft 202, and the second inner rotor 106 is offset from the central axis to a second side of the input shaft 202, opposite the first side. Thus, the first inner rotor 104, second inner rotor 106, and third inner rotor 108 orbit about the central axis of the outer rotor 102 in addition to rotating about each of their respective central axes.

[0026] 1 , a second plurality of pole pairs 116 are disposed on the outer periphery of the first inner rotor 104. A third plurality of pole pairs 118 are disposed on the outer periphery of the second inner rotor 106, and a fourth plurality of pole pairs 120 are disposed on the outer periphery of the third inner rotor 108. The second plurality of pole pairs 116, the third plurality of pole pairs 118, and the fourth plurality of pole pairs 120 interact with the first plurality of pole pairs 110. In various embodiments, the fifth plurality of pole pairs 112 and the sixth plurality of pole pairs 114 are arranged in a linear fashion around the inner periphery of the outer rotor 102 such that the first plurality of pole pairs 110, the fifth plurality of pole pairs 112, and the sixth plurality of pole pairs 114 are parallel to one another. In such an embodiment, the second plurality of magnetic pole pairs 116 interact with the first plurality of magnetic pole pairs 110, the third plurality of magnetic pole pairs 118 interact with the fifth plurality of magnetic pole pairs 112, and the fourth plurality of magnetic pole pairs 120 interact with the sixth plurality of magnetic pole pairs 114.

[0027] Still referring to FIG. 1 , the first inner rotor 104 and the third inner rotor 108 each have approximately half the thickness of the second inner rotor 106. Thus, the second inner rotor 106 has approximately twice the mass of the individual first inner rotor 104 and the third inner rotor 108. Additionally, the first inner rotor 104 and the third inner rotor 108 both orbit about the input shaft 202. The second inner rotor 106 orbits about the input shaft in the same rotational direction as the first inner rotor 103 and the third inner rotor 108, but on the opposite side of the input shaft from the first inner rotor 104 and the third inner rotor 108. Such an arrangement counteracts off-axis moments acting on the input shaft 202 in addition to balancing the masses and forces on the input shaft 202. Such an arrangement reduces vibrations and reduces stress on the magnetocycloid gear 100 during operation.

[0028] In various embodiments, the first plurality of pole pairs 110, the second plurality of pole pairs 116, the third plurality of pole pairs 118, the fourth plurality of pole pairs 120, the fifth plurality of pole pairs 112, and the sixth plurality of pole pairs 114 may be formed, for example, from permanent magnets, such as those including rare earth elements or ferrites, for example. The outer rotor 102, the first inner rotor 104, the second inner rotor 106, and the third inner rotor 108 may be formed, for example, from magnetically permeable steel, soft magnetic compositions, carbon fiber reinforced polymer, magnetically impermeable steel, aluminum, fiberglass, or plastic, for example. In various embodiments, the first plurality of pole pairs 110, the second plurality of pole pairs 116, the third plurality of pole pairs 118, the fourth plurality of pole pairs 120, the fifth plurality of pole pairs 112, and the sixth plurality of pole pairs 114 include aligned adjacent permanent magnets. The permanent magnets are arranged in an alternating magnetic polarity pattern such that each permanent magnet has an opposite magnetic polarity to the adjacent permanent magnets on either side. Thus, the first plurality of magnetic pole pairs 110, the second plurality of magnetic pole pairs 116, the third plurality of magnetic pole pairs 118, the fourth plurality of magnetic pole pairs 120, the fifth plurality of magnetic pole pairs 112, and the sixth plurality of magnetic pole pairs 114 include permanent magnets arranged in a N, S, N, S, etc. pattern.

[0029] FIG. 2 is a series of diagrams illustrating the orbital motion of the inner rotor relative to the rotation of the inner rotor. For purposes of discussion, the inner rotor shown in FIG. 2 is described as the first inner rotor 104, however, the second inner rotor 106 and the third inner rotor 108 follow the same motion pattern. Line 204 shows the rotational position of the first inner rotor 104. As the first inner rotor 104 progresses through one orbital revolution as shown in steps 1-9, the first inner rotor 104 rotates about its own axis. Thus, when the first inner rotor 104 completes one full orbital revolution, the first inner rotor 104 will have rotated one pole pair relative to the outer rotor 102. In various embodiments, the rotation of the first inner rotor 104 drives an output shaft (not explicitly shown).

[0030] 3A is a cross-sectional view of a cycloidal magnetic gear 300 utilizing a consequent pole arrangement. The cycloidal magnetic gear 300 includes an outer rotor 302, a first inner rotor 304, a second inner rotor 306 (shown in FIG. 4), and a third inner rotor 307 (shown in FIG. 4). In various embodiments, the outer rotor 302, the first inner rotor 304, the second inner rotor 306, and the third inner rotor 307 of the cycloidal magnetic gear 300 are arranged similarly to the outer rotor 102, the first inner rotor 104, the second inner rotor 106, and the third inner rotor 108 of the cycloidal magnetic gear 100. For simplicity of discussion, the structure of the first inner rotor 304 is described, but the structures of the second inner rotor 306 and the third inner rotor 307 of the cycloidal magnetic gear 300 are similar. In various embodiments, a cycloidal magnetic gear 300 utilizing a consequent pole arrangement may include a single inner rotor 304 (consequential poles do not need to have multiple rotor segments).

[0031] Still referring to FIG. 3A, the outer rotor 302 includes a plurality of teeth 308 formed around the inner circumference. Permanent magnets 310 are disposed between the teeth 308. In various embodiments, the permanent magnets 310 are of the same magnetic polarity. As a result of the permanent magnets 310, the teeth 308 are magnetized with opposite polarity. In various embodiments, the teeth 308 may be arranged to hold the permanent magnets 310 in place. For example, in the embodiment shown in FIG. 3A, the teeth 308 include tapered edges 312. The tapered edges 312 secure the permanent magnets 310, eliminating the need for additional magnet retention mechanisms such as, for example, a retaining sleeve. In various embodiments, the teeth 308 may be constructed to be narrower than the permanent magnets 310. Such an arrangement facilitates the use of wider, more easily manufactured permanent magnets 310. This is especially true for cycloidal magnetic gears, which have high gear ratios and therefore require a large number of pole pairs. In various embodiments, the cycloidal magnetic gear 300 may utilize less permanent magnet material than a surface permanent magnet configuration having the same gear ratio, such as that utilized in the cycloidal magnetic gear 100.

[0032] Still referring to FIG. 3A, the consequent pole type configuration is similar to the surface permanent magnet cycloidal magnetic gear, but the NS permanent magnet pole pair (two permanent magnets) is replaced with an N tooth or S tooth pair (one permanent magnet and one ferromagnetic tooth). As a result of the permanent magnet 310, the ferromagnetic tooth 308 becomes magnetically poled with the opposite polarity. Thus, the permanent magnet 310 magnetizes the tooth 308. In various embodiments, the geometry of the tooth 308 and the permanent magnet 310 can be modified so that the tooth 308 holds the permanent magnet 310 in place. In various embodiments, the tooth 308 and the permanent magnet 310 are of unequal size. As shown in FIG. 3B, in various embodiments, the permanent magnet 310 can span more than half the pole pair arc, and thus the arc length of the permanent magnet 310 can be greater than the arc length of the tooth 308. As also shown in Figure 3B, keyways, splines, grooves, or flux barriers 314 may be implemented behind the teeth 308 in various embodiments. As shown in Figure 3C, for the outer rotor 302, in various embodiments, the teeth 308 themselves or the space behind the teeth 308 in the back-iron 313 may be utilized as a location for through holes 316 that allow structural material 318, such as bolts or screws, to facilitate attachment of the cycloidal magnetic gear 300. As an alternative embodiment, as shown in Figure 3D, the inner rotor 304 may remain consequent pole while the outer rotor 302 may be of the surface permanent magnet type, or vice versa, to generate more magnetic flux in the air gap.

[0033] 3E is a schematic diagram of a cycloidal magnetic gear 350 utilizing an axial magnetization consequent pole placement configuration. The cycloidal magnetic gear 350 includes a first rotor 352 and a second rotor 354. A plurality of magnetic pole pairs 356 are disposed on an axial surface of the first rotor 352. A plurality of permanent magnets 358 are disposed on an axial surface of the second rotor 354, and a plurality of ferromagnetic teeth 360 are disposed between successive permanent magnets 358 of the plurality of permanent magnets 358. During operation, the plurality of permanent magnets 358 cause the plurality of ferromagnetic teeth 360 to be consequently magnetized with a polarity opposite to that of the plurality of permanent magnets 358. The first rotor 352 is aligned with the second rotor 354 in an axial manner such that a plurality of magnetic pole pairs 356 of the first rotor 352 interact with a plurality of permanent magnets 358 and a plurality of ferromagnetic teeth 360 due to axial magnetic flux relative to the first rotor 352 and the second rotor 354.

[0034] FIG. 4 is an exploded view of a cycloidal magnetic gear 400 utilizing both radially magnetized magnets and axially magnetized magnets. In various embodiments, the axially magnetized magnets 402 are utilized to magnetize the teeth 308 and create consequent poles. In various embodiments, the radially magnetized permanent magnets 310 may be eliminated and the axially magnetized permanent magnets 402 may be utilized. Such an arrangement may simplify the magnetization of the axially magnetized permanent magnets 402 and simplify the assembly of the cycloidal magnetic gear 400. As shown in FIG. 4, a hybrid arrangement including both the axially magnetized permanent magnets 402 and the radially magnetized permanent magnets 310 may be utilized. In various embodiments, any combination of the axially magnetized permanent magnets 402 and the radially magnetized permanent magnets 310 may be utilized. By using both the axially magnetized permanent magnets 402 and the radially magnetized permanent magnets 310, the torque density and / or specific torque of the cycloidal magnetic gear 400 may be increased. In various embodiments, different axial magnetization directions may be used (either both magnetized in the same direction or both magnetized in opposite directions). Any combination of any of the scenarios for the inner rotor 304 and the outer rotor 302 is possible. This embodiment may persist through any number of axial segments greater than or equal to two.

[0035] Alternatively, magnets may be embedded in one or both of the inner and outer rotors 304 and 302 rather than mounted on their respective surfaces. An internal permanent magnet configuration simplifies assembly because the magnets can be inserted into slots in the rotors rather than requiring them to be fixed to the rotor's surface, and the internal permanent magnet configuration may provide some reluctance torque in addition to traditional reactance torque. The magnets in the internal permanent magnet rotor may be arranged in a variety of configurations, including (but not limited to) V, U, and double V, as in an internal permanent magnet motor.

[0036] 5 is a flow chart illustrating a process 500 for assembling the cycloidal magnetic gear 100. The process 500 begins at step 502. At step 504, a first plurality of magnetic pole pairs 110 are disposed around an inner circumference of the outer rotor 102. At step 506, the first inner rotor 104, the second inner rotor 106, and the third inner rotor 108 are coupled to the input shaft 202. At step 508, a second plurality of magnetic pole pairs 116 are disposed on an outer circumference of the first inner rotor 104, a third plurality of magnetic pole pairs 118 are disposed on an outer circumference of the second inner rotor 106, and a fourth plurality of magnetic pole pairs 120 are disposed on an outer circumference of the third inner rotor 108. In various embodiments, the first inner rotor 104 and the third inner rotor 108 are positioned such that the first inner rotor 104 and the third inner rotor 108 are offset from the central axis of the outer rotor 102 toward a first side, and the second inner rotor 106 is positioned such that the second inner rotor is offset from the central axis of the outer rotor 102 toward a second side. In various embodiments, a fifth plurality of pole pairs 112 and a sixth plurality of pole pairs 114 are disposed around an inner circumference of the outer rotor 102 parallel to the first plurality of pole pairs 110. In such embodiments, the second plurality of pole pairs 116 interact with the first plurality of pole pairs, the third plurality of pole pairs 118 interact with the third plurality of pole pairs 120 interact with the fifth plurality of pole pairs 112, and the fourth plurality of pole pairs 120 interact with the sixth plurality of pole pairs 114. In step 510, the first inner rotor 104, the second inner rotor 106, and the third inner rotor 108 are positioned within the outer rotor 102. The process 500 ends in step 512. For purposes of discussion, the above-referenced steps 504-510 do not have to be performed in the order discussed herein, and in various embodiments, steps 504-510 may be performed in any order.

[0037] FIG. 6 is a cross-sectional view of an inner rotor 600 that may be used with, for example, the magnetocycloid gear 100. FIG. 7 is an exploded view of the inner rotor 600. FIG. 8 is a perspective view of the inner rotor 600. With reference collectively to FIGS. 6-8, the inner rotor 600 includes a back core 602 and a plurality of permanent magnets 604 attached to a surface of the back core 602. A plurality of spacers 606 are disposed across a surface of the back core 602. Each spacer of the plurality of spacers 606 is positioned between successive magnets of the plurality of permanent magnets 604 and extends radially from the back core 602. In various embodiments, the plurality of spacers 606 are constructed from a non-magnetic material. In various embodiments, the plurality of spacers 606 may be formed, for example, by cutting out the back core 602 to create a position for each magnet of the plurality of magnets 604. Thus, in such embodiments, the spacers 606 are formed in the area between successive positions of each magnet of the plurality of magnets 604. In other embodiments, the spacers 606 may be formed, for example, by bonding a non-magnetic web to the back core 602. As shown by way of example in FIG. 7, the spacers 606 may be inserted into grooves 608 formed in the back core 602. In such embodiments, the spacers 606 may be held in place relative to the back core 602 via frictional engagement with the back core 602 or via an adhesive, such as an epoxy. While FIGS. 6-8 show an inner rotor 600 by way of example, those skilled in the art will appreciate that the principles of the present disclosure may also be applied to the outer rotor of a cycloidal magnetic gear. Thus, the outer rotor may also be constructed with spacers positioned between successive permanent magnets.

[0038] FIG. 9 is a detailed view of a cycloidal magnetic gear 900 showing keyways 902 formed therein. In magnetic gear embodiments utilizing multiple mechanically phase-shifted rotor segments, successive rotors are magnetically phase-shifted relative to one another to maintain balance. To facilitate mechanical and magnetic phase shifting during assembly and maintain the shifting during operation, aspects of the disclosure involve using any type of keyways 902 or splines, teeth, etc. (making the surface uneven) on the inner diameter of the combined inner rotor back-iron 602 and / or the outer diameter of the inner rotor cycloidal disk (hub). Alternatively, all magnets 604 of the same polarity may be positioned over all of the inner rotor keyway markings, but magnetic phase shifting may be maintained by alternating the polarity of the poles on the outer stator corresponding to each successive rotor. Keyways (or splines) 902 may also be used to facilitate a friction fit between the hub and back-iron 602, eliminating the need for adhesives to facilitate torque transfer to the inner rotor 600. In various embodiments, during the manufacture of a cycloidal magnetic gear having multiple rotor segments, a single rotor may be constructed and then split along a plane perpendicular to the axis of rotation to produce multiple properly aligned rotor segments.

[0039] 10 is a cross-sectional view of a two-stage cycloidal magnetic gear system 1000. The two-stage cycloidal magnetic gear system 1000 includes a first input shaft 1002 coupled to a first cycloidal magnetic gear 1004. The first cycloidal magnetic gear 1004 is coupled to a first output shaft 1006. The first output shaft 1006 is supported by a first bearing 1008 and a second bearing 1010. The first output shaft 1006 is coupled to a second input shaft 1012. The second input shaft 1012 is coupled to a second cycloidal magnetic gear 1014. The second input shaft 1012 is supported by a third bearing 1016 and a fourth bearing 1018.

[0040] FIG. 11 is a cross-sectional view of a two-stage cycloidal magnetic gear system 1100. The two-stage cycloidal magnetic gear system 1100 includes a first input shaft 1102 coupled to a first cycloidal magnetic gear 1104. The first cycloidal magnetic gear 1104 is coupled to a first output shaft 1106. The first output shaft 1106 is supported by a first bearing 1108 and a second bearing 1110. The first output shaft 1106 is coupled to a second cycloidal magnetic gear 1114. In various embodiments, the first bearing 1108 and the second bearing 1110 may be, for example, a ball bearing, a cylindrical roller bearing, or any other type of bearing. In various embodiments, the first cycloidal magnetic gear 1104 and the second cycloidal magnetic gear 1114 may be, for example, a single rotor cycloidal gear or a multi-rotor cycloidal gear.

[0041] 12A is a schematic diagram of a reluctance cycloidal magnetic gear. In a reluctance cycloidal magnetic gear 1200, no magnets are placed on either the inner rotor 1202 or the outer rotor 1204. In the embodiment shown in FIG. 12A, the magnets on the inner rotor 1202 are replaced with teeth 1206 and slots 1208, but in other embodiments, the magnets on the outer rotor 1204 may be replaced with teeth and slots. In various embodiments, this topology allows high gear ratios to be achieved with only about one-quarter the magnetic poles for the same gear ratio as a surface permanent magnet cycloidal design.

[0042] 12B is a schematic diagram of a reluctance-type cycloidal magnetic gear 1250 utilizing an axial magnetization arrangement. The cycloidal magnetic gear includes a first rotor 1252 and a second rotor 1254. A plurality of magnetic pole pairs 1256 are disposed on an axial surface of the first rotor 1252. A plurality of ferromagnetic teeth 1260 are formed on the second rotor 1254. During operation, the plurality of magnetic pole pairs 1256 affect the plurality of ferromagnetic teeth 1260 due to magnetic reluctance. The first rotor 1252 is aligned with the second rotor 1254 in an axial manner such that the plurality of magnetic pole pairs 1256 of the first rotor 1252 interact with the plurality of ferromagnetic teeth 1260 due to axial magnetic flux relative to the first rotor 1252 and the second rotor 1254.

[0043] FIG. 13 is a schematic diagram of a magnetocycloid gear with a keyway. In FIG. 13, a keyway 1210 for connecting to the inner rotor cycloid disk (hub) and then to the crankshaft may be placed behind the teeth as shown in FIG. 13. The key is placed at the thickest point of the rotor to avoid stress points on the rotor and to avoid interference with the magnetic flux. In other words, material is removed from the thickest part of the disk in the radial direction to minimize mechanical stress in the area of ​​the connection and to minimize interference with the magnetic flux.

[0044] FIG. 14 is a schematic diagram of a cycloidal magnetic gear 1400 having a magnetic flux shield 1402. During operation, the orbiting of the inner rotor 1406 around the inner circumference of the outer rotor 1408 causes the air gap 1404 between the inner rotor 1406 and the outer rotor 1408 to vary in width. The larger air gap is located on the side of the outer rotor 1408 opposite the closest interaction point between the inner rotor 1406 and the outer rotor 1408. In various embodiments, the magnetic flux shield 1402 is located in the larger portion of the air gap 1404 located between the inner rotor 1406 and the outer rotor 1408. In various embodiments, the magnetic flux shield 1402 may be radially opposite the narrowest portion of the air gap 1404 as shown in FIG. 14. In other embodiments, the magnetic flux shield 1402 may be offset by some angle from the point radially opposite the narrowest portion of the air gap 1404. The flux shield 1402 orbits about the main axis of rotation at the same speed as the high speed shaft. The flux shield 1402 is shaped to short out undesirable magnetic paths that may contribute to opposing torque generation on the inner rotor 1406. The flux shield 1402 may also be shaped to reduce radial loading on the bearings of the inner rotor 1406. In various embodiments, the flux shield 1402 itself may replace the counterweight or additional counterweighting may be used for final balance after including the flux shield 1402. In various embodiments, the flux shield 1402 may be utilized with various types of cycloidal magnetic gears including, for example, surface permanent magnet, consequent pole, internal permanent magnet, and reluctance type cycloidal magnetic gears.

[0045] 15 is a schematic diagram showing the force distribution on the inner rotor 1406 of the cycloidal magnetic gear at a particular moment. The magnetic interaction of the inner rotor 1406 with the outer rotor 1408 creates a torque acting on the inner rotor 1406. On one side of the inner rotor 1406, the torque has a positive value and acts in the same direction as the rotation of the inner rotor 1406. However, on the other side of the inner rotor 1406, the torque has a negative value and acts opposite to the direction of rotation of the inner rotor 1406. In operation, the flux shield 1402 counteracts the opposing forces that create counterproductive torque in the cycloidal magnetic gear 1400.

[0046] Since the flux shield 1402 will spin at the speed of the eccentric motion of the inner rotor 1406 driven by the input camshaft, the flux shield 1402 can be coupled to the input camshaft (not explicitly shown) in various embodiments. FIG. 16 is a perspective view of the flux shield 1702 cantilevered from a central hub 1704 by one or more webs 1706. In various embodiments, the central hub 1704 receives the input camshaft. As shown in FIG. 16, the flux shield 1702 may be cantilevered, but even with small stack lengths, such cantilevers result in large deflections. The webs 1706 and central hub 1704 that constrain the flux shield 1702 may be designed with mass removed (or added) such that the flux shield 1702 and associated structures act as a counterweight in various embodiments.

[0047] 17 is a perspective view of a flux shield assembly 1900 with added mass to act as a counterweight. The flux shield assembly 1900 includes a flux shield 1902 coupled to a central hub 1904 via a first plurality of webs 1906. A counterweight 1908 is disposed on an opposite side of the central hub 1904 from the flux shield 1902. The counterweight 1908 is separated from the central hub 1904 by a second plurality of webs 1910. In operation, the counterweight 1908 balances the mechanical forces exerted by the flux shield 1902 and prevents deflection of the flux shield 1902.

[0048] 18A is a perspective view of the flux shield 2020 with mass removed. The flux shield 2020 itself may not be a monolithic structure in various embodiments and may have mass removed in places to allow the flux shield 2020 to act as a static or dynamic counterbalance, thereby moving the center of gravity of the flux shield 2020 to the center of the input camshaft, as discussed below in connection with FIGS. 18B and 18C. The flux shield 2020 and the connection to the input shaft may be made from one solid object in various embodiments to increase structural integrity. However, in other embodiments, the flux shield and the connection to the input shaft may be non-integral.

[0049] FIG 18B is a cross-sectional view of a magnet gear with a shaft 2024 having a center 2026. FIG 18C shows a flux shield 2020 secured to the shaft 2024. The magnetic gear configuration in FIG 18B has a center of mass above or slightly above the center 2026. When the flux shield 2020 is secured to the shaft 2024, the center of mass is moved downward, closer to the center 2026. Thus, in some embodiments, the flux shield 2020 can be configured such that the center of mass is moved toward or at the center 2026.

[0050] 19 is a cross-sectional view of a radial magnetocycloid gear with a flux shield 802. An unstable equilibrium occurs because the flux shield 802 experiences radially inward and outward forces resulting from the magnetic interaction of the flux shield 802 with the inner rotor 806 and the outer rotor 808. To facilitate better assembly and a more robust design, the flux shield 802 may be intentionally offset in a larger air gap 2102, either intentionally closer to the outer rotor 808 or intentionally closer to the inner rotor 806. By being intentionally closer to either rotor, the flux shield 802 may experience large unbalanced forces. In various embodiments, such unbalanced forces can be exploited by interfacing the flux shield 802 with a bushing or bearing or ensuring good contact. The flux shield 802 or output pin disk (not explicitly shown) may, for example, be anodized, hardened, or may carry a bushing to facilitate smoother sliding in various embodiments.

[0051] FIG. 20 is a perspective view of the flux shield 2202 engaging the bearing gripping structure 2204 against the low speed shaft pin disk 2206 on the low speed shaft 2208. In various embodiments, the flux shield 2202 may also be partially mounted on the bearing gripping structure 2204. In various embodiments, the flux shield 2202 may also be on a bearing on the low speed shaft or housing as opposed to a large bearing on the low speed shaft pin disk 2206. Such an arrangement would couple the flux shield 2202 to the high speed camshaft and allow the flux shield 2202 to have a second interface with the low speed shaft 2208 via a bearing or bushing since those components rotate at different speeds or with the housing via a bearing or bushing. In this case, the flux shield 2202 may be intentionally offset closer to the inner rotor 806 to facilitate placement on the low speed shaft 2208 in various embodiments. Alternatively, the flux shield 2202 may be coupled to the input shaft and purposely offset closer to the outer rotor, with a bearing or bushing attachment connected to the outer rotor. Such an arrangement is useful in embodiments where the inner rotor is stationary about its own axis and the outer rotor rotates, where the outer rotor already requires a bushing / bearing. In some embodiments, there is typically a bearing on the low speed shaft 2208 and not on the low speed shaft pin disk 2206. In this arrangement, the magnetic flux essentially passes through the low speed pin disk 2206 and grips the bearing on the low speed shaft 2208.

[0052] While this particular embodiment describes a low speed shaft pin disk 2206, a low speed shaft 2208, and a high speed camshaft, it should be understood by one of ordinary skill in the art that the input shaft (and associated components) can be the high speed shaft (and associated components) and the low speed shaft (and associated components) can be the output shaft (and associated components). Thus, as used herein, input can be interchangeable with high speed (e.g., the input shaft can be the high speed shaft) and output can be interchangeable with low speed (e.g., the output shaft can be the low speed shaft). The terms can be interchangeable throughout this disclosure and various applications require that the input component be the high speed component or the output component be the low speed component.

[0053] 21 is a perspective view of a flux shield 2302 having a bearing lip 2304. In various embodiments, there are at least two locations where the flux shield 2302 can be secured. The first location may be through the coupling of the flux shield 2302 to the input shaft. The second location may use a feature to axially align to the second contact point in various embodiments. Such an arrangement may utilize, for example, a flange or lip 2304 on the bearing 2306 or a bushing on the inner or outer rotor in various embodiments. To have this type of lip, the apparatus for the flux shield 2302 is at least two pieces.

[0054] FIG. 22 is a perspective view of a system consisting of multiple flux shields 2402(1)-(2) and pin disks 2404(1)-(2). For cycloidal magnetic gears with long stack lengths, it may be advantageous to have multiple pin disks 2404(1)-(2) to avoid cantilevering the pins over such large lengths. In various embodiments, the outer diameter of the pin disks 2402(1)-(2) may have large, thick sections, as may the bearings. In this case, the body length of a single flux shield 2402(1)-(2) may be reduced, for example, by mechanically phase-shifting the flux shields 2402(1)-(2) after each pin disk section. Although an example with two pin disks 2404(1)-(2) and two flux shields 2402(1)-(2) is shown, in other embodiments, any number of pin disks and flux shields may be utilized.

[0055] However, if multiple pin disks are used, the flux shields 2402(1)-(2) may be closer to the inner rotor than the outer rotor such that the flux shields 2402(1)-(2) have a force pointing radially inward. In this case, as the cycloidal gears operate and the centrifugal force on the flux shields 2402(1)-(2) increases, the flux shields 2402(1)-(2) may still be magnetically attracted inward to better preload and rest on the bearings 2408.

[0056] 23 is a cross-sectional view of a concentric gear system 3800. The concentric gear system 3800 includes an inner back core 3802 having a first plurality of pole pairs 3804 disposed on an outer periphery. The inner back core 3802 and the first plurality of pole pairs 3804 are disposed within an outer back core 3806. The outer back core 3806 has a second plurality of pole pairs 3808 disposed on an inner periphery. A modulator 3810 is disposed between the first plurality of pole pairs 3804 and the second plurality of pole pairs 3808.

[0057] Still referring to FIG. 23 , the modulator 3810 includes a plurality of magnetically permeable segments 3812 arranged to alternate with a plurality of non-magnetic segments 3814. Thus, each magnetically permeable segment of the plurality of magnetically permeable segments 3812 is disposed between consecutive non-magnetic segments of the plurality of non-magnetic segments 3814. In various embodiments, each magnetically permeable segment of the plurality of magnetically permeable segments 3812 and each non-magnetic segment of the plurality of non-magnetic segments 3814 is formed by a protrusion 3816 extending outwardly from a first end and a recess 3818 extending inwardly from a second end. In various embodiments, the protrusion 3816 and the recess 3818 facilitate coupling of the plurality of magnetically permeable segments 3812 with the plurality of non-magnetic segments 3814. In various embodiments, such an arrangement facilitates easy assembly of the modulator 3810. Additionally, the plurality of magnetic segments 3812 and the plurality of non-magnetic segments 3814 prevent choking of magnetic flux and the formation of short magnetic flux leakage paths between the segments of the modulator 3810.

[0058] In various embodiments, the protrusions 3816 and depressions 3818 may have various shapes. Figure 24A shows that the protrusions 3816 and depressions 3818 may extend the entire radial length of the segment of the modulator 3810. Figure 24B shows that the protrusions 3816 and depressions 3818 may extend a partial radial length of the segment of the modulator 3810. Figure 24C shows that the protrusions 3816 and depressions 3818 may have an elliptical shape. Figure 24D shows that the protrusions 3816 and depressions 3818 may be utilized with other support mechanisms, such as, for example, bridges 3820.

[0059] In various embodiments, a modulator 3810 of the type described in connection with Figure 23 may be utilized with other magnetic gear topologies. Figure 25A shows an axial flux magnetic gear having a modulator 3902 having a permeable segment 3904 with protrusions 3906 and recesses 3908. Figure 25B shows a transverse flux magnetic gear 3950 having a modulator 3952 having a permeable segment 3954 with protrusions 3956 and recesses 3958. In Figures 25A and 25B, the non-magnetic segments of the modulators (3902, 3952) have been omitted for clarity.

[0060] FIG. 26 is a cross-sectional view of a concentric magnetic gear 4000 with shaped modulator segments 4002. A flux modulator 4001 includes multiple modulator segments 4002. In various embodiments, each modulator segment of the multiple modulator segments 4002 maps an electromagnetic angle from a first plurality of magnetic pole pairs 3804 to a second plurality of magnetic pole pairs 3808. The number of modulator segments 4002 need not be related to the number of pole pairs in the first plurality of magnetic pole pairs 3804 or the second plurality of magnetic pole pairs 3808. In various embodiments, a single gear may have multiple modulator segments 4002 with multiple different shapes. In various embodiments, the modulator segments 4002 may be arranged to reduce or eliminate unbalanced magnetic forces acting on either the first plurality of magnetic pole pairs 3804 or the second plurality of magnetic pole pairs 3808. FIG. 27A shows a modulator 4051 with two sections of modulator segments 4002. FIG. 27B illustrates a modulator 4061 having three sections of modulator segments 4002. FIG. 27C illustrates a modulator 4071 having four sections of modulator segments 4002. Although FIGS. 26-27C illustrate modulators having one to four sections of modular segments, in some embodiments, any number of sections of modular segments can be utilized. In various embodiments, the modulator segments 4002 may be applied to other magnetic gear topologies. FIG. 28A illustrates an axial flux magnetic gear 4200 having modulator segments 4002 each mapping an electromagnetic angle from a first plurality of magnetic pole pairs (e.g., first plurality of magnetic pole pairs 3804 of FIG. 26) to a second plurality of magnetic pole pairs (e.g., second plurality of magnetic pole pairs 3808 of FIG. 26). FIG. 28B shows a transverse flux magnetic gear 4250 having modulator segments 4002 that each map an electromagnetic angle from a first plurality of pole pairs (e.g., first plurality of pole pairs 3804 of FIG. 26) to a second plurality of pole pairs (e.g., second plurality of pole pairs 3808 of FIG. 26).

[0061] 29A-29B show embodiments of a modulator 4300 that is designed with features for ease of fabrication. In various embodiments, the modulator is fabricated with a bridge 4302, as shown in FIG. 29A, where the gaps between the modulator segments 4002 are then filled with, for example, a non-magnetic material. In various embodiments, the bridge can then be machined to create a modulator 4300 with multiple modulator segments 4002. In some embodiments, each modulator segment may have a protrusion on one side and a recess on the other side, as shown in FIG. 29B.

[0062] In various embodiments, the front low pole rotor of the axial flux coaxial magnetic gear is the high speed rotor, the rear high pole rotor of the axial flux coaxial magnetic gear is fixed, and the modulator is left as the free-rotating low speed rotor. Alternatively, the modulator may be fixed and the high pole rear rotor may act as the low speed rotor. For all magnetic gears including the 8th, 9th, and 10th technologies, each rotor may include surface permanent magnets of conventional or Halbach topology, or may be of consequent pole, flux focusing, or reluctance topology.

[0063] In various embodiments, magnetic gears offer the potential advantages over mechanical gears of improved reliability, reduced maintenance, reduced acoustic noise, and inherent overload protection. Cycloidal magnetic gearboxes with multiple rotors are capable of achieving very high gear ratios, which are of particular interest to industries such as wind or wave energy conversion, space traction or actuation, or robotics for automation.

[0064] Although various embodiments of the present disclosure are illustrated in the accompanying drawings and described in the above detailed description, it will be understood that the disclosure is not limited to the embodiments disclosed herein, but rather is capable of numerous rearrangements, modifications, and substitutions without departing from the spirit of the disclosure as set forth herein.

[0065] The term "substantially" is defined as roughly, but not necessarily completely, what is specified, as would be understood by one of ordinary skill in the art. In any disclosed embodiment, the terms "substantially," "approximately," "generally," and "about" may be substituted with "within [a percentage] of" what is specified, where percentages include 0.1, 1, 5, and 10 percent.

[0066] The above outlines features of some embodiments to enable those skilled in the art to better understand aspects of the present disclosure. It will be appreciated by those skilled in the art that they can readily use the present disclosure as a basis for designing or modifying other processes and structures to carry out the same purposes and / or achieve the same advantages of the embodiments presented herein. It will also be appreciated by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that various changes, substitutions, and alterations can be made herein without departing from the spirit and scope of the present disclosure. The scope of the present invention is to be determined solely by the language of the appended claims. The term "comprising" in the claims is intended to mean "including at least" such that the recited enumeration of elements in the claims is an open group. The terms "a," "an," and other singular terms are intended to include the plurals thereof unless expressly excluded.

Claims

1. A cycloid magnetic gear, An outer rotor; a first plurality of pole pairs disposed on an inner circumference of the outer rotor; a first inner rotor disposed within the outer rotor, the first inner rotor having a second plurality of magnetic pole pairs disposed on an outer periphery; a second inner rotor disposed within the outer rotor, the second inner rotor having a third plurality of pole pairs disposed on an outer periphery; a third inner rotor disposed within the outer rotor, the third inner rotor having a fourth plurality of magnetic pole pairs disposed on an outer periphery; Equipped with the first inner rotor and the third inner rotor have approximately half the thickness of the second inner rotor; The first inner rotor, the second inner rotor, and the third inner rotor balance a moment acting on a drive shaft.

2. The cycloidal magnetic gear of claim 1 , wherein the outer rotor is stationary.

3. 2. The cycloidal magnetic gear according to claim 1, wherein the first inner rotor, the second inner rotor, and the third inner rotor orbit about a central axis of the outer rotor.

4. 4. The cycloidal magnetic gear of claim 3, wherein the first inner rotor, the second inner rotor, and the third inner rotor are coupled to an input shaft, the input shaft being aligned with the central axis of the outer rotor.

5. 5. The cycloidal magnetic gear of claim 4, wherein the first inner rotor and the third inner rotor are offset from the central axis of the outer rotor toward a first side of the input shaft.

6. 6. The cycloidal magnetic gear of claim 5, wherein the second inner rotor is offset from the central axis of the outer rotor toward a second side of the input shaft.

7. 7. The cycloidal magnetic gear of claim 6, wherein the offset arrangement of the first inner rotor, the second inner rotor, and the third inner rotor balances masses and forces acting on the input shaft.

8. the first inner rotor rotates about a central axis of the first inner rotor; the second inner rotor rotates about a central axis of the second inner rotor; The cycloidal magnetic gear according to claim 3 , wherein the third inner rotor rotates about a central axis of the third inner rotor.

9. 9. The cycloidal magnetic gear of claim 8, wherein rotation of the first inner rotor, the second inner rotor, and the third inner rotor drives a low speed shaft.

10. a fifth plurality of pole pairs disposed about an inner circumference of the outer rotor parallel to the first plurality of pole pairs; a sixth plurality of pole pairs disposed about an inner circumference of the outer rotor parallel to the first plurality of pole pairs; The cycloidal magnetic gear according to claim 1 .

11. the second plurality of magnetic pole pairs interacting with the first plurality of magnetic pole pairs; the third plurality of pole pairs interacting with the fifth plurality of pole pairs; The cycloidal magnetic gear of claim 10 , wherein the fourth plurality of pole pairs interact with the sixth plurality of pole pairs.

12. 12. The cycloidal magnetic gear according to claim 11, wherein the first inner rotor rotates one pole pair relative to the outer rotor for each revolution of the first inner rotor about a central axis of the outer rotor.

13. A method for assembling a cycloidal magnetic gear, comprising the steps of: coupling the first plurality of pole pairs, the second plurality of pole pairs, and the third plurality of poles to an inner circumference of an outer rotor; coupling the first inner rotor, the second inner rotor, and the third inner rotor to an input shaft; coupling a fourth plurality of pole pairs to the first inner rotor, a fifth plurality of pole pairs to the second inner rotor, and a sixth plurality of pole pairs to the third inner rotor; disposing the first inner rotor, the second inner rotor, and the third inner rotor within the outer rotor such that the fourth plurality of pole pairs interact with the first plurality of pole pairs, the fifth plurality of pole pairs interact with the second plurality of pole pairs, and the sixth plurality of pole pairs interact with a third plurality of pole pairs; A method comprising:

14. A cycloid magnetic gear, An outer rotor; a first plurality of teeth formed in the outer rotor; a first plurality of permanent magnets disposed between adjacent ones of the plurality of teeth of the outer rotor; a first inner rotor disposed within the outer rotor, the first inner rotor having a second plurality of teeth formed on an outer periphery, a second plurality of permanent magnets being disposed between adjacent ones of the second plurality of teeth; a second inner rotor disposed within the outer rotor, the second inner rotor having a third plurality of teeth formed on an outer periphery, a third plurality of permanent magnets being disposed between adjacent ones of the third plurality of teeth; a third inner rotor disposed within the outer rotor, the third inner rotor having a fourth plurality of teeth formed on an outer periphery, a fourth plurality of permanent magnets being disposed between adjacent ones of the fourth plurality of teeth; Equipped with the first inner rotor and the third inner rotor have an axial length that is approximately half the thickness of the second inner rotor; The first inner rotor, the second inner rotor, and the third inner rotor balance a moment acting on a drive shaft.

15. A cycloid magnetic gear, A first rotor, a first rotor including at least one of a plurality of magnetic pole pairs disposed on the first rotor, or a plurality of first rotor permanent magnets disposed on the first rotor and a plurality of first rotor ferromagnetic teeth formed on the first rotor, each tooth of the plurality of first rotor ferromagnetic teeth being disposed between successive magnets of the plurality of first rotor permanent magnets, and the plurality of first rotor ferromagnetic teeth being consequently magnetized by the plurality of first rotor permanent magnets; A second rotor; and A plurality of permanent magnets disposed on the second rotor; a plurality of ferromagnetic teeth formed on the second rotor, each tooth of the plurality of ferromagnetic teeth being disposed between successive magnets of the plurality of permanent magnets; Equipped with A cycloidal magnetic gear, wherein the plurality of ferromagnetic teeth are consequently magnetized by the plurality of permanent magnets.

16. A cycloid magnetic gear, A first rotor; A second rotor; and A plurality of magnetic pole pairs disposed on the first rotor; a plurality of ferromagnetic teeth formed on the second rotor; Equipped with The second rotor interacts with the first rotor due to magnetic reluctance.

17. 17. The cycloidal magnetic gear of claim 16, wherein a plurality of notches are defined in the second rotor between consecutive ones of the plurality of ferromagnetic teeth.

18. the first rotor and the second rotor are radially arranged relative to one another such that the first rotor is an outer rotor and the second rotor is an inner rotor; the plurality of pole pairs are arranged around a circumference of the outer rotor in a radial arrangement; 17. The cycloidal magnetic gear of claim 16, wherein the plurality of ferromagnetic teeth are formed around a circumference of the inner rotor in a radial arrangement.

19. 20. The cycloidal magnetic gear according to claim 18, further comprising a through hole formed through or behind one of the plurality of ferromagnetic teeth.

20. 20. The cycloidal magnetic gear of claim 18, comprising a keyway formed in the inner rotor, the keyway facilitating alignment of the inner rotor.

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