Horizontal flux motor

Abstract

A transverse flux motor is formed by a stator section and a rotor section. The stator section includes one or more phase assemblies formed by flux ring plates that axially clamp coil wire windings. The flux rings include teeth that magnetically interact with circumferentially opposite and adjacent teeth to form a flux path transverse to the axis of rotation of the rotor assembly.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 62 / 972,609, filed February 10, 2020, entitled “TOOTHASSEMBLY FOR A TRANSVERSE FLUX ELECTRIC MACHINE EMPLOYING A LAMINATION STACKHAVING A TOOTH TRENCH WITH A TOOTH SPRING GEOMETRY”; and claims the benefit of U.S. Provisional Application No. 62 / 972,615, filed February 10, 2020, entitled “MULTIPHASE TRANSVERSE FLUX ELECTRIC MACHINE EMPLOYING A SINGLE LAMINATION”. The applicant claims the rights to "GEOMETRY (a multiphase transverse flux motor employing a single laminate geometry)"; and to "LAMINATION RINGS WITH RETURN GAPS FOR COIL RETURN AND TRANSVERSE FLUX ELECTRIC MACHINE INCORPORATING SAME (a transverse flux motor having a laminate ring with return gaps for coil return and incorporating the laminate ring)" filed on February 10, 2020; and to "TRANSVERSE FLUX ELECTRIC MACHINE WITH POTTING DIMPLES AND METHOD OF PRODUCING" filed on February 10, 2020. The rights to SAME (Transverse Flux Motor with Potting Dents and Method of Manufacturing the Same) are claimed; and the rights to U.S. Provisional Application No. 62 / 972,629, filed February 10, 2020, entitled “CONTINUOUSLY TAPEREDTOOTH AND PHASE ASSEMBLIES WITH CONSTANT TOOTH OFFSET DISTANCES BETWEEN THECONTINUOUSLY TAPERED TEETH (Continuously Tapered Teeth and Phase Assembly with Constant Tooth Offset Distance Between the Continuously Tapered Teeth), the disclosures of which are incorporated herein by reference in their entirety. Background Technology

[0003] This disclosure generally relates to electric motors. More specifically, this disclosure relates to transverse flux motors.

[0004] Electric motors use electricity to produce mechanical output. Some electric motors produce rotational output. In an alternating current (AC) induction motor, the stator is energized to electromagnetically drive the rotor to rotate about the motor axis. The stator includes laminates and windings. The rotor includes permanent magnets that are rotated by an electromagnetic field induced by the current flowing through the stator. Such electric motors include coils that extend axially relative to the axis of rotation and extend beyond the ends of the rotor to wind around and form the ends of the coil windings.

[0005] Each coil represents a potential pole acting on a magnet. Discrete coils arranged circumferentially around the axis of rotation are out of phase with respect to each other. The resulting potential torque is proportional to the number of poles. The number of poles in such a motor is limited by the ability to assemble discrete coils circumferentially around the axis of rotation within the motor. The coil windings can be made smaller, and the stator diameter can be made larger to accommodate more coils to support more poles, but this increases the size, weight, and cost of the motor, and there are still limitations. Power can also be increased when the rotor rotates at a relatively high speed, allowing more coil-magnet to pass through per unit time. This requires the motor to operate at relatively high speeds, but some applications may expect lower speed outputs. Summary of the Invention

[0006] According to one aspect of this disclosure, an electric motor includes a stator and a rotor. The stator includes at least one phase assembly. The phase assembly includes a flux ring having a plurality of flux protrusions extending radially relative to the rotation axis of the rotor.

[0007] According to one aspect of this disclosure, an electric motor configured to generate a rotary output includes a rotor and a stator, the rotor being configured to rotate on a motor axis; the stator being configured to be energized to generate a magnetic flux that causes the rotor to rotate. The stator includes a flux ring, the flux ring including a coil and a plurality of flux protrusions extending radially from the coil and arranged circumferentially around the motor axis. A first flux protrusion of the plurality of flux protrusions includes a first retainer and a first tooth, the first tooth being at least partially disposed within the first retainer and held by the first retainer on the flux ring.

[0008] According to an additional or alternative aspect of this disclosure, a flux ring for an electric motor includes: a ring body disposed about an axis; and a plurality of flux protrusions extending radially relative to the ring body. Each of the plurality of flux protrusions includes: a retainer having a retainer body extending radially relative to the ring body, a first finger extending from the retainer body, and a second finger extending from the retainer body; and a tooth at least partially disposed within a retaining cavity of the retainer. The first and second fingers apply a radial force to the tooth to clamp the tooth within the retaining cavity.

[0009] According to another additional or alternative aspect of this disclosure, a flux ring for use in a transverse flux electric motor includes: a ring body disposed about an axis; and a plurality of flux protrusions extending radially relative to the ring body. Each of the plurality of flux protrusions includes: a retainer having a retainer body extending radially relative to the ring body, the retainer defining a retaining cavity; and a tooth at least partially disposed within the retaining cavity of the retainer. The retaining cavity includes a radial opening at an end of the cavity opposite to the retainer body. The retaining cavity includes a U-shaped base portion having a first leg and a second leg, the first leg being inclined in a first circumferential direction, and the second leg being inclined in a second circumferential direction opposite to the first circumferential direction.

[0010] According to another additional or alternative aspect of this disclosure, a method of manufacturing a flux ring for use in a transverse flux electric motor includes: forming a flux ring from a stack of laminates, the flux ring having a coil and a plurality of retainers, the coil defining a motor axis, the plurality of retainers extending radially relative to the coil; aligning powder metal teeth with a receiving chamber of a first retainer of the plurality of retainers; axially moving the powder metal teeth relative to the flux ring such that the powder metal teeth travel through an axial opening in the receiving chamber and enter the retaining cavity; and applying a radial force toward the coil towards the powder metal teeth by a first finger of the first retainer and a second finger of the second retainer, and fixing the powder metal teeth in the receiving chamber by sitting them in the retaining cavity.

[0011] According to another additional or alternative aspect of this disclosure, a flux ring for forming a phase assembly of a transverse flux electric motor includes: a ring body disposed around a motor axis; a plurality of trunks extending radially from the ring body; a plurality of branches supported by the trunks and radially away from the body, such that a plurality of return openings are defined between the ring body and the branches; and a plurality of flux protrusions extending from the branches and radially away from the ring body, wherein a circumferentially spaced gap is formed between adjacent flux protrusions. The flux ring includes a first lateral portion and a second lateral portion, the first lateral portion being located on a first side of a flip axis orthogonal to the motor axis, and the second lateral portion being located on a second side of the motor axis. The return openings on the first lateral side and the return openings on the second lateral side are aligned about the flip axis. The flux protrusions on the first lateral side and the flux protrusions on the second lateral side are misaligned about the flip axis.

[0012] According to another additional or alternative aspect of this disclosure, a phase assembly for a transverse flux electric motor includes: a first flux ring disposed around a motor axis and having a plurality of radially extending first flux protrusions; a second flux ring disposed around the motor axis and having a plurality of radially extending second flux protrusions; a coil axially disposed between the first and second flux rings; and a plurality of axial return members extending axially between the first and second flux rings and extending into a plurality of first return member openings of the first flux ring and a plurality of second return member openings of the second flux ring. The first flux ring has a first configuration defining radial and circumferential positions for each of the plurality of first return member openings and the plurality of first flux protrusions. The second flux ring has a second configuration defining radial and circumferential positions for each of the plurality of second return member openings and the plurality of second flux protrusions. The first configuration is identical to the second configuration.

[0013] According to another additional or alternative aspect of this disclosure, a stator for a transverse flux electric motor includes a plurality of flux rings disposed along and arranged about a motor axis. Each of the plurality of flux rings includes: a ring body disposed about the motor axis; a plurality of trunks extending radially from the ring body; a plurality of branches supported by the trunks and radially away from the ring body, such that a plurality of return openings are formed between the ring body and the branches; and a plurality of flux protrusions extending radially from the branches and away from the ring body. Each of the plurality of flux rings has a common basic configuration defining the radial and circumferential positions of each of the plurality of return openings and the plurality of flux protrusions. A first flux ring is disposed in a first position relative to the motor axis. A second flux ring is disposed in a second position relative to the motor axis, the second position being rotatable about the motor axis relative to the first position.

[0014] According to another additional or alternative aspect of this disclosure, a flux ring for a phase assembly of a stator of a transverse flux electric motor includes: a ring body disposed around a motor axis; a plurality of trunks extending radially from the ring body; a plurality of branches supported by the plurality of trunks and radially away from the ring body, such that a plurality of return openings are formed between the ring body and the plurality of branches; a plurality of flux protrusions extending from the plurality of branches and radially away from the ring body; and a plurality of gaps, each gap being circumferentially disposed between adjacent flux protrusions among the plurality of flux protrusions. A first gap among the plurality of gaps is disposed between a first branch among the plurality of branches and a second branch among the plurality of branches to define a wire return opening between the first branch and the second branch.

[0015] According to another additional or alternative aspect of this disclosure, a flux ring for a phase assembly of the stator of a transverse flux electric motor includes: a ring body disposed around a motor axis; a plurality of trunks extending radially from the ring body; a plurality of branches supported by the trunks and radially away from the ring body, such that a plurality of return openings are formed between the ring body and the branches; a plurality of flux protrusions extending from the branches and radially away from the ring body; a first set of a plurality of gaps, each gap in the first set of gaps being circumferentially disposed between adjacent flux protrusions of the plurality of flux protrusions; and a second set of a plurality of gaps, each gap in the second set of gaps being circumferentially disposed between adjacent branches of the plurality of branches. The second set of gaps is asymmetrically disposed about the motor axis.

[0016] According to another additional or alternative aspect of this disclosure, a phase assembly for a transverse flux electric motor includes: a first flux ring disposed around a motor axis; a second flux ring axially spaced from the first flux ring; a coil axially disposed between the first and second flux rings; and a plurality of axial return members extending between the first and second flux rings, wherein each of the plurality of axial return members extends into a first return member opening of the first flux ring and a second return member opening of the second flux ring. The plurality of axial return members are asymmetrically disposed about the motor axis. A first coil connector of the coil extends from the coil and radially through a return gap formed between the first and second axial return members. A second coil connector of the coil extends from the coil and radially through the return gap.

[0017] According to another additional or alternative aspect of this disclosure, an electric motor includes: a rotor configured to rotate about a motor axis; a stator including a plurality of phase assemblies arranged along and about the motor axis; and an air gap radially disposed between the rotor and the stator. The air gap has a dimensional variation between the rotor and the stator.

[0018] According to another additional or alternative aspect of this disclosure, a potting assembly for applying potting compound to the stator of an electric motor, the stator being configured to be radially disposed between the stator and a rotor with an air gap to form the electric motor, the potting assembly comprising: a conformable member configured to abut against a surface of the stator exposed to the air gap; and a counter-member disposed on a radial side of the stator opposite to the conformable member, such that the stator is radially supported by the conformable member and the counter-member. The conformable member protrudes into a gap formed between flux collecting components of the stator to define a recess in the surface of the stator exposed to the air gap.

[0019] According to another additional or alternative aspect of this disclosure, an electric motor includes: a rotor configured to rotate about a motor axis; a stator including a plurality of phase assemblies arranged along and around the motor axis; and an air gap radially disposed between the rotor and the stator. A plurality of recesses are formed in the surface of the stator exposed to the air gap.

[0020] According to another additional or alternative aspect of this disclosure, an electric motor includes a rotor and a stator, the rotor rotating about a motor axis. The stator includes at least one phase. Each phase includes: a first flux ring including a plurality of first return member slots, a plurality of first flux protrusions, a first facing side, and a first remote side; a second flux ring including a plurality of second return member slots, a plurality of second flux protrusions, a second facing side, and a second remote side, wherein the first flux ring and the second flux ring are positioned such that the plurality of first flux protrusions are circumferentially offset relative to the plurality of second flux protrusions; a plurality of return members arranged around the motor axis, each of the plurality of return members extending into one of the first return member slots and one of the plurality of second return member slots, such that each return member bridges between the first flux ring and the second flux ring; and a coil directly disposed between the first flux ring and the second flux ring such that the first facing side of the first flux ring faces the coil, and the second facing side of the second flux ring faces the coil. The positions of the plurality of first return slots and the plurality of first flux protrusions on the first flux ring relative to the motor axis are reverse mirror images of the positions of the plurality of second return slots and the plurality of second flux protrusions on the second flux ring.

[0021] According to another additional or alternative aspect of this disclosure, a method for assembling a first phase of an electric motor includes: positioning a first flux ring of a plurality of flux rings coaxial with a motor axis, wherein each of the plurality of flux rings has a plurality of return slots, a plurality of flux protrusions, a facing side, and a remote side; positioning a first side of a coil adjacent to the first flux ring and coaxial with the motor axis such that the facing side of the first flux ring faces the first side of the coil; and positioning a second flux ring of the plurality of flux rings coaxial with the motor axis and adjacent to the coil. The second flux ring is positioned such that its facing side faces the second side of the coil, and the coil is located directly between the first and second flux rings, and the plurality of flux protrusions of the first flux ring are circumferentially offset relative to the plurality of flux protrusions of the second flux ring; and a plurality of axial return members are inserted into the plurality of return member slots of the first and second flux rings such that each return member bridges between the first and second flux rings, and the plurality of axial return members are arranged around the axis of the electric motor.

[0022] According to another additional or alternative aspect of this disclosure, an electric motor includes: a rotor that rotates about a motor axis; and a stator including at least one phase. Each phase includes: a first flux loop including a first set of multiple trunks and a first set of multiple flux protrusions supported by the first set of multiple trunks, wherein the first set of multiple trunks are non-uniformly and circumferentially arranged about the motor axis; a second flux loop including a second set of multiple trunks and a second set of multiple flux protrusions supported by the second set of multiple trunks; and a coil coaxial with the motor axis and located directly between the first flux loop and the second flux loop, the coil being configured to be energized to electromagnetically polarize the flux of the first set of multiple flux protrusions relative to the second set of multiple flux protrusions.

[0023] According to another additional or alternative aspect of this disclosure, an electric motor includes: a rotor that rotates about a motor axis; and a stator including at least one phase. Each phase includes: a first flux ring including a first set of multiple branch groups and a first set of multiple flux protrusions supported by the first set of multiple branch groups, wherein the first set of multiple branch groups are non-uniformly and circumferentially arranged about the motor axis in respective branch groups; a second flux ring including a second set of multiple branch groups and a second set of multiple flux protrusions supported by the second set of multiple branch groups; and a coil coaxial with the motor axis and located directly between the first flux ring and the second flux ring, the coil being configured to be energized to electromagnetically polarize the flux of the plurality of first flux protrusions relative to the second set of multiple flux protrusions.

[0024] According to another additional or alternative aspect of this disclosure, an electric motor includes: a rotor that rotates about a motor axis; and a stator that includes at least one phase. Each phase includes: a first flux ring including a first set of a plurality of flux protrusions circumferentially arranged around the motor axis, each of the first set of flux protrusions being at least partially formed by each of the first set of a plurality of laminates; a second flux ring including a second set of a plurality of flux protrusions circumferentially arranged around the motor axis, each of the second set of flux protrusions being at least partially formed by each of the second set of a plurality of laminates; a plurality of axial return elements, each axial return element being formed by a corresponding stack of the first set of a plurality of laminate stacks, the first set of a plurality of laminate stacks being unevenly arranged around the motor axis, each axial return element bridging between the first flux ring and the second flux ring; and a coil coaxial with the motor axis and located directly between the first flux ring and the second flux ring, the coil being configured to be energized to electromagnetically polarize the flux of the first set of a plurality of flux protrusions relative to the second set of a plurality of flux protrusions.

[0025] According to another additional or alternative aspect of this disclosure, an electric motor includes: a rotor that rotates about a motor axis; and a stator including at least one phase with an air gap between the rotor and the stator, each phase including: a first group of a plurality of flux protrusions circumferentially arranged about the motor axis; a second group of a plurality of flux protrusions circumferentially arranged about the motor axis; a coil coaxial with the motor axis and axially located between the first group of a plurality of flux protrusions and the second group of a plurality of flux protrusions; and a potting compound that embeds the first group of a plurality of flux protrusions, the second group of a plurality of flux protrusions, and the coil in a continuous matrix of the potting compound, the potting compound forming a first group of a plurality of recesses facing the air gap. Attached Figure Description

[0026] Figure 1 This is a schematic block diagram of a transverse flux electric motor.

[0027] Figure 2A It is an isometric view showing the components of an electric motor in isolation.

[0028] Figure 2B This is an isometric view of the stator of an electric motor.

[0029] Figure 3A This is an exploded view of the phase components of an electric motor.

[0030] Figure 3B It is along Figure 3A The enlarged cross-sectional view taken from line AA shows the electromagnetic flux flowing through the phase assembly.

[0031] Figure 3C It is along Figure 3A An enlarged sectional view taken from line AA in the diagram shows the relationship with... Figure 3B The electromagnetic flux flows in opposite directions as shown.

[0032] Figure 3D This is an enlarged end view showing the magnetic polarity of the components in the rotor section.

[0033] Figure 4A This is an end view of the flux loop in the first axial direction.

[0034] Figure 4B This is an end view of the flux loop in the second axial direction.

[0035] Figure 4C This is an end view of the flux ring in the first axial direction, and the axial return element is also shown.

[0036] Figure 5A It is an isometric view of the phase component.

[0037] Figure 5B yes Figure 5A The image shows an isometric view of the phase assembly with the flux loop removed.

[0038] Figure 5C yes Figure 5A An enlarged isometric view of a portion of the phase assembly shown.

[0039] Figure 5D It is along Figure 5A An enlarged sectional view taken from line DD in the diagram.

[0040] Figure 6A This is the elevation end view of the stator.

[0041] Figure 6B It is along Figure 6A The sectional view taken from line BB in the middle.

[0042] Figure 6C This is a top view of the stator.

[0043] Figure 7A This is an isometric view of the teeth.

[0044] Figure 7B yes Figure 7A Elevation side view of the tooth.

[0045] Figure 7C yes Figure 7A The first elevation end view of the tooth.

[0046] Figure 7D yes Figure 7A A top view of the teeth.

[0047] Figure 7E yes Figure 7A The second elevation end view of the tooth.

[0048] Figure 8 This is an enlarged isometric view of a portion of a flux ring, showing the retainer of the flux protrusion without teeth.

[0049] Figure 9A It is along Figure 5B An enlarged cross-sectional view of the magnetic flux protrusion cut by line 9-9 in the figure.

[0050] Figure 9B yes Figure 9A The diagram shows a anatomical view of the magnetic flux protrusion.

[0051] Figure 10 This is the side view of the component.

[0052] Figure 11A This is a first isometric view of the stator with the potting sleeve in its first state.

[0053] Figure 11B This is a second isometric view of the stator with the potting sleeve in its second state.

[0054] Figure 11C This is a third isometric view of the stator with the potting sleeve in its second state, and the insert is shown.

[0055] Figure 12A This is an enlarged end view showing a portion of the stator with recesses.

[0056] Figure 12B This is a partial side view of the stator showing the recess.

[0057] Figure 13 This is a three-dimensional end view of the stator showing the recess.

[0058] Figure 14A This is an end view of a portion of the flux ring used in an internal rotor motor, and the insert is shown.

[0059] Figure 14B It is similar to Figure 14A The end view shows the flux loop after the potting compound has cured and the insert has been removed.

[0060] Figure 15 This is a schematic diagram of the insert inside the stator of an internal rotor motor. Detailed Implementation

[0061] This invention relates to a transverse flux motor. The motor includes a rotor rotatable about a motor axis and a stator configured to drive the rotation of the rotor. The stator of the transverse flux electric motor includes phase assemblies, such as one, two, three, or more phase assemblies, formed by flux rings and coils axially disposed between opposing flux rings. The flux rings include flux protrusions extending radially relative to the motor axis and toward the rotor. The flux protrusions may include teeth extending axially on the coils. An axial return engages the flux rings of the phase assemblies, contacting each flux ring and disposed on the radial side of the coil opposite to the rotor. The rotor includes permanent magnets and concentrators interposed between the permanent magnets. It should be understood that although the motor is generally discussed as an electric motor, the principles discussed herein also apply to other motors, such as generators.

[0062] Figure 1This is a block diagram of motor 10. Motor 10 includes rotor 12, stator 14, and motor controller 16. Rotor 12 includes rotor body 18 and permanent magnet array 20. Stator 14 includes phase assemblies 22a, 22b, and 22c (collectively referred to herein as "one phase assembly 22" or "multiple phase assemblies 22"). Phase assembly 22a includes flux loops 24a and 24b; coil 26; and axial return element 28. Phase assembly 22b includes flux loops 24c and 24d; coil 26; and axial return element 28. Phase assembly 22c includes flux loops 24e and 24f; coil 26; and axial return element 28. Flux loops 24a-24f are collectively referred to herein as "one flux loop 24" or "multiple flux loops 24".

[0063] The rotor 12 is radially spaced from the stator 14, forming an air gap 30 between them. The motor 10 extends along a motor axis AA, and the rotor 12 is configured to rotate about the motor axis AA. In the illustrated example, the rotor 12 surrounds the stator 14, making the motor 10 an outer rotor. However, it should be understood that some examples of the motor 10 include a stator 14 extending around the rotor 12, making the motor 10 an inner rotor. A permanent magnet array 20 is mounted radially inside the rotor body 18. The permanent magnet array 20 is positioned through the air gap 30 from the stator 14, radially spaced from the stator 14. The permanent magnet array 20 includes a plurality of permanent magnets arranged annularly around the motor axis AA.

[0064] The stator 14 is formed by phase assemblies 22 arranged along the motor axis AA. Each phase assembly 22 includes a pair of flux loops 24 disposed on opposite axial sides of the coil 26 of the phase assembly 22. Flux loops 24a and 24b are paired to form phase assembly 22a and are disposed on opposite axial sides of the coil 26 of the phase assembly 22. Flux loops 24c and 24d are paired to form phase assembly 22b and are disposed on opposite axial sides of the coil 26 of the phase assembly 22b. Flux loops 24e and 24f are paired to form phase assembly 22b and are disposed on opposite axial sides of the coil 26 of the phase assembly 22c.

[0065] In some examples, a portion of each flux loop 24 may extend axially over the coil 26. Thus, a portion of each flux loop 24 may be radially positioned between the coil 26 and the permanent magnet array 20, as discussed in more detail below. The flux loop 24 is formed of a laminate and may include powder metal components. The flux loop 24 may be configured to have a radially oriented laminate texture.

[0066] The laminate can be formed from a material that is easily affected by the polarization of the field generated by coil 26. Such materials are typically ferromagnetic. Ferromagnetic materials can be materials such as iron or iron alloys, for example, steel. More specifically, the laminate can be formed from silicon steel and other options. Ferromagnetic materials can also be ceramics doped or otherwise embedded with ferromagnetic elements.

[0067] For each phase assembly 22, an axial return element 28 is disposed on the radial side of the coil 26 opposite to the permanent magnet array 20. The axial return element 28 extends between and connects the pairs of flux loops 24 in each phase assembly 22. The axial return element 28 is electrically connected to the pairs of flux loops 24. The axial return element 28 may be formed from stacked laminates having a laminate texture oriented axially (e.g., parallel to the motor axis AA).

[0068] Each coil 26 is a winding of wire (typically copper) around the motor axis AA. Therefore, each coil 26 can be a continuous winding of 20, 30, 40, 50, 100, or fewer and more loops of wire around the motor axis. In some embodiments, alternative wire windings are used.

[0069] Controller 16 is electrically or communicatively connected to motor 10 in an operable manner to control the operation of motor 10, thereby controlling the rotational output of motor 10. Controller 16 may have any desired configuration for controlling the operation of motor 10 and may include control circuitry and memory. Controller 16 is configured to store executable code, implement functions, and / or process instructions. Controller 16 is configured to perform any of the functions discussed herein, including controlling the operation of any components referenced herein. Controller 16 may have any suitable configuration for controlling the operation of motor 10, acquiring data, processing data, etc. Controller 16 may include hardware, firmware, and / or stored software. Controller 16 may have any type suitable for operation according to the techniques described herein. Although controller 16 is illustrated as a single unit, it should be understood that controller 16 may be mounted entirely or partially on one or more boards. In some examples, controller 16 may be implemented as multiple discrete circuit sub-components.

[0070] During operation, an alternating current (AC) signal travels through each coil 26. Because the current of the AC signal passing through coil 26 is reversed, the AC signal rapidly builds and dissipates the magnetic field. Flux-concentrating materials (e.g., flux ring 24 and axial return member 28) of each phase assembly 22 wrap around at least three sides of coil 26. Generally, the flux flows along the direction and texture of the laminates because the flux will generally follow the path of highest permeability, and there is significant impedance when the flux jumps from one laminate to another. The laminate texture of flux ring 24 can be radially oriented relative to the motor axis AA, while the laminate texture of axial return member 28 can be axially oriented relative to the motor axis AA. Thus, the flux flows in a U-shaped path around coil 26 and axially toward rotor 12 through axial return member 28 and radially through flux ring 24.

[0071] The AC signal routed through coil 26 is time-synchronized with the rotational position of the permanent magnet array 20 used to drive the rotation of rotor 12, thereby generating a magnetic field through flux loop 24. The corresponding AC signals (e.g., sinusoidal or trapezoidal) transmitted through coil 26 in each phase assembly 22a, 22b, 22c are out of phase relative to each other. In this way, the magnets forming the permanent magnet array 20 have flux peaks acting on them more frequently than synchronizing the sinusoidal AC signals, thus providing a smoother torque profile acting on rotor 12 along motor axis AA. The embodiment of motor 10 discussed has three phases corresponding to the three phase assemblies 22a, 22b, 22c and corresponding coils 26 in these three phase assemblies. Thus, three sinusoidal AC signals are transmitted through coil 26 with an electrical offset of 120 degrees. It should be understood that although motor 10 is generally discussed as an electric motor, it can also be a generator.

[0072] Figure 2A It is an isometric view showing the components of motor 10 in isolation. Figure 2B This is an isometric view of stator 14. We will discuss it together. Figure 2A and Figure 2B The motor 10 includes a rotor 12 and a stator 14. A permanent magnet array 20 of the rotor 12 is shown. The permanent magnet array 20 includes magnets 32 and a concentrator 34. The stator 14 includes phase assemblies 22a, 22b, and 22c. Phase assembly 22a includes flux loops 24a and 24b; a coil 26; and an axial return member 28. Phase assembly 22b includes flux loops 24c and 24d; a coil 26; and an axial return member 28. Phase assembly 22c includes flux loops 24e and 24f; a coil 26; and an axial return member 28. Each flux loop 24a-24f includes a loop body 36, a trunk 40, a branch 42, and a flux protrusion 44. Each flux protrusion 44 includes a retainer 46 and teeth 48.

[0073] The motor 10 includes a stator 14 surrounded by a rotor 12. The stator 14 is configured to drive the rotor 12 to rotate about a motor axis AA. Both the rotor 12 and the stator 14 are arranged coaxially about the motor axis AA. An air gap 30 is radially disposed between the rotor 12 and the stator 14 and similarly has a cylindrical profile coaxial with the motor axis AA. In the example shown, the rotor 12 surrounds the stator 14 such that the rotor 12 rotates circumferentially about the motor axis AA around the stator 14. The motor 10 can therefore be considered an external rotating motor. However, it should be understood that some examples include a rotor 12 located radially inside the stator 14. In such examples, the motor 10 can be considered an internal rotating motor. Whether the rotor 12 is surrounding the stator 14 or within the stator 14, the operating principle of the motor 10 and the structure of the rotor 12 and the stator 14 can be similar. Although the following discussion relates to embodiments where the rotor 12 rotates about the stator 14, it should be understood that these teachings are equally applicable to embodiments where the rotor 12 rotates within the stator 14.

[0074] In the illustrated embodiment, the rotor 12 includes a permanent magnet array 20. The permanent magnet array 20 includes a plurality of magnets 32. The plurality of magnets 32 are arranged in a ring around a motor axis AA. More specifically, the tubular array of the plurality of magnets 32 is coaxial with the motor axis AA. The plurality of magnets 32 are arranged circumferentially around the stator 14 and the motor axis AA.

[0075] Each magnet 32 ​​has a long axis LA, such as Figure 2A As indicated. The long axis LA is axially oriented parallel to the motor axis AA. Each magnet 32 ​​also has a short axis SA, as... Figure 2A As indicated. The short axis SA is orthogonal to the long axis and oriented tangentially to a circle centered on the motor axis AA. Each magnet 32 ​​has a permanent pole oriented circumferentially—the north pole N (…). Figure 3D (as shown) and Antarctica S ( Figure 3D (As shown in the diagram). More specifically, each magnet 32 ​​has a north pole at one end of the short axis SA and a south pole at the opposite end of the short axis SA. Each of the north and south poles extends along the length of the long axis LA such that the north and south poles are separated by an axial interface along the long axis LA. The north and south poles of each magnet 32 ​​are not axially oriented in the manner that magnets are typically divided into north and south poles at opposite ends of the long axis. Each magnet 32 ​​is continuous between phase assemblies 22a-22c such that each magnet 32 ​​extends straight parallel to the motor axis AA and is positioned to magnetically interact with each phase assembly 22.

[0076] In the illustrated embodiment, the plurality of magnets 32 are arranged in a ring around the stator 14, but as previously mentioned, for the example of an inner rotor of the motor 10, the plurality of magnets 32 may be arranged radially in a ring within the stator 14. The stator 14 and the rotor 12 are magnetically mated to drive the rotor 12 to rotate about the stator 14 and the motor axis AA. The stator 14 may not include any permanent magnets, but instead includes electromagnets that generate a magnetic field when the coil 26 is energized, as further described herein. Similarly, the rotor 12 may include only permanent magnets and not any electromagnets.

[0077] The rotor 12 also includes a plurality of concentrators 34. The plurality of concentrators 34 are staggered with the plurality of magnets 32 such that the magnets 32 and concentrators 34 alternate, and each magnet 32 ​​is held in place by a concentrator 34 and each concentrator 34 is held in place by a magnet 32. In this way, none of the magnets 32 are physically in contact with each other, but are still physically secured by the plurality of concentrators 34. The plurality of concentrators 34 are axially oriented such that the long axis of each concentrator 34 is parallel to the motor axis AA. The long axis of each concentrator 34 is parallel to the long axis of each magnet 32. Each concentrator 34 may be formed of stacked laminates. The long axis of each laminate is oriented parallel to the motor axis AA. Thus, the texture of the stacked laminates is axially oriented.

[0078] The stator 14 includes an array of phase assemblies 22a-22c. Phase assemblies 22a-22c are arranged along the motor axis AA. Each phase assembly 22 is formed by a pair of magnetic flux rings 24. Phase assembly 22a is formed by pairs of magnetic flux rings 24a and 24b. Phase assembly 22b is formed by pairs of magnetic flux rings 24c and 24d. Phase assembly 22c is formed by pairs of magnetic flux rings 24e and 24f. Coils 26 are axially sandwiched between the pairs of magnetic flux rings 24 of each phase assembly 22. The plurality of coils 26 do not overlap each other along the motor axis AA. There is an axial gap along the motor axis AA between each coil 26 arranged along the motor axis AA. Phase assemblies 22a-22c do not overlap each other along the motor axis AA. The magnetic flux rings 24 of each phase assembly 22a-22c do not overlap or contact each other. For example, the flux loops 24a and 24b of phase assembly 22a do not overlap with flux loops 24c and 24d or flux loops 24e and 24f along the motor axis AA. Unlike the flux loops 24 of different phase assemblies 22, the flux loops 24 within each phase assembly 22 (e.g., flux loops 24a and 24b of phase assembly 22a) do overlap axially along the motor axis AA. Specifically, the teeth 48 of the pairs of flux loops 24 forming each phase assembly 22 overlap axially along the motor axis AA.

[0079] Each of the phase components 22a, 22b, and 22c may be structurally and functionally identical, differing only in that the signals transmitted via coil 26 are out of phase relative to each other. In some examples, each flux ring 24 may have a common base configuration, as discussed in more detail below. For example, flux ring 24a of phase component 22a may have the same operating geometry as flux ring 24b of phase component 22a. Pairs of flux rings in flux rings 24 are assembled such that the first flux ring in flux ring 24 (e.g., flux ring 24a) has teeth 48 projecting in a first axial direction AD1, and the second flux ring in flux ring 24 (e.g., flux ring 24b) has teeth 48 extending in a second axial direction AD2 opposite to the first axial direction AD1. The teeth 48 of the first flux ring 24 extend into the circumferential gap between the teeth 48 of the second flux ring 24. The teeth 48 of the second flux ring 24 extend into the circumferential gap between the teeth 48 of the second flux ring 24.

[0080] Each flux ring 24a-24f includes an array 38a-38f of annular flux protrusions 44, each formed by a flux protrusion 44 of the flux ring 24. The arrays 38a-38f can be collectively referred to as "one array 38 of flux protrusions" or "a plurality of arrays 38 of flux protrusions". The plurality of flux rings 24a-24f are arranged along the motor axis AA. Each flux ring 24a-24f is coaxial with the motor axis AA. The laminate forming each flux ring 24 also forms a portion of the flux protrusion 44 of the flux ring 24. For example, a retainer 46 may be formed from the laminate. The flux protrusion 44 in this embodiment also includes powder metal ends formed by teeth 48. However, it should be understood that in various other examples, the laminate may completely form the flux protrusion 44.

[0081] The annular flux protrusion arrays 38a-38f are coaxial with the motor axis AA. Each flux protrusion array 38 is formed by flux protrusions 44 of its flux ring 24. Each flux protrusion 44 protrudes toward the rotor 12. For example, each flux protrusion 44 may extend radially toward the rotor 12 relative to (orthogonal to) the motor axis AA. In this embodiment, each flux protrusion 44 is a structure that narrows toward the rotor 12 in order to concentrate the focused flux to a limited portion of the rotor 12. In some embodiments, the flux protrusions 44 may not narrow toward the rotor 12, but may still concentrate flux toward the rotor 12. In the illustrated example, because the rotor 12 is positioned radially outward from the stator 14, the flux protrusions 44 protrude outward from the motor axis AA. However, in an alternative inner rotor embodiment, the flux protrusions 44 protrude inward toward such a rotor 12 and toward the motor axis AA. The flux protrusions 44 of the stator 14 are arranged to have a tubular profile. More specifically, the flux protrusions 44 are arranged in a ring around the motor axis AA and axially along the motor axis AA. In this way, the stator 14 includes a plurality of circular flux protrusion arrays 38a-38f.

[0082] Figures 2A to 2B Six circular flux protrusion arrays 38a-38f are shown, arranged along the motor axis AA. Each circular flux protrusion array 38a-38f is coaxial with the motor axis AA.

[0083] The circular flux protrusion arrays 38a-38f can each be formed as part of the plurality of flux rings 24a-24f. Each flux ring 24 supports all the flux protrusions 44 of its corresponding circular flux protrusion array 38. Each flux ring 24 can be a continuous laminate or formed from a plurality of laminates arranged around a motor axis AA. In this example, each flux ring 24a-24f includes a ring body 36, a trunk 40 extending radially relative to the ring body 36, and branches 42 supported by the trunk 40. The flux protrusions 44 extend from the branches 42. Whether assembled from discrete laminates that each support a plurality of flux protrusions, but not all of the flux protrusions 44, of the circular flux protrusion array 38, or formed from a continuous laminate of all the flux protrusions 44 supporting the circular flux protrusion array 38, the circular flux protrusion array 38 is supported by a flux ring 24, which allows flux to flow between circumferentially adjacent flux protrusions 44 of the phase assembly 22.

[0084] In the example shown, each flux protrusion array 38 extends radially from the ring body 36 of its flux ring 24. Each ring body 36 is coaxial with the motor axis AA. In the example shown, a trunk 40 extends radially from the ring body 36. Because the rotor 12 is an outer rotor in the example shown, each trunk 40 extends radially outward from the ring body 36. Each branch 42 is supported by an associated trunk 40. In the example shown, each branch 42 protrudes from one of the associated trunks 40 toward the rotor. Each branch 42 extends circumferentially relative to the trunk 40. In the example shown, each branch 42 extends along a first circumferential direction CD1 (in... Figure 2A In the view, it is clockwise) and the second circumferential direction CD2 (in Figure 2A (In the view, it extends counterclockwise). Each branch supports multiple flux protrusions in flux protrusion 44. Flux protrusion 44 extends relative to branch 42 and toward rotor 12.

[0085] However, it should be understood that in some examples, the flux loops 24a-24f do not include the loop body 36 and / or the trunk 40. In this case, the branches 42 are directly connected to and / or supported by other structures, such as by epoxy resin bonding. In some examples, multiple laminates are assembled to form each circular flux protrusion array 38a-38f, such as multiple arcuate sections assembled together.

[0086] In the illustrated example, each flux protrusion 44 ends with powdered metal teeth 48, which may be ideal in some embodiments because the powdered metal component does not lack the oriented texture of a laminate. However, it should be understood that various embodiments are not limited thereto, and each flux protrusion 44 may not include powdered metal components. Each flux protrusion 44 may be formed partially or completely by a laminate. For example, each flux protrusion 44 may be formed by a laminate that forms other portions of the flux ring 24 (and in some examples, the ring body 36).

[0087] As shown in the figure, multiple circumferentially adjacent portions of the flux protrusions 44 of a single flux loop 24 are formed by a single laminate. Each flux protrusion 44 may be continuous with a branch 42, trunk 40, and / or ring body 36 of the flux loop 24. In this way, the flux protrusions 44, branches 42, trunk 40, and / or ring body 36 may be formed by a single laminate or multiple laminates. In the illustrated embodiment, the laminates form the flux loop 24 as continuous pieces. The flux protrusions 44, branches 42, trunk 40, and / or ring body 36 may have a laminate texture extending radially (e.g., orthogonally) relative to the motor axis AA. In some examples, this laminate texture may be radially oriented only.

[0088] Each phase assembly 22 includes a pair of circular flux protrusion arrays 38 formed by flux protrusion arrays 38 of paired flux rings 24 of the phase assembly 22. For example, flux protrusion arrays 38a, 38b form the paired flux protrusion arrays of phase assembly 22a. As discussed in more detail below, the paired flux protrusion arrays 38a-38f of each phase assembly 22a-22c are connected by axial return members 28. Each set of paired flux protrusion arrays 38 is formed by flux protrusions 44 of the paired flux rings 24 (e.g., the paired flux protrusion arrays 38a, 38b of phase assembly 22a are formed by flux protrusions 44 of flux ring 24a and flux protrusions 44 of flux ring 24b).

[0089] The pairs of flux loops 24a-24f in each phase assembly 22 are connected by axial return members 28. Each axial return member 28 is a stack of laminates with an axial (i.e., parallel to the motor axis AA) texture orientation. In some examples, the laminates are stacked circumferentially relative to the axis AA. In some examples, the laminate texture of the axial return member 28 may be axial only. The axial return member 28 conducts electromagnetic flux between each pair of flux loops 24 forming the phase assembly 22. Similarly, the axial return member 28 conducts electromagnetic flux between each pair of circular flux protrusion arrays 38 of the phase assembly 22. Similarly, the axial return member 28 conducts electromagnetic flux between axially adjacent branches 42 in each set of paired flux loops 24. For example, the axial return member 28 conducts electromagnetic flux between axially adjacent branches 42 of flux loops 24a and 24b for phase assembly 22a. As further explained herein, the flux protrusions 44 of the paired flux rings in flux rings 24a-24f and the paired circular flux protrusion arrays in circular flux protrusion arrays 38a-38f form multiple flux loops through stator 14, which magnetically acts on magnet 32 ​​of rotor 12 to cause rotor 12 to rotate relative to stator 14.

[0090] Coils 26 are axially arranged between pairs of flux loops in flux ring 24. Each coil 26 is a winding of wire (typically copper) around the motor axis AA. Each coil 26 may be a continuous winding of 20, 30, 40, 50, 100, or fewer or more loops around the motor axis. These loops together form a hoop of coil 26. In some embodiments, a tape may replace the wire winding. In the illustrated example, each coil 26 has two terminating coil connectors 50a, 50b representing the ends of the circuitry of each coil 26. The coil connectors 50a, 50b of coil 26 may be formed by the wires forming the windings of coil 26 and are configured to allow AC signals to travel through coil 26, which may be connected to controller 16 ( Figure 1 Electrical connection. For each phase assembly 22, coil connectors 50a, 50b extend between circumferentially adjacent axial return members in the axial return member 28 and between the axially spaced ring bodies 36 of the paired flux loops 24 of the phase assembly 22.

[0091] Because the teeth 48 of the flux protrusions 44 project axially, each coil 26 radially overlaps with the flux protrusions 44 of the associated phase assembly 22. However, it should be understood that in some examples, the flux protrusions 44 do not project axially, and instead project only radially (towards or away from the motor axis AA). Each coil 26 is axially located directly between the pairs of flux rings 24 of its phase assembly 22. Each coil 26 of each phase assembly 22 is completely located between the pairs of flux rings 24 of that phase assembly 22. The coils 26 of phase assembly 22a are axially disposed between flux rings 24a, 24b; the coils 26 of phase assembly 22b are axially disposed between flux rings 24c, 24d; and the coils 26 of phase assembly 22c are axially disposed between flux rings 24e, 24f.

[0092] In the illustrated example, each flux protrusion 44 is formed by a retainer 46, which is formed of a laminate, and the tooth 48 is formed of powder metal. The retainer 46 holds the tooth 48 to the flux ring 24. As discussed in more detail below, the tooth 48 can be press-fitted to the retainer 46, and the retainer 46 can clamp the tooth 48 to the flux ring 24 to form the flux protrusion 44. The tooth 48 protrudes axially from the retainer 46 and relative to the laminated portion of the flux ring 24. The tooth 48 protrudes axially from its flux ring 24 to the other flux rings 24 forming the phase assembly 22. A portion of each tooth 48 is radially disposed between the associated coil 26 and the permanent magnet array 20 of the rotor 12.

[0093] Figure 3A This is an exploded view of phase component 22a. Figure 3B and Figure 3C This demonstrates how a magnetic flux loop can be formed by the paired magnetic flux protrusions 44a and 44b. Figure 3D Detailed views of the paired flux protrusions 44a, 44b of the phase assembly 22a, which interacts with the concentrator 34 and magnet 32 ​​of rotor 12, are shown. These will be discussed together. Figures 3A to 3D Phase assembly 22a includes flux rings 24a and 24b; a coil 26; and an axial return member 28. Flux ring 24a includes a ring body 36a, a main trunk 40a, a branch 42a, and a flux protrusion 44a. Flux ring 24b includes a ring body 36b, a main trunk 40b, a branch 42b, and a flux protrusion 44b. Flux protrusions 44a and 44b respectively include retaining members 46a and 46b and teeth 48a and 48b.

[0094] Magnetic flux ring 24a is oriented along the motor axis AA in a first axial direction AD1, such that tooth 48a protrudes axially in the first axial direction AD1. Magnetic flux ring 24b is oriented in the opposite direction to magnetic flux ring 24a. Magnetic flux ring 24b is oriented along the motor axis AA in a second axial direction AD2, such that tooth 48b protrudes axially in the second axial direction AD2. Coil 26 is located directly between the paired magnetic flux rings 24a and 24b of phase assembly 22a. Coil 26 is axially disposed between magnetic flux rings 24a and 24b. More specifically, coil 26 is located directly between the opposing branches 42a and 42b of the paired magnetic flux rings 24a and 24b. More specifically, coil 26 is located directly between portions of the paired flux protrusions 44a, 44b of the paired flux protrusion arrays 38a, 38b (e.g., directly between flux protrusions 44a of flux ring 24a and flux protrusions 44a of flux ring 24b). Coil 26 radially overlaps with axial return member 28. In this particular example, since each flux protrusion 44a, 44b has axially extending teeth 48a, 48b respectively, coil 26 is radially sandwiched between axial return member 28 and flux protrusions 44a, 44b.

[0095] An axial return member 28 extends between and is electrically connected to the paired flux rings 24a and 24b. The axial return member 28 extends into an opening in each flux ring 24a and 24b. The axial return member 28 can directly contact the side of the branches 42a and 42b opposite to the flux protrusions 44a and 44b. The axial return member 28 is configured to conduct electromagnetic flux between the flux rings 24a and 24b. Similarly, the axial return member 28 conducts electromagnetic flux between the array of circular flux protrusions 38a and 38b of the phase assembly 22a. Likewise, the axial return member 28 conducts electromagnetic flux between axially adjacent branches 42a and 42b of the paired flux rings 24a and 24b.

[0096] The axial return member 28 extends into an opening radially defined in the flux ring 24a between the branch 42a and the ring body 36a. This opening is circumferentially defined between the main trunks 40a. The axial return member 28 further extends into a pair of openings radially defined in the flux ring 24b between the branch 42b and the ring body 36b. This opening is circumferentially defined between the main trunks 40b.

[0097] The flux-paired flux protrusions 44 refer to the closest pair of corresponding flux protrusions 44 in the opposing circular flux protrusion arrays 38 of the phase assembly 22 (e.g., the flux protrusions 44 of flux protrusion arrays 38a and 38b are flux-paired, and the flux protrusion arrays 38c and 38d are flux-paired). Figure 2B The flux protrusions 44 are paired, and the flux protrusion arrays 38e and 38f ( Figure 2B The flux protrusions 44a and 44b are paired. Figure 3B and Figure 3C The flux protrusions 44 are highlighted as flux pairs, but these are examples, and all flux protrusions 44 can similarly be flux pairs on the circular flux protrusion arrays 38a, 38b. Each flux protrusion 44a is part of a flux loop similar to its corresponding flux protrusion 44b. The flux protrusions 44a, 44b, which are paired with each other, are generally axially paired with adjacent flux protrusions 44 of the same circular flux protrusion array 38, rather than circumferentially paired. This is because all flux protrusions 44 of the first flux protrusion array in the paired array 38 (e.g., the first flux protrusion array in arrays 38a and 38b) will have the same polarity at any given time, while all flux protrusions 44 of the opposing circular flux protrusion arrays 38 of the same phase component 22 (e.g., the other flux protrusion array in arrays 38a and 38b) will have opposite polarities at any given time. More specifically, each flux protrusion 44 is flux-paired with the nearest flux protrusion 44 of the circular flux protrusion array 38 on the other side of the coil 26. Figure 3B and Figure 3C As shown, a magnetic flux loop is formed by pairs of flux protrusions 44a and 44b, such that flux protrusions 44a and 44b are polarized as the north and south poles, respectively. All flux protrusions 44 of phase assembly 22 are simultaneously polarized.

[0098] Magnetic flux is generated by coil 26. Specifically, an AC signal travels through coil 26, and because the current of the AC signal passing through coil 26 is reversed, coil 26 rapidly builds and dissipates the magnetic field. As shown, the flux-concentrating material of flux rings 24a and 24b and axial return member 28 surrounds at least three sides of coil 26. In the example shown, the flux-paired flux protrusions 44a and 44b; the flux-concentrating material of flux rings 24a and 24b; and the axial return member 28 completely surround coil 26.

[0099] exist Figure 3B and Figure 3CThe image shows the laminate texture of the flux-concentrating material. Generally, the flux flows along the direction of the laminate and the texture because the flux will generally follow the path of highest permeability, and there is significant impedance when jumping from one laminate to another. The laminate texture of branches 42a, 42b (including flux protrusions 44a, 44b other than powder metal teeth 48a, 48b) is radially oriented, while the laminate texture of the axial return member 28 is axially oriented. The laminate sheets of flux rings 24a, 24b can thus be arranged orthogonally to the laminate sheets of the axial return member 28.

[0100] In addition to the teeth 48 formed of powder metal, the flux loops 24a and 24b are formed of stacked laminates. The flux loop 24a can be formed of stacked laminates, wherein each layer covers the entire flux loop 24a. For example, the stacked laminates can form complete coils 36a, each trunk 40a, each branch 42a, and each retainer 46a. Thus, the retainer 46a on one radial side of the flux loop 24a can be formed of the same layer as the retainer 46a provided on the opposite radial side of the flux loop 24a. The flux loop 24b can be formed similarly to the flux loop 24a by axially stacked and radially extending continuous laminates. Thus, the phase assembly 22a can include two consecutive stacks of radially extending laminates (forming flux loops 24a and 24b), and can include multiple consecutive stacks of axially extending laminates (forming axial return members 28).

[0101] In the example shown, the laminates forming the flux loops 24a and 24b are axially stacked and have a radial texture. The stacked laminates of the flux loops 24a and 24b can be oriented in a plane orthogonal to the motor axis AA. The laminate forming each flux loop 24a and 24b can be continuous for the entire portion of the flux loop 24a and 24b formed by the laminate. For example, the flux loop 24a can be formed by a continuous laminate from the coil 36a to the trunk 40a to the branch 42a and to the retainer 46a. The laminate stack forming the flux loop 24 can include at least ten layers of sheets.

[0102] The laminates of the axial return member 28 can be stacked tangentially to a circle centered on the motor axis AA and have an axial texture. Each laminate of the axial return member 28 can contact each laminate of a directly adjacent branch 42a, 42b. In some examples, the axial return member 28 can directly contact each laminate of the flux ring 24. In some examples, each axial return member 28 directly contacts each laminate of the phase assembly 22a, such that each axial return member 28 directly contacts each laminate of the flux ring 24a and directly contacts each laminate of the flux ring 24b. The laminate stack forming the axial return member 28 can include at least ten layers of sheets.

[0103] The magnetic flux flows axially through the axial return member 28 in a U-shape around the coil 26 and toward the rotor 12, and radially through the branches 42a, 42b and the magnetic flux protrusions 44a, 44b. Figure 2A and Figure 3A ). Figure 3B and Figure 3C Indicates the inversion of the AC signal (the signal in...) Figure 3B In the first state and in Figure 3C (In the second state) and how to switch the poles of the paired magnetic flux protrusions 44a and 44b.

[0104] The flux protrusions 44a and 44b are not axially aligned; instead, each of the paired flux protrusions 44a and 44b is offset circumferentially. Thus, the flux loop travels at least a finite circumferential distance between the paired flux protrusions 44a and 44b. Therefore, the accumulated flux loop, including multiple paired flux protrusions 44a and 44b, can flow circumferentially through the flux protrusions 44a and 44b and the axial return member 28 in a spiral pattern. The AC signal through the coil 26 rapidly changes the current direction, and thereby rapidly changes the north and south poles of the paired flux protrusions 44a and 44b.

[0105] In the illustrated example, flux protrusions 44a and 44b are aligned with concentrator 122. The laminate of concentrator 122 does not have inherent polarization, but due to the fixed position of concentrator 34 between the poles of magnet 32, it exhibits the same effective permanent polarization as the adjacent poles of magnet 32, as indicated. Magnets 32 are arranged such that for adjacent magnets in magnet 32, the same poles are oriented toward each other circumferentially. A single concentrator 34 thus alternates between two north poles or two south poles and exhibits the polarization of these poles. Concentrator 34 exhibits alternating north and south pole polarization on opposite sides of each magnet 32. As indicated, each magnet 32 ​​is polarized along its short axis SA ( Figure 2A The magnet 32 ​​and the concentrator 34 are permanently polarized to the north and south poles. The staggered arrangement of the magnet 32 ​​and the concentrator 34 produces alternating regions of opposite polarization of the poles of the concentrator 34 and the magnet 32.

[0106] Concentrator 34 routes magnetic flux from magnet 32 ​​toward stator 14. The flux loop is a complete loop spanning the air gap 30 between stator 14 and rotor 12. Magnetic flux from rotor 12 (specifically magnet 32) and from coil 26 (via flux protrusion 44) interact in the air gap 30, and the resulting flux shear drives the rotation of rotor 12. The flux of this motor 10 has a transverse orientation to the motor axis AA. This differs from the radial flux orientation of conventional AC motors and DC brushless motors.

[0107] Due to the positional changes of the permanent magnet array 20 (e.g., circumferential positional changes of magnets 32 and concentrator 34 around axis AA) and the rotation of the rotor 12, as well as the polarization changes of the flux protrusions 44a and 44b caused by the changes in the AC signal through coil 26, the magnetic flux generated by the stator 14 and acting on the rotor 12 is constantly changing. Thus, the AC signal routed through coil 26 is synchronized in time with the approach and departure of the concentrator 34 from the flux protrusions 44a and 44b to generate a magnetic field through the flux protrusions 44a and 44b, thereby simultaneously pushing and pulling the magnets 32 of the rotor 12 to provide a force that rotates the rotor 12. More specifically, during the aligned approach and departure, the NN and SS interfaces repel each other, while the NS interface attracts each other.

[0108] Continue to refer to Figures 2A to 3D Through each phase component 22a, phase component 22b ( Figure 2B ) and phase component 22c ( Figure 2B The corresponding AC signals (e.g., sinusoidal or trapezoidal) transmitted by the coil 26 are out of phase with each other. In this way, compared to synchronizing sinusoidal AC signals, magnet 32 ​​(along the long axis LA of the magnet) transmits signals that are out of phase with each other. Figure 2B The length of the magnet more frequently has flux peaks acting on the magnet. The out-of-phase signal provides a smooth torque profile acting on the rotor 12 along the axis of rotation of the rotor 12. Figures 1 to 2B The illustrated embodiment of the motor 10 has three phases corresponding to three phase components 22a, 22b, and 22c, and coils 26 in the phase components, wherein three sinusoidal AC signals are transmitted via the coils 26 with an electrical offset of 120 degrees. If there are two phase components 22 and two coils 26, the two sinusoidal AC signals will be electrically offset by 180 degrees, or for a set of four phase components 22 and four coils 26, the electrical offset is 90 degrees.

[0109] Because the magnet 32 ​​is elongated and radially overlaps with the multiple phase components 22 and thus with the multiple coils 26, each magnet 32 ​​is electromagnetically acted upon by the multiple coils 26. More specifically, in the three-phase embodiment shown, each magnet 32 ​​can be electromagnetically acted upon simultaneously by three coils 26 along the length of the magnet 32. Depending on the specific motor 10 ( Figure 1 and Figure 2AThe number of phases of the motor 10 determines whether each magnet 32 ​​can be acted by more or fewer coils 26. Thus, multiple different coils 26 electromagnetically act on each magnet 32. Furthermore, each magnet 32 ​​can be electromagnetically acted by only three coils 26 (or only two coils 26 in a two-phase motor embodiment, or only four coils 26 in a four-phase motor embodiment, etc.). This differs from conventional AC induction motors, where each magnet interacts with all the coils in a conventional circumferential coil array around the rotor's axis of rotation. Each magnet 32 ​​can be acted simultaneously by each coil 26 of the motor 10, unlike conventional AC induction motors where each magnet is acted by individual coils in a stepwise manner.

[0110] Traditional AC induction motors use multiple discrete coils arranged circumferentially around the rotor's axis of rotation. Each coil represents a potential pole acting on a magnet. In traditional AC induction motors, these discrete coils arranged circumferentially around the axis of rotation are out of phase with respect to each other. The number of poles in such a motor is limited by the ability to assemble discrete coils circumferentially around the axis of rotation within the motor. The coil windings can be made smaller, and the stator diameter can be made larger to accommodate more coils to support more poles, but this increases the size, weight, and cost of the motor and still has its limitations. Power can also be increased when the rotor rotates at relatively high speeds, allowing more coil-magnet to pass through per unit time. However, this would require the motor to operate at relatively high speeds, which may be undesirable depending on the application.

[0111] The motor 10 according to this disclosure differs from conventional AC motors and DC brushless motors. Motor 10 contains a relatively small number of coils 26, with only three coils in the example discussed. Unlike conventional AC motors and DC brushless motors, the coils 26 are formed by loops extending completely around the axis of rotation of the rotor 12, such as... Figure 3A As shown. The plurality of rings together form the coil ferrule of coil 26. The axis of rotation of rotor 12 extends through each ring (e.g., the center of each ring). Each coil 26 is annular, and the rings of each coil 26 are identically annular, and the circular planar profile of the coil 26 and the rings is orthogonal to the motor axis AA. The conductors of each coil 26 form a single coil ferrule, which has a plurality of rings that overlap and contact each other to form a single coil ferrule assembly.

[0112] Coil 26 does not include any loops through which the motor shaft AA does not extend to generate the magnetic flux that rotates the rotor 12. Instead of adding a new coil for each pole in a conventional AC induction motor, branches 42 and axial return members 28 surrounding a single coil 26 guide the magnetic flux to the plurality of flux protrusions 44, which cross pairs of branches 42a, 42b to create multiple poles from a single coil 26. In the example shown, flux rings 24a, 24b each include thirty flux protrusions 44a, 44b. Thus, for each phase assembly 22, one coil 26 supports thirty poles; however, fewer and more poles can be created depending on the number of flux protrusions 44 in the circular flux protrusion array 38. Thus, activating one coil 26 activates multiple poles, whereas in some conventional AC motors and DC brushless motors, activating one coil activates one pole. Motor 10 includes a plurality of coils 26 arranged as part of a plurality of phase assemblies 22 along and around the rotational axis of rotor 12. The plurality of phase components 22 providing the plurality of coils 26 double the number of poles, which can act simultaneously on the permanent magnet array 20 and thereby drive the rotation of the rotor 12.

[0113] Figure 4A This is the first end view of the flux ring 24. Figure 4B From and Figure 4A The second end view of the flux loop 24 taken from the opposite side of the shown flux loop 24. Figure 4C This is a first end view of the flux loop 24, which also shows the axial return element 28. These will be discussed together. Figures 4A to 4C The flux ring 24 includes a ring body 36, a trunk 40, branches 42, flux protrusions 44, gaps 52, and return openings 54a, 54b (collectively referred to herein as "one return opening 54" or "a plurality of return openings 54"), positioners 64a-64c (collectively referred to herein as "one positioner 64" or "a plurality of positioners 64"), and circumferential gaps 66a, 66b (collectively referred to herein as "one circumferential gap 66" or "a plurality of circumferential gaps 66"). Each branch 42 includes a return mating surface 58. Each flux protrusion 44 includes a retainer 46 and teeth 48. This disclosure refers to a separation distance, which, unless otherwise specified, can be a linear distance between two structures, a circumferential distance between two structures (e.g., measured in arcs around a motor axis), or an angular distance between two structures (e.g., measured in radial angles relative to a motor axis).

[0114] A ring body 36 is arranged annularly around the motor axis AA. A trunk 40 extends radially from the ring body 36. In the example shown, because the flux ring 24 is used for an external rotor motor (e.g., motor 10), Figure 1 and Figure 2ATherefore, the main trunk 40 extends radially outward. However, it should be understood that in other examples, the main trunk 40 may extend radially inward toward axis AA. Each branch 42 connects to the associated main trunk 40. In the example shown, each branch 42 extends relative to the associated main trunk 40 in each circumferential direction CD1 and CD2. The branches 42 are asymmetrically arranged about axis AA. Flux protrusions 44 extend radially and axially relative to each branch 42. In the example shown, each branch 42 supports five individual flux protrusions 44, but it should be understood that each branch 42 may support more than five or fewer than five flux protrusions 44. Each branch 42 and associated flux protrusion 44 can be considered to form a flux unit extending radially relative to the ring body 36. In the example shown, the flux ring 24 includes six flux units. The flux units are asymmetrically arranged about axis AA.

[0115] Each flux protrusion 44 is formed by a retainer 46 and a tooth 48, the retainer 46 extending from the branch 42, the tooth 48 being supported by and extending from the retainer 46. The retainer 46 may be formed from a laminate forming the branch 42. The retainer 46 extends radially from the branch 42 and is configured to support an associated tooth 48 extending axially from the retainer 46. The retainer 46 may extend between two axial ends of the flux ring 24. A spacing gap 52 is circumferentially disposed between adjacent flux protrusions in the flux protrusions 44. The width of each flux protrusion 44 is such that it faces the air gap 30 ( Figure 1 and Figure 2A The magnetic flux protrusion 44 narrows in the radial direction. The magnetic flux protrusion 44 is asymmetrically arranged about the axis AA.

[0116] The circumferential line CL1 forms a circle centered on the axis AA. The circumferential line CL1 is positioned at the valley of each gap 52 between adjacent flux protrusions in the flux protrusion 44. The circumferential line CL1 is also positioned at the junction between the branch 42 and the flux protrusion 44. The branch 42 may be formed from a single laminate, while the flux protrusion 44 may be formed from a laminate (e.g., a retainer 46) and powder metal (e.g., teeth 48). The laminate portion of the flux protrusion 44 may be integrally formed with the laminate of the branch 42.

[0117] Return openings 54a and 54b are radially defined between branch 42 and ring body 36. Return openings 54a and 54b form a ring with axial openings circumferentially disposed around motor axis AA. Return mating surfaces 58 of branch 42 partially define each return opening 54a and 54b. Return mating surfaces 58 of branch 42 can extend tangentially to a circle centered on motor axis AA. Each return mating surface 58 of each branch 42 is configured to be tangential to the same circle centered on motor axis AA. Thus, radial lines extending from motor axis AA can be orthogonal to the planar return mating surfaces 58. In the illustrated example, each branch 42 partially defines return opening 54a and partially defines return opening 54b. Thus, each branch 42 includes a pair of return mating surfaces 58. Return openings 54a and 54b are configured to receive axial return members 28. The axial return member 28 directly contacts the return member mating surface 58 to facilitate magnetic flux transfer between the return member mating surfaces and form a magnetic flux loop.

[0118] Return openings 54a and 54b, also referred to as return slots, are circumferentially defined between adjacent main sections 40. In the illustrated example, each main section 40 defines one end of return opening 54a and one end of return opening 54b. The main sections 40 are arranged asymmetrically about the motor axis AA such that the configuration of return opening 54a differs from that of return opening 54b. The spacing between adjacent main sections 40 varies, resulting in variable-sized return openings 54a and 54b.

[0119] Return openings 54a and 54b are alternately arranged circumferentially around axis AA. Thus, each return opening 54a is circumferentially positioned between two return openings 54b, and each return opening 54b is circumferentially positioned between two return openings 54a. Return openings 54a and 54b together define an annular ring around motor axis AA, within which the axial return member 28 is disposed. Return openings 54a and 54b are asymmetrically arranged about motor axis AA. In the illustrated example, return opening 54a has a different configuration than return opening 54b. Return opening 54a extends further around motor axis AA than return opening 54b. Thus, return opening 54a has a larger circumferential width than return opening 54b. The circumferential width of the return opening 54 is the length taken along the circumference of a circle centered on axis AA. The circumferential width of each return opening 54 can be obtained between the main trunks 40 that circumferentially clamp the return openings 54.

[0120] Return member openings 54a are asymmetrically arranged about the motor axis AA, such that they are unevenly spaced about the motor axis AA. Similarly, return member openings 54b are asymmetrically arranged about the motor axis AA, such that they are unevenly spaced about the motor axis AA. Each of the return member openings 54a and 54b is configured to support a pair of axial return members 28. A trunk 40 defines the circumferential end of each return member opening 54a and 54b.

[0121] Each return opening 54a has two receiving portions 56a, 56b, each of which is partially defined by a different branch of a branch 42 of the return opening 54a. More specifically, each receiving portion 56a, 56b is partially defined by a return mating surface 58 of the branch 42. Each receiving portion 56a, 56b is configured to receive an axial return 28. An angle α is formed between the return mating surfaces 58 of adjacent branches defining the return opening 54a in the branch 42. Thus, the receiving portions 56a, 56b are laterally positioned relative to each other. Angle α is an obtuse angle.

[0122] Each return opening 54b has two receiving portions 56c, 56d, each of which is partially defined by a different branch of the branch 42 of the return opening 54b. More specifically, each receiving portion 56c, 56d is partially defined by a return mating surface 58 of the branch 42. Each receiving portion 56c, 56d is configured to receive an axial return 28. An angle β is formed between the return mating surfaces 58 of adjacent branches defining the return opening 54b in the branch 42. Thus, the receiving portions 56c, 56d are transverse relative to each other. Angle β is an obtuse angle. Angle β can be the same as angle α.

[0123] Each axial return member 28 may have a configuration common to the other axial return members 28. The return member mating surface 58 has a plane oriented toward the motor axis AA and is configured to mate with the axial return member 28. Each return member mating surface 58 is arranged orthogonally to a radial line extending from the axis AA. The axial return member 28 directly contacts the return member mating surface 58 to form a magnetic flux loop. Each return member mating surface 58 may have the same configuration. For example, each return member mating surface 58 may have the same width between the main trunk 40 of the branch 42 of the return member mating surface 58 and the end of the return member mating surface 58 that is circumferentially opposite to the main trunk 40 around the axis AA. Thus, each receiving portion 56a-56d may have the same width.

[0124] Circumferential gaps 66a and 66b are provided between adjacent flux units in the flux unit. Circumferential gap 66 is provided at opposite circumferential ends of each branch 42. The circumferential gaps 66 are arranged alternately around the motor axis AA. In the illustrated example, each branch 42 partially defines a circumferential gap 66a at a first circumferential end of the branch 42 and partially defines a circumferential gap 66b at an opposite second circumferential end of the branch 42. The branches 42 may have different configurations to position the circumferential gaps 66a and 66b; return openings 54a and 54b; and flux protrusions 44 for assembling the flux rings 24 into the phase assembly 22, as discussed in more detail below. In the illustrated example, the branches 42 are formed in two configurations, which are combined to form a tooth segment pair. The first configuration of the branch 42 has branch ends 60a and 60b, and the second configuration of the branch has branch ends 60c and 60d. Each tooth segment pair is circumferentially positioned between circumferential gaps 66a and includes circumferential gaps 66b between paired branches 42. The tooth segment pair can be rotationally symmetric about axis AA. Thus, the tooth segment pair can exhibit triple rotational symmetry about axis AA.

[0125] Branch ends 60a and 60c partially define a circumferential gap 66a. As branch end 60a extends away from the engagement between flux protrusion 44 and branch 42 and toward return opening 54a, it extends circumferentially toward the corresponding trunk 40 supporting branch 42. Similarly, as branch end 60c extends away from the engagement between flux protrusion 44 and branch 42 and toward return opening 54a, it extends circumferentially toward the corresponding trunk 40 supporting branch 42.

[0126] The circumferential gap 66a has a first radial portion that narrows along its radial extent toward the motor axis AA. Each circumferential gap 66a has a second radial portion that widens along its radial extent toward the motor axis AA. The first radial portion is defined between flux protrusions 44 on the circumferential side of the circumferential gap 66a. The second radial portion is defined between adjacent branch ends 60a, 60c. The circumferential gap 66a can thus be considered to have an hourglass configuration. The circumferential width of the circumferential gap 66a at any radial position along each circumferential gap 66a is greater than the circumferential width of the gap 52 or the circumferential gap 66b at the same radial distance from the axis AA.

[0127] Branch ends 60b and 60d partially define a circumferential gap 66b. As branch end 60b extends away from the engagement between flux protrusion 44 and branch 42 and toward return opening 54b, it may extend circumferentially toward the corresponding trunk 40 supporting branch 42. In some examples, branch end 60b extends only radially so that it does not tilt toward the trunk 40 of branch 42. As branch end 60d extends away from the engagement between flux protrusion 44 and branch 42 and toward return opening 54b, it extends circumferentially toward the corresponding trunk 40 supporting branch 42.

[0128] The circumferential clearance 66b may have a first radial portion that extends radially away from the air gap 30 along the radial extent of the circumferential clearance 66b. Figure 1 and Figure 2A The circumferential gap 66b narrows towards the motor axis AA. Each circumferential gap 66b includes a second radial portion that widens towards the motor axis AA along the radial extent of the circumferential gap 66b. The first radial portion is defined between the flux protrusions 44 on the circumferential side of the circumferential gap 66b. The second radial portion is defined between adjacent branch ends 60b, 60d. The circumferential gap 66b can be considered to have an hourglass configuration.

[0129] The branch ends 60a-60d are circumferentially inclined to position the axial return member 28 and the flux protrusion 44 at desired circumferential positions around the motor axis AA. The axial return member 28 extends between and contacts adjacent flux rings in the flux ring 24 forming the phase assembly 22. A pair of axial return members 28 are disposed in each return member opening 54a, and a pair of axial return members 28 are disposed in each return member opening 54b. The axial return member 28 includes a planar surface that contacts the planar surface of the return member mating surface 58 of the branch 42. The circumferential gap 66a is wider than the circumferential gap 66b, such that the axial return members 28 in the return member opening 54a are offset from each other by a greater distance than the axial return members 28 in the return member opening 54b. The circumferential spacing between the axial return members 28 in the return member opening 54a provides the electrical connector with a path for radial extension between these axial return members 28 and into the coil 26 (best see...). Figure 3A ).

[0130] The width of each circumferential gap 66a at each radial position relative to the motor axis AA is greater than the width of the circumferential gap 66b at the same radial position. The separation distance between adjacent branches 42 and the flux protrusions 44 defining the circumferential gap 66a is greater than the separation distance between branches 42 and the flux protrusions 44 defining the circumferential gap 66b. As discussed in more detail below, the circumferential gap 66a is the coil connector 50b (best seen in...). Figure 5C and Figure 5D An opening is provided to extend from the radial side coil 26 opposite to the axial return member 28, around the coil 26, and through the wire gap 67 between these axial return members 28, to facilitate electrical connection to an AC power source.

[0131] A circumferential clearance 66b is provided radially outward at the joint between two laterally arranged axial return members 28. The circumferential clearance 66b separates adjacent branches 42 such that those adjacent branches 42 are circumferentially spaced apart from each other. The circumferential clearance 66b removes material from the flux ring 24, thereby providing a lighter motor 10. The circumferential clearances 66a, 66b between adjacent branches 42 suppress the formation of eddy currents. The circumferential clearances 66a, 66b also prevent the formation of a continuous circuit around the motor axis AA. The circumferential clearance 66b is narrower in the circumferential direction than the circumferential clearance 66a. Thus, the clearance 69 between the axial return members 28 associated with the circumferential clearance 66b is narrower than the clearance 67 between the axial return members 28 associated with the circumferential clearance 66a. The dimensional variation and asymmetrical spacing of the axial return members 28 around the axis AA facilitate a larger axial return member 28 in a compact arrangement, thereby providing an efficient and compact motor. The axial return members 28 are arranged asymmetrically about the motor axis AA, and in the example shown, there are three different separation distances between adjacent axial return members 28. The axial return members 28 associated with the same tree-shaped member including the trunk 40 and associated branches 42 are spaced apart by the trunk 40 of that tree-shaped member, thus forming a gap of a first size. The axial return members of adjacent tree-shaped members are separated by one of gaps 67, 69, which have different dimensions from each other and different from the size of the gap created by the trunk 40.

[0132] The axial return element 28 is arranged circumferentially and non-uniformly around the motor axis AA. The laminate stacks forming the axial return element 28 are thus arranged circumferentially and non-uniformly around the motor axis AA. The laminate stacks forming the axial return element 28 are arranged circumferentially and non-uniformly around the motor axis AA such that a first pair of adjacent laminate stacks have a first separation distance between them, and a second pair of adjacent laminate stacks have a second separation distance different from the first separation distance. The laminate stacks forming the axial return element 28 are arranged circumferentially and non-uniformly around the motor axis AA such that a third pair of adjacent laminate stacks have a third separation distance different from the first and second separation distances.

[0133] The flux loops 24 are operably aligned around the flip axis BB such that the flux loops 24 can form two flux loops of the phase assembly 22. The flip axis BB divides the flux loops 24 into a first lateral portion 62a and a second lateral portion 62b. The flux loops 24 are operably aligned around the flip axis BB such that the phase assembly 22 can be formed from flux loops 24 having the same basic configuration. For example, Figure 3A Phase component 22a in Figure 3A The flux loop 24a and Figure 3A The two flux rings 24a and 24b have the same basic configuration. If the two flux rings 24a and 24b are oriented in the same axial direction, the flux rings 24a and 24b will be axially aligned.

[0134] The flux rings 24 are operably aligned about the flip axis BB to facilitate the formation of the phase assembly 22. The flux rings 24 are configured such that a single flux ring 24 can be used to form half of each phase of the phase assembly 22. Each flux ring 24 has a facing side oriented toward the coil 26 of the phase assembly 22. Each flux ring 24 has a distant side oriented away from the coil 26 of the phase assembly 22. Laminates forming each flux ring 24 are axially stacked between the facing side and the distant side. The coil 26 is thus positioned between the facing sides. The facing sides are oriented toward each other, while the distant sides are oriented away from each other. Teeth 48 overhang on the facing side such that the coil is located in a toroidal chamber defined by the facing side of the flux ring 24, the teeth 48 of the flux ring 24, and the axial return member 28.

[0135] For example, the first flux ring 24 is oriented such that its teeth 48 extend in a first axial direction relative to the motor axis AA, and the second flux ring 24 is oriented such that its teeth 48 extend in the opposite second axial direction. The second flux ring 24 rotates about the flip axis BB to a second orientation different from the first orientation of the first flux ring 24. When the flux rings 24 are in different orientations, the return openings 54 of each flux ring 24 are axially aligned, while the flux protrusions 44 of each flux ring 24 are axially misaligned. When the two flux rings 24 are in opposite orientations, the return openings 54a of the first flux ring 24 of the phase assembly 22 are axially aligned with the return openings 54a of the second flux ring 24 of the phase assembly 22 to facilitate the installation of the axial return member 28. The return openings 54b of the paired flux rings 24 are similarly aligned. Because the main shaft 40 and the return piece mating surface 58 partially define the return piece opening 54, the main shaft 40 and the return piece mating surface 58 are axially aligned. This alignment of the return piece mating surfaces 58 facilitates the axial electrical connection of the return piece 28 to the paired flux loops 24.

[0136] The aligned return opening 54 facilitates the installation of the axial return member 28. In some examples, the return opening 54 provided on the first lateral portion 62a of the flux ring 24 is a mirror image of the return opening 54 formed on the second lateral portion 62b of the flux ring 24 about the flip axis BB. In the example shown, one of the return openings 54a is self-aligned about the axis BB, and one of the return openings 54b is self-aligned about the axis BB.

[0137] Unlike the return opening 54, the flux protrusions 44 are axially misaligned between the opposing flux rings 24 forming the phase assembly 22. The flux protrusions 44 of the first flux ring 24 are circumferentially offset from the flux protrusions 44 of the second flux ring 24 to form a pair of flux protrusions 44.

[0138] The positions of the return opening 54 and the flux protrusion 44 on the first flux ring 24 of the phase assembly 22 are flipped mirror images of the positions of the return opening 54 and the flux protrusion 44 on the second flux ring 24 of the phase assembly 22. The positions associated with the first flux ring 24 are flipped mirror images of the positions associated with the second flux ring 24, such that the position of the flux protrusion 44 of the first flux ring 24 relative to the facing side of the first flux ring 24 is the same as the position of the flux protrusion 44 of the second flux ring 24 relative to the remote side of the second flux ring 24. The positions associated with the first flux ring 24 are flipped mirror images of the positions associated with the second flux ring 24, such that the position of the return opening 54 of the first flux ring 24 relative to the facing side of the first flux ring 24 is the same as the position of the return opening 54 relative to both the facing side and the remote side of the second flux ring 24. The position associated with the first flux ring 24 is a flipped mirror image of the position associated with the second flux ring 24, such that if the first flux ring 24 and the second flux ring 24 are axially aligned, and the first faces of each flux ring in the first flux ring and the second flux ring 24 face the same axial direction, and the flux protrusion 44 of the first flux ring 24 is axially aligned with the flux protrusion 44 of the second flux ring 24, then the return opening 54 of the first flux ring 24 is axially aligned with the return opening 54 of the second flux ring 24.

[0139] In the example shown, the return opening 54 is designed as openings O1-O6. Return openings O1, O3, and O5 are formed by return opening 54a. Return opening O1 is configured to be operatively aligned with itself around the flip axis BB. When assembling phase assembly 22, the receiving portion 56a of return opening O1 in the first flux ring 24 is aligned with the receiving portion 56b of return opening O1 in the opposite second flux ring 24. Thus, a single axial return member 28 extends through the receiving portion 56a of opening O1 in the first flux ring 24 and through the receiving portion 56b of opening O1 in the second flux ring 24. Return opening O3 is aligned with return opening O5 around axis BB such that return openings O3 and O5 are axially aligned in the flux rings 24 of phase assembly 22. Thus, axial return member 28 can extend through return opening O3 of the first flux ring 24 and through opening O5 of the second flux ring 24.

[0140] Return member openings O2, O4, and O6 are formed by return member opening 54b. Return member opening O4 is rotatably aligned relative to itself about axis BB. When assembling phase assembly 22, the receiving portion 56a of return member opening O4 in the first flux ring 24 is aligned with the receiving portion 56b of return member opening O4 in the opposite second flux ring 24. Thus, a single axial return member 28 can extend through the receiving portion 56a of opening O4 in the first flux ring 24 and through the receiving portion 56b of opening O4 in the second flux ring 24. Return member openings O2 and O6 are operably aligned about axis BB such that return member openings O2 and O6 are axially aligned in the flux rings 24 of phase assembly 22. Thus, the axial return member 28 can extend through the return member opening O2 of the first flux ring 24 and through the opening O6 of the second flux ring 24.

[0141] Although the return openings 54a, 54b of each lateral portion 62a, 62b are rotatably aligned about axis BB, the flux protrusions 44 are rotatably misaligned about axis BB. The subset of flux protrusions 44 provided on the first lateral portion 62a is not a mirror image of the flux protrusions 44 on the second lateral portion 62b. The gaps (e.g., with one of the spacing gaps 52 or circumferential gaps 66a, 66b) between the flux protrusions 44 on the first lateral portion 62a of the flux ring 24 and adjacent flux protrusions 44 on the second lateral portion 62b are axially aligned. The gaps between the flux protrusions 44 on the second lateral portion 62b of the flux ring 24 and adjacent flux protrusions 44 on the first lateral portion 62a are axially aligned.

[0142] Each flux ring 24 is therefore partially mirrored about the flip axis BB. The radial portion of the flux ring 24 between the motor axis AA and the return mating surface 58 of the branch 42, including the return mating surface 58 (e.g., ring body 36, trunk 40, return opening 54, and return mating surface 58), is mirrored about the axis BB. Conversely, the return mating surface 58 of the flux ring 24 at the branch 42 is mirrored with respect to the air gap 30 ( Figure 1 and Figure 2A The radial portions between the components (e.g., branch 42, flux protrusion 44, gap 52, circumferential gaps 66a, 66b) are not mirror images of the axis BB, but are misaligned around the axis BB.

[0143] In the example shown, the positioner 64 extends radially inward from the ring body 36. The positioner 64 facilitates the assembly of two flux loops in the flux ring 24 into a phase assembly 22. The positioner 64 also facilitates the assembly of these phase assemblies 22 together to form a stator, such as stator 14 (best see...). Figure 2B and Figures 6A to 6C In the example shown, the flux loop 24 includes three phases corresponding to the motor 10. Figure 1 and Figure 2A The flux loop 24 may include three positioners 64a, 64b, and 64c. However, it should be understood that the flux loop 24 may include any desired number of positioners 64 for aligning the flux loop 24 to assemble it into the phase assembly 22 and / or the stator 14.

[0144] Positioner 64 is formed as a protrusion extending from ring body 36. In the illustrated example, positioner 64 extends radially from ring body 36 toward motor axis AA. Positioner 64 thus extends radially away from air gap 30. Although positioner 64 is shown as a positive alignment feature such that positioner 64 is formed of material extending from flux ring 24, it should be understood that positioner 64 can be formed in any desired manner. For example, positioner 64 can be formed as a negative alignment feature, for example by notching, grooves, or other material removal.

[0145] In the example shown, locators 64a, 64b, and 64c have different configurations to facilitate visual recognition of each locator 64a, 64b, and 64c. Locator 64a is formed as a tab. Locator 64b is formed as a tab with notches. Locator 64c is formed as a tab with multiple notches. However, it should be understood that locators 64a-64c can be formed in any desired manner.

[0146] Positioner 64a is positioned on the flip axis BB and is mirror-image of the flip axis BB. Thus, in the example shown, axis BB bisects positioner 64a. Positioners 64b and 64c are circumferentially offset relative to positioner 64a about motor axis AA. Positioner 64b can be located at the same axial position along axis BB as positioner 64c, such that the positions of positioners 64b and 64c are mirror-images of axis BB.

[0147] Positioner 64a is spaced apart from positioner 64b by a first offset about the motor axis AA, positioner 64a is spaced apart from positioner 64c by a second offset about the motor axis AA, and positioner 64b is spaced apart from positioner 64c by a third offset about the motor axis AA. The positions of positioners 64a-64c are not rotationally symmetrical about the motor axis AA. In some examples, the first offset is the same as the second offset, while the third offset is different from the first and second offsets. In one example, the first and second offsets are less than 120 degrees, while the third offset is greater than 120 degrees. The asymmetrical offsets between positioners 64 facilitate the axial alignment of phase assembly 22 along axis AA to form stator 14, as discussed in more detail below.

[0148] The flux ring 24 is configured to facilitate a large overall width for the axial return member 28, while also providing a location for the coil connector 50b to extend radially inward from the coil 26. The flux ring 24 includes components asymmetrically arranged about the motor axis AA to facilitate operative alignment around the axis BB and the desired positioning of the axial return member 28 and the flux protrusion 44. The flux protrusion 44 and associated teeth 48 need to be located at certain circumferential positions to form flux pairs with the associated flux rings 24 in the phase assembly 22. However, the axial return members 28 are not so constrained. The spacing between the axial return members 28 is generally free, as long as a planar interface is formed between the axial return members 28 and each flux ring 24 of the phase assembly 22.

[0149] The circumferential gap 66b, which is narrower than the circumferential gap 66a, provides a smaller overall size flux ring 24 without sacrificing the size of the axial return member 28. For example, if each circumferential gap 66 were constructed as circumferential gap 66a, the flux ring 24 would need to have a larger diameter and therefore include more material to support the same size axial return member 28 as shown, thus increasing the weight and size of the motor 10.

[0150] In the example shown, flux loop 24 comprises a set of three circumferential gaps 66a. As discussed in more detail below, flux loop 24 can be used to form each flux loop 24a-24f of stator 14. Figure 2B , Figures 6A to 6C Each circumferential gap 66a provides a location for the coil connector 50b to extend radially inward around its coil 26 and toward the motor axis AA. Each of the three individual circumferential gaps 66a is configured to provide a location through which the coil connector 50b of each of the three phase assemblies 22 of the three-phase motor extends.

[0151] The return openings 54 are asymmetrically spaced about the motor axis AA, so that the axial return members 28 are asymmetrically arranged about the motor axis AA. The asymmetrical spacing of the axial return members 28 creates a gap 67 between the axial return members 28 within the return openings 54a, thereby allowing the coil connectors 50a, 50b to extend radially inward between the axial return members 28 to the core of the stator 14. The trunks 40 are asymmetrical about the motor axis AA to provide different dimensions for the return openings 54a, 54b. The trunks 40 are circumferentially non-uniformly arranged around the motor axis AA, such that a first pair of adjacent trunks 40 has a first separation distance between them, and a second pair of adjacent trunks 40 has a second separation distance different from the first separation distance. In some examples, the trunks 40 are circumferentially non-uniformly arranged around the motor axis AA, such that a third pair of adjacent trunks 40 has a third separation distance different from the first and second separation distances.

[0152] Branches 42 are asymmetrically spaced around the motor axis AA. The branches 42 are arranged circumferentially and unevenly around the motor axis AA such that a first pair of adjacent branches 42 or groups of branches 42 have a first separation distance between them, and a second pair of adjacent branches 42 or groups of branches 42 have a second separation distance between them, which is different from the first separation distance. In some examples, the branches 42 are arranged circumferentially and unevenly around the motor axis AA such that a third pair of adjacent branches 42 or groups of branches 42 have a third separation distance between them, which is different from the first and second separation distances.

[0153] The asymmetrical spacing of branches 42 positions the return mating surfaces 58 of the opposing flux rings 24 of the phase assembly 22 in a suitable location to form a planar interface with the axial return member 28. The axial return member 28 mates with the planar mating surfaces 58 on each flux ring 24 of the phase assembly 22. Thus, the axial return member 28 is keyed to the return member opening 54, thereby ensuring proper alignment between the flux rings 24. The asymmetrical spacing of branches 42 also properly positions the flux protrusions 44 in each flux ring 24 of the phase assembly 22 relative to each other during operation. The flux protrusions 44 are asymmetrically spaced about the motor axis AA. The asymmetrical spacing of the flux protrusions 44 facilitates rotation about the axis BB, so that the flux protrusions 44 are axially misaligned on the paired flux rings 24 forming the phase assembly 22.

[0154] The terminal flux protrusion 44 of each branch 42 may extend circumferentially relative to the return mating surface 58 of the branch 42 to which it extends. The terminal flux protrusions 44 are those flux protrusions 44 that are adjacent to and partially define one of the circumferential gaps 66a, 66b. The flux protrusions 44 are configured such that the flux protrusion 44 furthest along each branch 42 in the circumferential direction CD1 extends circumferentially outward relative to the return mating surface 58 of that branch 42. The first circumferential direction CD1 is in... Figure 4A In the view, it is counterclockwise, and Figure 4B In the view, it is clockwise. The circumferential protrusion of the terminal flux protrusion 44 relative to the branch 42 positions the flux protrusion 44 for operatively rotating about axis BB and forming a pair of flux protrusions in the flux protrusion 44. In the example shown, the flux protrusion 44, which defines a circumferential gap 66a and extends radially relative to the branch end 60a, extends the furthest circumferentially relative to the associated return mating surface 58.

[0155] Radial line R1 extends from the motor axis AA through the engagement portion between the branch end 60a and the return member mating surface 58. Radial line R1 extends through the terminal flux protrusion 44, which is furthest in the circumferential direction CD1 and partially defines the circumferential gap 66a. Radial line R1 is circumferentially disposed between the teeth 48 of the flux protrusion 44 and the remaining teeth 48 of the flux protrusion 44 of the branch 42. Radial line R1 may extend partially through the teeth 48. The divided portion of the flux protrusion 44 (i.e., the portion extending in the circumferential direction CD1 relative to radial line R1) may include up to the entire tooth 48. In various examples, the divided portion of the flux protrusion 44 may include at least 95% or more of the volume of the tooth 48 of the flux protrusion 44 and / or at least 95% or more of the area of ​​the axial end 74a of the tooth 48 of the flux protrusion 44.

[0156] A radial line R2 extending from the motor axis AA through the engagement between the branch end 60d and the return member mating surface 58 extends through the terminal flux protrusion in the flux protrusion 44, which is furthest in the circumferential direction CD1 and partially defines the circumferential gap 66b. The radial line R2 is circumferentially disposed between the teeth 48 of the flux protrusion 44 and the remaining teeth 48 of the flux protrusion 44 of the branch 42. The radial line R2 may extend partially through the teeth 48. In some examples, the divided portion of the flux protrusion 44 (i.e., the portion extending in the circumferential direction CD1 relative to the radial line R2) may not include the portion with teeth 48. The divided portion of the flux protrusion 44 may include up to 1%, 2%, 5% or more of the volume of the teeth 48 of the flux protrusion 44 and / or up to 1%, 2%, 5% or more of the area of ​​the axial end 74a of the teeth 48 of the flux protrusion 44.

[0157] Radial line R3 extends through the center of the main trunk 40 supporting branches 42 with branch ends 60c and 60d. Radial line R4 extends through the center of the main trunk 40 supporting branches 42 with branch ends 60a and 60b. The main trunk 40 may be positioned at the midpoint of the base of each branch 42 such that each return mating surface 58 extends the same distance away from the main trunk 40. The main trunk 40 may thus bisect the base of each branch 42. Flux protrusions 44 are circumferentially offset on the branch 42 relative to radial lines R3 and R4 such that radial lines R3 and R4 do not extend through the radial centerline of the middle flux protrusion of the flux protrusion 44 on the branch 42. The set of flux protrusions 44 of each branch 42 is thus circumferentially offset from the main trunk 40 supporting the branch 42. In the example shown, the flux protrusion 44 on the branch 42 with branch ends 60c, 60d is offset by a smaller degree than the flux protrusion 44 on the branch 42 with base ends 60a, 60b. This circumferential offset of the flux protrusion 44 facilitates the positioning of the return openings 54a, 54b and the flux protrusion 44 for operative flipping around the flip axis BB.

[0158] To form phase assembly 22, a first flux ring 24 and a second flux ring 24 are disposed opposite each other. The first and second flux rings 24 are positioned coaxially with the motor axis AA. Each flux ring 24 has the same basic configuration, which defines the radial and circumferential positions of the return opening 54 and the flux protrusion 44 of each flux ring 24. Therefore, the flux rings 24 can be considered to have the same operating geometry.

[0159] The first flux loop 24 is located at a first position on the motor axis AA, and the second flux loop 24 is located at a position on the motor axis AA, which has a flip orientation relative to the first position with respect to the flip axis BB. Positioners 64a of the first flux loop 24 and 64a of the second flux loop 24 are axially aligned to properly position the two flux loops 24 relative to each other. Thus, the flip axis BB of the first flux loop 24 is set parallel to and in a common plane with the flip axis BB of the second flux loop 24 of the phase assembly 22. With positioners 64a axially aligned, positioners 64b of the first flux loop 24 and 64c of the second flux loop 24 are axially aligned, and positioners 64c of the first flux loop 24 and 64b of the second flux loop 24 are axially aligned. With the locator 64a aligned, the teeth 48 of the first flux ring 24 extend into the circumferential space between the teeth 48 of the second flux ring 24, and the teeth 48 of the second flux ring 24 extend into the circumferential space between the teeth 48 of the first flux ring 24.

[0160] The asymmetrical spacing of the positioners 64 around the motor axis AA facilitates proper alignment and provides error prevention. If positioner 64a of the first flux loop 24 is axially aligned with any one of the positioners 64b or 64c of the second flux loop 24, the other positioners in the positioners 64 will be axially misaligned. Axial misalignment between pairs of positioners 64 will identify the paired flux loops 24 as misaligned. The asymmetrical spacing between positioners 64a, 64b, and 64c also facilitates the assembly of phase assemblies 22 formed by identical configurations of flux loops 24 into the stator 14, as discussed in more detail below.

[0161] Coil 26 is positioned between the first flux ring 24 and the second flux ring 24 such that the facing side of each flux ring faces the coil 26. The flux protrusion 44 of the first flux ring 24 is circumferentially offset relative to the flux protrusion 44 of the second flux ring 24. The return member opening 54 of each flux ring 24 is axially aligned. The positions of the return member opening 54 and the flux protrusion 44 of the first flux ring 24 relative to the facing side of the first flux ring 24 are the same as the positions of the return member opening 54 and the flux protrusion 44 relative to the far side of the second flux ring 24. An axial return member 28 is inserted into the return member opening 54 of the flux ring 24 such that the axial return member 28 bridges between the flux rings 24 and is arranged around the motor axis AA.

[0162] The flux ring 24 offers significant advantages. The return opening 54 is asymmetrical about axis AA, but symmetrical about the flip axis BB. This asymmetrical spacing around axis AA provides mounting positions for the axial return members 28 and facilitates the formation of a gap 67 between the axial return members 28, thereby providing positions for coil connectors 50a, 50b to extend between these axial return members 28 without reducing their size. Maintaining a larger size for the axial return members 28 facilitates efficient motor operation in a compact arrangement. The flux protrusion 44 is asymmetrical about motor axis AA and not rotationally symmetrical about the flip axis BB. This asymmetry of the flux protrusion 44 facilitates the dimensional settings of the circumferential gaps 66a, 66b, and the proper positioning of the flux protrusions 44 relative to each other in the opposing flux rings 24 of the phase assembly 22. The flux rings 24 are operably aligned about the flip axis BB so that a single base configuration of the flux ring 24 can be used to form two flux rings 24 of the phase assembly 22. Furthermore, the flux ring 24 can be rotatably positioned around the motor axis AA to form each phase assembly 22 of the stator 14. This configuration reduces the number of parts and allows each flux ring 24 to be formed using a single part, thus simplifying manufacturing and assembly. Only a single configuration of flux ring 24 needs to be manufactured to produce each flux ring in the phase assembly 22 and the stator 14.

[0163] Figure 5A This is an isometric view of phase component 22a. Figure 5B This is an isometric view of phase component 22a with the flux ring 24a removed. Figure 5C This is an enlarged isometric view of a portion of phase component 22a. Figure 5D It is along Figure 5A An enlarged sectional view taken from line DD in the diagram. This will be discussed together. Figures 5A to 5D Phase assembly 22a includes flux rings 24a and 24b; coil 26; and axial return member 28. Flux ring 24a includes a ring body 36a, a trunk 40a, a branch 42a, and a flux protrusion 44a. Flux ring 24b includes a ring body 36b, a trunk 40b, a branch 42b, and a flux protrusion 44b. Each flux protrusion 44a and 44b includes a retainer 46a and 46b, and teeth 48a and 48b, respectively. Coil connectors 50a and 50b of coil 26 are shown.

[0164] Magnetic flux rings 24a and 24b are arranged annularly around the motor axis AA. A coil 26 is axially disposed between the magnetic flux rings 24a and 24b. More specifically, the coil 26 is axially disposed between a branch 42 of magnetic flux ring 24a and a branch 42 of magnetic flux ring 24b. The coil 26 is also radially disposed between portions of the teeth 48a and 48b of each magnetic flux ring 24a and 24b and an axial return member 28. The axial return member 28 is axially oriented relative to the motor axis AA and is disposed on the radial side of the coil 26 opposite to the teeth 48a and 48b. The axial return member 28 extends into the return member opening 54 of the magnetic flux ring formed in each of the magnetic flux rings 24a and 24b, and directly contacts the branches 42a and 42b at a flat interface.

[0165] Magnetic flux ring 24a is in a first orientation, wherein teeth 48a are oriented along a first axial direction AD1, and magnetic flux ring 24b is in a second orientation, wherein teeth 48b are oriented along a second axial direction AD2 opposite to the first axial direction AD1. Magnetic flux ring 24 has the same configuration as magnetic flux ring 24b, except that magnetic flux ring 24a is oriented around a flipping axis BB orthogonal to the motor axis AA. Figure 4A and Figure 4B Rotation. Neither flux rings 24a nor 24b are rotationally symmetrical about an axis orthogonal to the motor axis AA. Unlike flux rings 24a and 24b, phase assembly 22a is rotationally symmetrical about an axis orthogonal to the motor axis AA. More specifically, phase assembly 22a has double rotational symmetry about an axis orthogonal to the motor axis AA, which is coplanar with the flip axis BB and axially positioned between flux rings 24a and 24b.

[0166] Magnetic flux rings 24a and 24b are not mirror images of each other, but are operatively aligned such that, with magnetic flux ring 24a in a first orientation and magnetic flux ring 24b in a second orientation, the return openings 54a and 54b of magnetic flux ring 24a are axially and circumferentially aligned with the return openings 54a and 54b of magnetic flux ring 24b, respectively. The teeth 48a of magnetic flux ring 24a and the teeth 48b of magnetic flux ring 24b are axially misaligned to form a magnetic flux loop between pairs of teeth 48a and 48b in each of the magnetic flux rings 24a and 24b. The teeth 48a of magnetic flux ring 24a are inserted in a ring-like manner between the teeth 48b of magnetic flux ring 24b around axis AA.

[0167] Coil connectors 50a and 50b extend from and provide electrical connection to coil 26. Coil connectors 50a and 50b may be the terminals of wires wound around the motor axis AA to form coils. Because motor 10 is an external rotor motor, each of the coil connectors 50a and 50b extends radially inward toward the motor axis AA.

[0168] Coil connector 50a extends radially inward from coil 26. Coil connector 50a extends into the phase assembly 22 between adjacent axial return members 28 in return member opening 54a. As discussed above, the return member opening 54a is sized to circumferentially space the axial return members 28 within it, and provides a gap 67 for coil connectors 50a and 50b to extend between the axial return members 28. Because coil connector 50a extends radially inward from coil 26a, it can extend directly radially inward from coil 26 into the phase assembly 22 without axially protruding relative to the axial side of coil 26.

[0169] Unlike coil connector 50a, coil connector 50b extends radially outward from coil 26 into the interior of phase assembly 22. Coil connector 50b must project axially relative to coil 26, passing over the axial side of coil 26 and surrounding coil 26 into the interior of phase assembly 22. Each of coil connectors 50a and 50b extends through the axial gap between ring body 36a and ring body 36b.

[0170] The circumferential gap 66a between adjacent branches in the branches 42 of the flux ring 24a facilitates the routing of the coil connector 50b into the interior of the phase assembly 22. The spacing of the defining circumferential gap 66a between the branches 42 provides the coil connector 50b with a position that projects axially relative to the coil 26 and extends radially inward and around the axial surface of the coil 26.

[0171] like Figure 5D As best viewed, the coil connector 50b protrudes axially relative to the coil 26 and the axis AA, such that the coil connector 50b partially overlaps the flux ring 24a circumferentially relative to the axis AA. The coil connector 50b can extend axially to be circumferentially disposed between the flux protrusions 44a defining a circumferential gap 66a, and can be circumferentially disposed between the branches 42a defining the circumferential gap 66a. The circumferential gap 66a provides a radially inwardly extending position for the coil connector 50b without removing the laminate material from the flux ring 24. The coil connector 50b traveling through the circumferential gap 66a facilitates a compact arrangement of the motor 10 because the length of each phase assembly 22 along the motor axis AA does not need to be increased to provide space for routing the coil connector 50b between the flux ring 24a and the coil 26. The coil connector 50b is not axially disposed between the branches 42 or flux protrusions 44 of the flux rings 24a and 24b, but rather circumferentially disposed between the laminated portions of the flux ring 24a.

[0172] Flux rings 24a and 24b offer significant advantages. A circumferential gap 66a is formed between adjacent branches in branch 42 and positions the axial return member 28 to facilitate routing of coil connectors 50a and 50b to the core of phase assembly 22a. The axial return member 28 is asymmetrical about axis AA to provide a gap 67 extending between the coil connectors 50a and 50b. The circumferential gap 66a provides space for coil connector 50b to extend axially relative to coil 26 along axis AA for routing around the axial surface of coil 26. Coil connector 50b extends axially to partially overlap the flux ring 24a circumferentially. However, the length of phase assembly 22a and the axial length of the laminate forming flux rings 24a and 24b relative to axis AA are unaffected. The circumferential gap 66a allows coil connector 50b to extend around the axial side of coil 26 and between adjacent branches 42 defining the circumferential gap 66a. The routing of coil connector 50b through circumferential gap 66a facilitates a compact arrangement of phase assembly 22a and allows flux rings 24a, 24b to be positioned as close as possible to coil 26 along axis AA. Furthermore, circumferential gap 66a facilitates the winding of the wire forming coil 26 along a single circumferential direction, thus providing a single-wound coil 26.

[0173] Figure 6A This is the elevation end view of stator 14. Figure 6B It is along Figure 6A The sectional view taken from line BB in the middle. Figure 6C This is a top view of stator 14. We will discuss it together. Figures 6A to 6C The stator 14 includes phase assembly 22a, phase assembly 22b, and phase assembly 22c. Phase assembly 22a includes flux loops 24a and 24b; coil 26; and axial return member 28. Phase assembly 22b includes flux loops 24c and 24d; coil 26; and axial return member 28. Phase assembly 22c includes flux loops 24e and 24f; coil 26; and axial return member 28.

[0174] The stator 14 is formed from phase assemblies 22a-22c, each phase assembly having a common phase configuration. Phase assembly 22a is disposed at a first axial end of the stator 14, phase assembly 22c is disposed at a second axial end of the stator 14, and phase assembly 22b is axially disposed between phase assemblies 22a and 22c. Phase assemblies 22a-22c are axially stacked along the motor axis AA and are coaxially disposed with the motor axis AA.

[0175] Phase assembly 22a is formed by pairs of flux rings 24a and 24b disposed on opposite axial sides of coil 26. Phase assembly 22a includes an array of axial return members 28 surrounding a circumferential axis AA. The axial return members 28 extend between and contact each flux ring in flux rings 24a and 24b. The axial return members 28 are electrically connected to flux rings 24a and 24b. Phase assembly 22b is formed by pairs of flux rings 24c and 24d disposed on the axial side of coil 26. Phase assembly 22b includes an array of axial return members 28 surrounding a circumferential axis AA. The axial return members 28 extend between and contact each flux ring in flux rings 24c and 24d. The axial return members 28 are electrically connected to flux rings 24c and 24d. Phase assembly 22c is formed by pairs of flux rings 24e and 24f disposed on the axial side of coil 26. Phase assembly 22c includes an array of axial return members 28c surrounding a circumferential axis AA. The axial return members 28c extend between and contact each flux ring in flux rings 24e and 24f. The axial return members 28c are electrically connected to flux rings 24e and 24f.

[0176] As discussed above, a single basic configuration of flux ring 24 can be used to form each flux ring 24 in the phase assembly 22. Each phase assembly 22 formed by such flux ring 24 has the same basic phase configuration. In the example shown, each flux ring in flux rings 24a-24f has the same basic configuration, but around the motor axis AA and / or around their flip axes BB ( Figure 4A and Figure 4B They are offset relative to each other. For example, flux ring 24b flips relative to flux ring 24a on the flipping axis BB, but does not rotate relative to flux ring 24a around axis AA. Flux ring 24c rotates relative to flux ring 24a around motor axis AA. Flux ring 24d flips relative to flux ring 24c on the flipping axis BB, but does not rotate relative to flux ring 24c around motor axis AA. Flux ring 24e rotates relative to both flux rings 24a and 24c around motor axis AA. Flux ring 24f flips relative to flux ring 24e on the flipping axis BB, but does not rotate relative to flux ring 24e around motor axis AA.

[0177] Flux rings 24a-24f have the same basic configuration to align the return opening 54 between pairs of flux rings 24a-24f forming phase assemblies 22a-22c and to misalign the teeth 48. Forming each flux ring 24a-24f with a common basic configuration simplifies manufacturing because only a single component type is needed to form each of the six flux rings 24a-24f of the three-phase stator 14. A single configuration of flux ring 24 can be used to form all six flux rings of the stator 14 by rotating the basic flux ring 24 about the motor axis AA and / or flipping the basic flux ring 24 about the axis BB.

[0178] Each phase assembly 22a-22c thus has the same basic phase configuration. Phase assemblies 22a-22c are stacked axially along the motor axis AA. Phase assemblies 22a-22c are rotated and offset relative to each other about the motor axis AA to appropriately offset phase assemblies 22a-22c to generate electromagnetic flux for driving rotor 12. Phase assemblies 22a-22c are rotated and offset relative to each other about the axis AA to form stator 14. As discussed above, AC signals for the illustrated three-phase stator are provided to each phase assembly 22a-22c with a 120-degree electrical offset. However, phase assemblies 22a-22c are not mechanically offset relative to each other about the motor axis AA by 120 degrees. In the example shown, phase assembly 22a is offset less than 120 degrees relative to phase assembly 22b about the motor axis AA in the circumferential direction CD2. Phase assembly 22c is offset less than 120 degrees relative to phase assembly 22b about the motor axis AA in the circumferential direction CD1. The mechanical offset around the motor axis AA positions the pairs of flux protrusions in the flux protrusions 44 of each phase assembly 22a-22c in the appropriate position relative to each other and generates electromagnetic flux in a timely manner to act on the magnet 32 ​​and drive the rotation of the rotor 12.

[0179] The common components of each phase assembly 22a-22c are offset relative to each other circumferentially around the motor axis AA, so that these components are not axially aligned along the motor axis AA. Figure 6B Ideally, the axial return element 28 of phase assembly 22a is offset about the motor axis AA relative to the axial return elements 28 of both phase assemblies 22b and 22c. Similarly, the axial return element 28 of phase assembly 22b is offset about the motor axis AA relative to the axial return element 28 of phase assembly 22c. Figure 6A As shown, the coil connectors 50a and 50b for each phase assembly 22a-22c extend into the interior of the stator 14 at different circumferential positions around the motor axis AA.

[0180] like Figure 6CIn the optimal configuration, the teeth 48a of the flux ring 24a are axially misaligned with teeth 48b-48f along the motor axis AA, such that a line extending through the circumferential midpoint of tooth 48a and parallel to the motor axis AA does not extend through the circumferential midpoint of any tooth in teeth 48b-48f; tooth 48b is axially misaligned with teeth 48c-48f along the motor axis AA; tooth 48c is axially misaligned with teeth 48d-48f along the motor axis AA; tooth 48d is axially misaligned with teeth 48e and 48f along the motor axis AA; tooth 48d is axially misaligned with tooth 48f along the motor axis AA. Thus, the paired flux protrusions in the flux protrusions 44 of each phase assembly 22 are offset about the motor axis AA relative to the paired flux protrusions in the flux protrusions 44 of the other phase assembly 22. Phase assemblies 22a-22c are mechanically offset about axis AA to facilitate the rotation of rotor 12 by transmitting out-of-phase AC signals through coils 26 of phase assemblies 22a-22c.

[0181] For specific references Figure 6B Positioners 64 are used to align phase components 22a, 22b, and 22c relative to each other to form stator 14. As discussed above, positioners 64a align pairs of flux loops 24a-24f forming each phase component 22a-22c. When positioners 64a are aligned, positioners 64b of the pair of first flux loops 24 (e.g., flux loop 24a for phase component 22a) are aligned with positioners 64c of the pair of second flux loops 24 (e.g., flux loop 24b for phase component 22a), and positioners 64c of the pair of first flux loops 24 are aligned with positioners 64b of the pair of second flux loops.

[0182] In the illustrated example, the positioners 64 are arranged in three axial arrays within the stator 14. One of the arrays is considered the main alignment array, which instructs the phase assemblies 22a, 22b, 22c to be properly aligned along and about the motor axis AA to form the stator 14. This alignment array includes three pairs of positioners 64 axially aligned relative to the motor axis AA. The other two arrays include at least one pair of positioners 64 axially offset from the other positioners 64 in the array relative to the motor axis AA. In the illustrated example, the positioners 64 of the alignment array are arranged axially from flux loop 24a to flux loop 24f in the first axial direction AD1 as positioners 64b, 64c, 64a, 64a, 64c, and 64b.

[0183] Although phase assemblies 22a-22c are discussed as being aligned based on distinct pairs of positioners 64 to form stator 14, it should be understood that phase assemblies 22a-22c can be positioned relative to each other in any desired manner in an operable manner. For example, each phase assembly 22 may include a single positioning feature (e.g., a pair of positioners 64a forming the flux loop 24 of that phase assembly 22) positioned at a desired circumferential position relative to the motor axis AA based on the axial position of the phase assembly 22 in stator 14. During assembly of stator 14, the positioning feature of each phase assembly 22 can be oriented at the desired position to properly position each phase assembly 22 relative to the other phase assemblies 22. For example, a series of three slots may be arranged around the motor axis AA, and the phase assemblies 22 may be oriented by aligning the positioners 64 on each phase assembly 22 with the slots.

[0184] Phase assemblies 22a-22c are configured such that stator 14 is rotationally symmetrical about stator rotation axis CC. Stator rotation axis CC is orthogonal to motor axis AA and is axially positioned between pairs of positioners 64a of phase assemblies 22 (e.g., between flux loops 24c and 24d of phase assembly 22b) along motor axis AA. Axis CC is parallel to both the axes BB of flux loop 24c and BB of flux loop 24d. Axis CC is positioned in the same plane as the plane extending through both the axes BB of flux loop 24c and BB of flux loop 24d. However, phase assemblies 22a and 22c are rotationally offset about motor axis AA relative to flux loops 24c and 24d of phase assembly 22b. Thus, axis CC is oriented transversely to the axes BB of flux loops 24a and 24b and the axes BB of flux loops 24e and 24f. Each flux loop 24a-24f is not rotationally symmetrical about an axis orthogonal to motor axis AA. Unlike flux loop 24, stator 14 is rotationally symmetric about an axis orthogonal to axis AA. More specifically, stator 14 has double rotational symmetry about stator rotation axis CC.

[0185] Stator 14 offers significant advantages. Each phase assembly 22a, 22b, 22c can have the same basic phase configuration. Having phase assemblies 22a, 22b, 22c with the same basic configuration reduces the number of parts and simplifies manufacturing. Only a single configuration of phase assemblies 22 is required to form the three-phase stator 14 shown. Individual flux loops 24a-24f with the same configuration rotate about axis AA and flip about axis BB to form six different orientations of flux loops 24a-24f, thus forming the three-phase stator 14. This allows each of the six different components of stator 14 to be formed using a single basic flux loop configuration, reducing the number of parts and material costs while also simplifying manufacturing. Stator 14 is also rotationally symmetrical about axis CC, simplifying the installation and operation of stator 14.

[0186] Figure 7A This is an isometric view of tooth 48. Figure 7B yes Figure 7A Elevation side view of tooth 48. Figure 7C yes Figure 7A First elevation end view of tooth 48. Figure 7D yes Figure 7A Top view of tooth 48. Figure 7E yes Figure 7A The second elevation end view of tooth 48. This will be discussed together. Figures 7A to 7E The tooth 48 includes a first portion 68, a second portion 70, a clearance surface 72, and axial ends 74a and 74b. The first portion 68 includes a contact surface 76 and clamping surfaces 78a and 78b. The contact surface 76 includes lateral surfaces 80a and 80b and a base surface 82. The second portion 70 includes a contoured portion 84.

[0187] Tooth 48 is a powder metal component comprising compacted metal particles, such as iron particles, having desired magnetic properties. Tooth 48 extends axially between axial end 74a and axial end 74b. Axial end 74a is formed by an axially oriented surface of a first portion 68. Axial end 74a is the distal end of the first portion 68. Axial end 74b is formed by an axially oriented surface of a second portion 70. Axial end 74b is the distal end of the second portion 70.

[0188] The first portion 68 may have a continuous or nearly continuous cross-sectional profile orthogonal to the motor axis AA between the axial end 74a and the engagement between the first portion 68 and the second portion 70. The clearance surface 72 may be configured to create an operatively consistent clearance between the tooth 48 and the magnet 32 ​​of the permanent magnet array 20. In some examples, the clearance surface 72 may be planar. Radial lines extending from the motor axis AA may be orthogonal to the planar clearance surface 72. The portion of the clearance surface 72 formed on the first portion 68 may be rectangular and have a common circumferential width along its axial length relative to the axis AA. The portion of the clearance surface 72 formed on the second portion may be rectangular or may taper to narrow toward the axial end 74b, as discussed in more detail below. Although the clearance surface 72 is described as planar, it should be understood that the clearance surface 72 may have a radius that makes the clearance surface 72 either convex (e.g., for an outer rotor) or concave (e.g., for an inner rotor). The radius of the tooth 48 at the gap surface 72 can be matched with the radius of the radial outer end of the magnetic flux protrusion array 38 on which the tooth 48 is provided.

[0189] The clamping surface 78a extends radially and circumferentially away from the clearance surface 72 on the first circumferential side relative to the motor axis AA. The clamping surface 78b extends radially and circumferentially away from the clearance surface 72 on the second circumferential side relative to the motor axis AA. Thus, the tooth 48 widens radially away from the clearance surface 72 along the height of the tooth 48 between the clamping surfaces 78a and 78b.

[0190] Contact surface 76 extends between the end of clamping surface 78a opposite to the clearance surface 72 and the end of clamping surface 78b opposite to the clearance surface 72. Lateral surface 80a extends between the end of clamping surface 78a and base surface 82. Lateral surface 80b extends between the end of clamping surface 78b and base surface 82. Each of lateral surfaces 80a and 80b may be planar. The width of tooth 48 between lateral surfaces 80a and 80b narrows along the height of tooth 48 away from clearance surface 72.

[0191] The plane along the lateral surface 80a is transverse to the plane of the clamping surface 78a and the plane along the lateral surface 80b. In some examples, the lateral surface 80a is arranged transversely to the plane of the clamping surface 78b. In other examples, the plane of the lateral surface 80a is parallel to the plane along the clamping surface 78b. Similarly, the plane along the lateral surface 80b is transverse to the planes of the clamping surface 78b and the lateral surface 80aa. In some examples, the plane along the lateral surface 80b is transversely to the plane of the clamping surface 78a. In other examples, the plane of the lateral surface 80b is parallel to the plane along the clamping surface 78a. The base surface 82 is a curved surface forming the end of the tooth 48 opposite to the clearance surface 72. The base surface 82 defines the end of the tooth 48 that is furthest from the air gap 30 during operation. The contact surface 76 is configured to directly contact and abut against the laminate of the retainer 46, as discussed in more detail below.

[0192] The second axial portion 70 protrudes axially from the first axial portion 68 relative to the motor axis AA. The second portion 70 is tapered such that the axial end 74b has a smaller cross-sectional area orthogonal to the motor axis AA than the axial end 74a. The second portion 70 tapers between its engagement with the first portion 68 and the axial end 74b. The cross-sectional area of ​​the second axial end 74, taken along a plane orthogonal to the motor axis AA, decreases between the engagement between the first portion 68 and the second portion 70 and the axial end 74b. The second portion 70 is partially defined by a clearance surface 72 and a profile portion 84. The profile portion 84 extends from a first circumferential side of the clearance surface 72 to a second circumferential side of the clearance surface 72. The profile portion 84 is formed by a curved wall that tapers between the first portion 68 and the axial end 74b to reduce the cross-sectional area of ​​the second portion 70. As the cross-sectional area of ​​the second portion 70 decreases, the clearance surface 72 maintains a constant profile on both the first portion 68 and the second portion 70. However, it should be understood that although the width of the gap surface 72 can vary in the second part 70, the profile of the gap surface 72 remains consistent. For example, the gap surface 72 can be planar in both the first part 68 and the second part 70.

[0193] The outer portion 84 may be smoothly tapered to provide a constant, smooth transition between the axial end 74b and the engagement between the first portion 68 and the second portion 70. The second portion 70 may have an axial rate of change of cross-sectional area from the axial end 74b to the flux-transmitting portion formed by the first portion 68, which may be constant, linear, or curved, without any inflection point or step in the rate of change. The outer portion 84 extends from and is integral with the contact surface 76 and the clamping surface 78.

[0194] In some examples, the axial end portion 74b includes a mating surface that is engaged by a tool or otherwise to force the tooth 48 out of the mold during manufacturing. In the illustrated example, the protrusion 86b forms an ejection feature to aid ejection from the mold during manufacturing and to prevent the formation of artificial marks on the tooth 48 during the ejection process. The protrusion 86b also facilitates assembly and provides a surface that can be engaged during press-fitting of the tooth 48 to the retainer 46. In the illustrated example, the protrusion 86b has a cross-sectional profile orthogonal to the axis AA, which is the same shape as the cross-sectional profile orthogonal to the axis AA of the axial end portion 74b, but the cross-section of the protrusion 86b has a smaller area. The protrusion 86b includes a profile edge to provide a smooth transition to the axial end portion 74b, which facilitates ejection during manufacturing and prevents the formation of artificial marks. In the illustrated example, the axial end portion 74a also includes a protrusion 86a similar to the protrusion 86b. The protrusion 86a provides a mating surface that can be contacted during the manufacturing and / or assembly of the tooth 48 and the retainer 46. In the example shown, the protrusion 86a has a cross-sectional profile orthogonal to the axis AA, which is the same shape as the cross-sectional profile orthogonal to the axis AA of the axial end 74a, but the cross-section of the protrusion 86a has a smaller area.

[0195] Figure 8 This is an enlarged isometric view of a portion of the flux ring 24, showing a retainer 46 for the flux protrusion 44 without teeth 48. The retainer 46 includes a retainer body 88; fingers 90a and 90b; a radial end 92; a receiving chamber 94; and outer sides 96a and 96b. The fingers 90a and 90b each include distal ends 98a and 98b; retaining portions 100a and 100b; seating portions 102a and 102b; and transition portions 104a and 104b.

[0196] Retainer 46 extends from branch 42 to radial end 92. Retainer 46 protrudes from branch 42 and is circumferentially spaced from adjacent retainers 46. Retainer 46 is formed of the laminate forming branch 42. Thus, retainer 46 can be integrally formed and integral with branch 42. The axial length HL of retainer 46 can be the same as the axial width of branch 42. In this way, retainer 46 can extend fully between the axial sides of branch 42. The axial length HL of retainer 46 remains constant along the radial height of the retainer relative to axis AA between branch 42 and radial end 92.

[0197] The retainer body 88 extends radially from the branch 42 to the receiving chamber 94. Finger portions 90a and 90b extend from the retainer body 88 and away from the branch 42. Finger portions 90a and 90b define the nearest air gap 30 of the retainer 46. Figure 1 and Figure 2A) and permanent magnet array 20 ( Figure 1 and Figure 2A (part of the text). Figure 8 The diagram shows the spacing 52 between adjacent retainers in retainer 46. As discussed above, the terminal retainer 46 on each branch 42 is spaced apart from the adjacent retainer 46 on the adjacent branch 42 by circumferential gaps 66a, 66b (in Figures 4A to 4C (Best viewed from the center). The retainer 46 widens between its engagement with the branch 42 and its radial end 92. The radial end 92 is the narrowest part of the retainer 46 in the circumferential direction.

[0198] Finger portions 90a and 90b are spaced apart to define a receiving chamber 94 between them. The fingers 90a and 90b extend from the base 110 of the retainer body 88 away from the receiving chamber 94 to distal ends 98a and 98b, respectively. The receiving chamber 94 includes axial openings 106a and 106b and a radial opening 108. The axial openings 106a and 106b and the radial opening 108 are each defined between the fingers 90a and 90b. The radial opening 108 is defined between the distal ends 98a and 98b. Thus, the receiving chamber 94 can be considered closed on three of its six sides. The receiving chamber 94 is open at both axial ends and at an end radially toward the air gap 30. The receiving chamber 94 is closed on the two circumferential sides formed by the finger-shaped portions 90a and 90b, and is also closed at the base 110.

[0199] The contours of the first finger 90a and the second finger 90b are configured to hold and retain the tooth 48 within the retaining cavity. Retaining portions 100a and 100b extend radially and circumferentially from the distal ends 98a and 98b, respectively, relative to the axis AA. Retaining portions 100a and 100b are formed on the circumferential inner walls of the fingers 90a and 90b, respectively. Each retaining portion 100a and 100b extends circumferentially away from the radial opening 108, such that the width of the receiving chamber 94 increases as the receiving chamber 94 extends away from the radial opening 108. Thus, the distal ends 98a and 98b protrude beyond a portion of the receiving chamber 94.

[0200] The retaining portions 100a and 100b extend to the transition portions 104a and 104b, respectively. The transition portions 104a and 104b are the inflection points between the retaining portions 100a and 100b and the seating portions 102a and 102b, respectively. The seating portions 102a and 102b extend radially and circumferentially from the transition portions 104a and 104b. The seating portions 102a and 102b extend circumferentially inward and converge toward the base 110. Thus, the width of the receiving chamber 94 narrows between the transition portions 104a and 104b and the base 110. The seating portions 102a and 102b each include seating surfaces 112a and 112b and base surfaces 114a and 114b, respectively. The corresponding base surfaces 114a and 114b extend toward each other to meet at the base 110 and form the base 110. The seating surfaces 112a and 112b can be planar. The plane along the surface of seating surface 112a is transverse to the plane along the surface of retaining portion 100a, and also transverse to the plane along the surface of seating surface 112b. The plane along the surface of seating surface 112a can be transverse to or parallel to the plane along the surface of retaining portion 100b. Similarly, the plane along the surface of seating surface 112b is transverse to the plane along the surface of retaining portion 100b, and also transverse to the plane along the surface of seating surface 112a. The plane along the surface of seating surface 112b can be transverse to or parallel to the plane along the surface of retaining portion 100a.

[0201] Although the receiving chamber 94 first widens and then narrows radially inward from the radial opening 108 to the base 110, the width of the retainer 46 between the outer sides 96a, 96b increases from the radial end 92 to the engagement with the branch 42. Similarly, the width of each finger 90a, 90b increases between the distal ends 98a, 98b and the base 110.

[0202] Figure 9A It is along Figure 5B An enlarged cross-sectional view of the magnetic flux protrusion 44, taken from line 9-9. Figure 9B yes Figure 9A The diagram shows a anatomical view of the flux protrusion 44. This will be discussed together. Figure 9A and Figure 9BThe flux protrusion 44 includes a retainer 46 and teeth 48. The retainer 46 includes a retainer body 88 and finger portions 90a and 90b. The retainer body 88 includes outer portions 96a and 96b. The finger portions 90a and 90b include distal portions 98a and 98b; retaining portions 100a and 100b; seating portions 102a and 102b; and transition portions 104a and 104b. The teeth 48 include a first portion 68, a second portion 70, a clearance surface 72, and axial ends 74a and 74b. The first portion 68 includes a contact surface 76 and clamping surfaces 78a and 78b. The contact surface 76 includes a lateral surface 80a, a lateral surface 80b, and a base surface 82. The second portion 70 includes a contour portion 84.

[0203] The flux protrusion 44 includes a tooth 48 supported by a retainer 46. In some examples, the retainer 46 is formed of a stacked laminate, and the tooth 48 is formed of powder metal. The retainer 46 is configured to engage the tooth 48 and hold the tooth 48 within a receiving chamber 94. More specifically, fingers 90a, 90b are configured as resilient claws that apply a radial elastic force toward the branch 42 to the tooth 48 to seat the tooth 48 within the receiving chamber 94. The fingers 90a, 90b abut against the tooth 48 and force the tooth 48 radially into the base 110 to hold the tooth 48 in place and maintain contact between the tooth 48 and the retainer 46.

[0204] The first portion 68 of the tooth 48 is disposed within the receiving chamber 94 and directly abuts against the laminated stack of the retainer 46. The tooth 48 is configured to directly contact as much of the portion of the retainer 46 defining the receiving chamber 94 as possible to minimize the gap between the tooth 48 and the retainer 46 and to facilitate the transfer of electromagnetic flux. The magnetic flux flows radially through the flux protrusion 44 to the axial return member 28 (in Figure 3A (Best viewed in the middle). The flux protrusion 44 is configured to facilitate radial flux flow through the laminate from the retainer 46 to the associated branch 42 (in the best view). Figures 4A to 4C (The best view in the middle).

[0205] The first portion 68 of tooth 48 includes an outer portion 116 and an inner portion 118. A clearance surface 72 and clamping surfaces 78a, 78b are formed on the outer portion 116. In the illustrated example, the outer portion 116 has a trapezoidal cross-sectional profile in a plane orthogonal to the motor axis AA. In the illustrated example, the inner portion 118 has a triangular cross-sectional profile truncated in a plane orthogonal to the motor axis AA, the profile having a circular base feature formed by the base surface 82. The inner portion 118 can be considered to have a U-shaped cross-sectional profile. In the illustrated example, the inner portion 118 has a U-shaped cross-sectional profile that narrows in width along the height of tooth 48 between the legs of the U and toward the end of the tooth opposite to the clearance surface 72. However, it should be understood that not all examples are constructed in this way.

[0206] The clearance surface 72 of the tooth 48 is disposed between the distal end 98a of the first finger 90a and the distal end 98b of the second finger 90b. The clearance surface 72 is exposed through the radial opening 108 of the receiving chamber 94. The clearance surface 72 is exposed to the air gap 30 formed between the stator 14 and the rotor 12. Figure 1 and Figure 2A In some examples, the gap surface 72 is planar with the distal ends 98a, 98b. Thus, the radial end of the flux protrusion 44 exposed to the air gap 30 can be partially formed by the retainer 46 and partially by the tooth 48.

[0207] The teeth 48 each have a first width TW1 at the gap surface 72; a second width TW2 at the engagement portion between the clamping surfaces 78a, 78b and the lateral surfaces 80a, 80b; and a third width TW3 near the engagement portion between the lateral surfaces 80a, 80b and the base surface 82. The first width TW1 extends across the gap surface 72 and is the width of the most radial portion of the teeth 48 toward the air gap 30. The second width TW2 is greater than the first width TW1 as the clamping surfaces 78a, 78b extend circumferentially away from the radial opening 108. The third width TW3 is narrower than the second width TW2 because the contact surface 76 narrows as it extends away from the clamping surfaces 78a, 78b. The third width TW3 is shown at a radial position where the planar lateral surfaces 80a, 80b transition to the curved base surface 82. In the example shown, the third width TW3 is narrower than both the second width TW2 and the first width TW1. However, it should be understood that in some examples, the third width TW3 may be the same as or greater than the first width TW1.

[0208] The retainer 46 abuts against and directly contacts the tooth 48 to hold the tooth 48 in the receiving chamber 94. The retainer 46 includes outer surfaces 96a and 96b, which respectively include first surfaces 120a and 120b and second surfaces 122a and 122. The retainer 46 defines the receiving chamber 94. The outer portion of the receiving chamber 94 extending between the radial opening 108 and the transition portions 104a and 104b may have a trapezoidal cross-sectional profile orthogonal to the axis AA to receive and abut against the trapezoidal cross-sectional profile of the outer portion 116 of the tooth. The inner portion of the receiving chamber 94 between the transition portions 104a and 104b and the base 110 may have a cross-sectional profile orthogonal to the axis AA, which is a triangle with a rounded apex to receive and abut against the inner portion 118 of the tooth. The inner portion of the receiving chamber 94 can be considered to have a U-shaped cross-sectional profile. In the example shown, the inner portion of the receiving chamber 94 has a U-shaped cross-sectional profile that widens along the height of the receiving chamber 94 from the base 110 toward the radial opening 108 between the legs of the U.

[0209] The tooth 48 and the retainer 46 are keyed together such that the tooth 48 directly abuts the retainer 46 on its two circumferential sides and at its radial end opposite to the radial opening 108.

[0210] The first finger-like portion 90a widens radially between the distal end 98a and the base 110. The first finger-like portion 90a has a first width FW1a at the distal end 98a. The first finger-like portion 90a has a second width FW2a at a radial position aligned with the transition portion 104a. The first finger-like portion 90a has a third width FW3a near the joint between the first surface 120a and the second surface 122a of the outer side 96a. The first finger-like portion 90a has a fourth width FW4a at a radial position at the transition between the sitting surface 112a and the base surface 114a. The first finger-like portion 90a has a fifth width FW5a near a radial position of the base 110. The first width FW1a is smaller than the second width FW2a, the second width FW2a is smaller than the third width FW3a, the third width FW3a is smaller than the fourth width FW4a, and the fourth width FW4a is smaller than the fifth width FW5a.

[0211] The finger-like portion 90a widens at a first rate between the position of the distal end 98a and the transition portion 104a, thereby increasing the width of the first finger-like portion 90a between the position of the first width FW1a and the position of the second width FW2a. The retaining portion 100a and the first surface 120a each extend relative to the axis AA in the same circumferential direction as the radial end 92 of these portions extending away from the retainer 46.

[0212] The third width FW3a is greater than both the second width FW2a and the first width FW1a. The third width FW3a is taken from a position near the joint between the first surface 120a and the second surface 122a of the outer side 96a. The finger-like portion 90a widens at a second rate between the radial position of the transition portion 104a and the radial position of the third width FW3a. The sitting portion 102a and the first surface 120a extend in a circumferential direction opposite to the direction in which these portions extend away from the radial end 92.

[0213] The fourth width FW4a is greater than each of the third width FW3a, the second width FW2a, and the first width FW1a. The fourth width FW4a is taken at the radial position of the transition between the seat surface 112a and the base surface 114a. The finger-like portion 90a widens at a third rate between the radial position of the transition portion 104a and the radial position of the fourth width FW4a. The seat portion 102a and the first surface 120a extend in a circumferential direction opposite to the direction in which the seat portion 102a and the second surface 122a extend away from the radial end 92.

[0214] The fifth width FW5a is greater than each of the fourth width FW4a, the third width FW3a, the second width FW2a, and the first width FW1a. The fifth width FW5a is taken near the radial position of the base 110 of the receiving chamber 94. The finger-like portion 90a widens at a fourth rate between the radial positions of the fourth width FW4a and the fifth width FW5a. The base surface 114a and the second surface 122a extend radially away from the radial end 92 in opposite circumferential directions along these portions.

[0215] The finger-like portion 90a widens at various rates between its distal end 98a and its engagement portion with the retainer body 88. A first rate can be the slowest widening rate. A second rate can be greater than the first rate, such that in portions having the second rate, the width of the finger-like portion 90a increases per unit distance along the radial height of the retainer 46 more than in portions having the first rate. A third rate can be less than the second rate. A third rate can be greater than the first rate. A fourth rate can be greater than any of the first, second, and third rates.

[0216] The finger-like portion 90b is configured similarly to the finger-like portion 90a and has a first width FW1b, a second width FW2b, a third width FW3b, a fourth width FW4b, and a fifth width FW5b. The width of the finger-like portion 90b is taken from the same relative position as the width of the finger-like portion 90a, except between the outer side 96b and the portion defining the receiving chamber 94 of the finger-like portion 90b (e.g., the third width FW3b is taken near the junction between the first surface 120b and the second surface 122b of the outer side 96b). The width of the finger-like portion 90b increases radially between the distal end 98b and the radial position of the base 110. Although the finger-like portion 90b is similar to the finger-like portion 90a, it should be understood that the finger-like portion 90b may differ from the finger-like portion 90a. In some examples, the slope of the portion forming the outer side 96a may differ from the slope of the portion forming the outer side 96b. For example, the terminal flux protrusion defining the circumferential gap 66 in the flux protrusion 44 may differ from other flux protrusions in the flux protrusion 44, since those flux protrusions 44 extend circumferentially beyond the branch 42. However, it should be understood that all flux protrusions 44 widen between the radial end 92 and the base 110.

[0217] A receiving chamber 94 formed between the first finger 90 and the second finger 90 has a first width RW1 at the radial end 92 of the retainer 46. The receiving chamber 94 has a second width RW2 at a radial position of the transition portions 104a, 104b. The receiving chamber 94 has a third width RW3 at a radial position between the transition portions 104a, 104b and the base 110. The first width RW1 extends between the distal ends 98a, 98b and is the width of the radial opening 108 exposed to the air gap 30 during operation. The second width RW2 is greater than the first width RW1 as the retaining portions 100a, 100b extend circumferentially away from the radial opening 108. The third width RW3 is narrower than the second width RW2 as the contact surfaces 76 converge along the seating portions 102a, 102b toward the branch 42. The third width RW3 is shown at a radial position where the seating surfaces 112a, 112b transition to the base surface 114. In the example shown, the third width RW3 is narrower than both the second width RW2 and the first width RW1.

[0218] The actual width of the flux protrusion 44 is taken from the width between the outer sides 96a and 96b. The laminate width of the flux protrusion 44 is the combined width of those portions of the flux protrusion 44 formed by the stacked laminates at a given radial position between the branch 42 and the radial end 92 of the retainer 46. The laminate width does not include the width of the powder metal at a given radial position. At some radial positions, the actual width of the flux protrusion 44 is the same as the laminate width of the flux protrusion 44. At other radial positions (e.g., between the radial opening 108 of the receiving chamber 94 and the base 110), the actual width of the flux protrusion 44 is greater than the laminate width of the flux protrusion 44 because those portions of the flux protrusion 44 include the powder metal teeth 48. For example, the laminate width refers to the combined width of finger-like portions 90a and 90b at radial positions along the flux protrusion 44, which includes the receiving chamber 94, while the actual width at these positions is the width of the retainer 46 between the outer edges 96a and 96b. Both the laminate width and the actual width of the flux protrusion 44 increase from the radial end 92 toward the branch 42. Both the laminate width and the actual width can increase at all radial positions between the radial end 92 and the branch 42. At some radial positions, the width of the tooth 48 is greater than the laminate width of the flux protrusion 44. For example, along the entire radial height of the outer portion 116 of the tooth, the outer portion 116 is wider than the laminate width of the flux protrusion 44.

[0219] In the portion of the flux protrusion 44 extending from the radial opening 108 to the transition portions 104a, 104b and toward the branch 42, each of the laminate width, tooth width, and actual width increases. In the portion of the flux protrusion 44 extending from the transition portions 104a, 104b toward the base 110, both the laminate width and actual width increase while the tooth width decreases.

[0220] The tooth 48 is fixed within the receiving chamber 94 by the fingers 90a and 90b. In the illustrated example, the tooth 48 directly abuts against the retainer 46 in three contact areas. A first contact area is formed between the fingers 90a and the tooth 48. More specifically, the first area is formed where the retainer 100a directly contacts the clamping surface 78a and applies a force with a radial component toward the branch 42 to the tooth 48. A second contact area is formed between the fingers 90b and the tooth 48. More specifically, the second area is formed where the retainer 100b directly contacts the clamping surface 78b and applies a force with a radial component toward the branch 42 to the tooth 48. The clamping surface 78a is disposed on plane P1, and the surface of the retainer 100a is disposed on plane P2. Plane P1 is disposed transverse to plane P2 such that only a portion of the engagement between the clamping surface 78a and the opposing portion of the retainer 100a includes direct contact between the retainer 46 and the tooth 48. The clamping surface 78b and the retaining portion 100b are configured to be similar to the clamping surface 78a and the retaining portion 100a.

[0221] A third contact area is formed between the seating portions 102a, 102b and the contact surface 76. The third contact area is provided on each circumferential side of the tooth 48 and surrounds the tooth 48 between the two sides. No air gap is formed in the contact area, which facilitates effective magnetic flux transmission through the magnetic flux protrusion 44.

[0222] The first width RWl of the receiving chamber 94 (which is also the distance between the fingers 90a and 90b) can be smaller than the first width TWl of the tooth 48. In some examples, the first width TWl of the tooth 48 is one percent, three percent, or up to five percent wider than the first width RWl of the receiving chamber 94. This difference in width allows the fingers 90a and 90b to apply a spring force to the tooth 48 to seat it within the receiving chamber 94. The fingers 90a and 90b act as spring clips that apply force to the tooth 48 to seat it within the receiving chamber 94. Each finger 90a and 90b applies a force having both radial and circumferential components. The circumferential components can cancel each other out, causing the fingers 90a and 90b to radially drive the tooth 48 into the receiving chamber 94 and away from the air gap 30, thereby minimizing the air gap between the tooth 48 and the retainer 46.

[0223] The engagement between tooth 48 and retainer 46 forces the tooth downward into receiving chamber 94, creating direct contact in the third contact area and between the seating portions 102a, 102b and contact surface 76. First finger 90a and second finger 90b form resilient claws that apply radial force to tooth 48 to drive engagement in the third contact area. The radius of the curved portion of receiving chamber 94 (e.g., the radius of the curve defined by base surfaces 114a, 114b) can be slightly smaller than the radius of the curved portion of tooth 48 (formed by base surface 82). The smaller radius of receiving chamber 94 compared to tooth 48 provides a tight contact fit between tooth 48 and retainer 46. The elasticity of fingers 90a, 90b pushes tooth 48 downward, radially aligning clearance surface 72 with the distal ends 98a, 98b of fingers 90a, 90b. Clearance surface 72 is directly exposed to the air gap 30 between rotor 12 and stator 14.

[0224] Finger portions 90a, 90b collect magnetic flux near their distal ends 98a, 98b. Increasing the laminar width and finger width on the circumferential side of the receiving chamber 94 provides additional areas for magnetic flux flow through the flux protrusion 44, thereby reducing the magnetic flux density in these areas. Extending the width of the retainer 46 away from the radial end 92 and toward the branch 42 reduces the magnetic flux density. Reducing the width of the inner portion 118 of the tooth from the transition portions 104a, 104b toward the base 110 and extending the laminar width further enhances magnetic flux transmission. The reduced magnetic flux density facilitates radial magnetic flux flow through the flux protrusion 44, thereby providing efficient operation in a lightweight and compact manner. The flux protrusion 44 does not include a tooth that widens circumferentially at the base of the tooth. In some examples, the tooth 48 includes a smooth, converging surface near the base 110 and does not include an abrupt transition. However, it should be understood that embodiments of the tooth 48 are not necessarily constructed in this way.

[0225] A first tooth gap 117a is circumferentially disposed between the tooth 48 and the first finger 90a, and a second tooth gap 117b is circumferentially disposed between the tooth 48 and the second finger 90b. The first tooth gap 117a is disposed between the first contact area and the third contact area. The second tooth gap 117b is disposed between the second contact area and the third contact area. A gap between the tooth 48 and the retainer 46 when they are not in direct contact is generally undesirable, as such a gap would inhibit magnetic flux flow. The radial portion of the magnetic flux protrusion 44, formed by the outer portion 116 of the tooth and the adjacent portions of the fingers 90a and 90b, collects magnetic flux that flows radially through the laminate and toward the axial return member 28. The radially outer end of the magnetic flux protrusion 44 is rich in magnetic flux that flows radially to the magnetic flux protrusion 44. The mating between the tooth 48 and the retainer 46 is configured such that the first tooth gap 117a and the second tooth gap 117b are respectively circumferentially disposed between the retaining portions 100a, 100b and the clamping surfaces 78a, 78b in the flux-rich region of the flux protrusion 44. After the tooth 48 is assembled to the retainer 46, the tooth gaps 117a, 117b are filled with a potting compound. During potting, the retainer 46 maintains the desired position and orientation of the tooth 48.

[0226] The tooth gaps 117a and 117b are radially positioned closer to the air gap 30 than to the base 110. The tooth gaps 117a and 117b are radially positioned between the gap surface 72 and the engagement portion between the lateral surfaces 80a and 80b and the clamping surfaces 78a and 78b. Thus, the tooth gaps 117a and 117b are radially positioned between the widest portion of the tooth 48 and the distal ends 98a and 98b. The tooth gaps 117a and 117b are positioned in the flux-rich region of the flux protrusion 44, where the flux is high. Positioning the tooth gaps 117a and 117b in this region minimizes the impact of gaps compared to gaps in low flux density regions. The tooth gaps 117a and 117b are radially positioned outside the radial portion of the flux protrusion 44 defined by the inner portion 118 of the tooth and the adjacent portions of the finger-like portions 90a and 90b in the circumferential direction. Thus, the tooth gaps 117a and 117b are radially disposed outside this portion of the magnetic flux protrusion 44, in which the teeth 48 narrow circumferentially and each finger 90a and 90b has a wall extending in each circumferential direction. The increase in the width of the laminate caused by the narrowed teeth 48 and the corresponding widened fingers 90a and 90b provides efficient magnetic flux transmission during motor operation.

[0227] During the assembly of the flux ring 24, the tooth 48 can be axially inserted into the retainer 46. The tooth 48 is press-fitted into the receiving chamber 94 and held by the fingers 90a and 90b. Figure 5DIdeally, with the tooth 48 mounted to the retainer 46, each axial end 74a, 74b of the tooth 48 can protrude beyond the receiving chamber 94. The profile of the tooth 48 is aligned with the profile of the receiving chamber 94, and the tooth 48 is axially offset relative to the axis AA such that the tooth 48 passes through the axial openings 106a, 106b of the receiving chamber 94. Figure 8 The tooth 48 enters the receiving chamber 94. For example, the axial end 74a can be aligned with the axial opening 106a such that the first portion 68 is the first portion of the tooth 48 that enters the receiving chamber 94 and abuts against the retainer 46. Fingers 90a and 90b apply radial forces to the tooth 48 at clamping surfaces 78a and 78b, respectively, to seat the tooth 48 within the receiving chamber 94. Axially inserting the tooth 48 into the receiving chamber 94 can force the fingers 90a and 90b to separate, causing them to apply a spring force to the tooth 48 to seat it. In some examples, the tooth 48 can be inserted by applying an axial force to one of the protrusions 86a and 86b. The mating between the fingers 90a and 90b and the tooth 48 is a press-fit connection, which offers high precision and ease of assembly. Through the potting step of the manufacturing process, the fingers 90a and 90b hold the teeth 48 relative to the retainer 46.

[0228] The flux protrusion 44 offers significant advantages. Fingers 90a and 90b hold the tooth 48 within the receiving chamber 94. The fingers 90a and 90b clamp the tooth 48 to the retainer 46 such that the tooth gap between the retainer 46 and the tooth 48 is minimized, and any remaining tooth gap is positioned advantageously with high flux density, thus not inhibiting flux flow. The engagement between the tooth 48 and the retainer 46 facilitates radial flux flow through the flux protrusion 44. The fingers 90a and 90b act as resilient claws, firmly holding the tooth 48 in place on the retainer 46. Widening the laminate width and actual width along the flux protrusion 44 away from the air gap 30 and toward the branch 42 reduces the flux density toward the branch 42 and away from the air gap 30. This radial widening facilitates efficient flux flow through the flux protrusion 44, thereby generating an electromagnetic field and driving the rotation of the rotor 12. The tooth 48 narrows within the receiving chamber 94, and the fingers 90a and 90b widen in each circumferential direction to smoothly and rapidly reduce the magnetic flux density radially away from the permanent magnet array 20 and to promote radial magnetic flux flow.

[0229] Figure 10This is a side view of phase assembly 22a. The flux loops 24a and 24b and coil 26 of phase assembly 22a are shown as 28. Flux loop 24a includes a flux protrusion 44a formed by a retainer 46a and teeth 48a. Flux loop 24b includes a flux protrusion assembly 22b having a flux protrusion 44b formed by a retainer 46b and teeth 48b.

[0230] As discussed above, the second portion 70 of each tooth 48a, 48b extends axially over the coil 26. The teeth 48a, 48b extend partially across the axial length of the coil 26. The teeth 48a, 48b do not extend over the entire axial length of the coil 26; however, it should be understood that not all examples are so restricted. The tapered second portion 70 has tapered tooth offset distances OD1, OD2 that are uniform and constant over the axial length of the second portion 70 of each tooth 48a, 48b in which the teeth 48a, 48b circumferentially overlap. This uniform and constant tapered tooth offset distance provides more uniform magnetic flux transfer and reduced magnetic flux leakage.

[0231] Figure 11A This is a first isometric view of the stator 14 with the potting sleeve 128 in its first state. Figure 11B This is a second isometric view of the stator 14 with the potting sleeve 128 in the second state. Figure 11C This is a third isometric view of the stator 14 with the potting sleeve 128 in its second state, and the insert 130 is shown. These will be discussed together. Figures 11A to 11C The stator 14 includes a phase assembly 22, stator ends 124a and 124b, and a center hole 126. The sleeve 128 includes an inner sleeve 132 and an outer sleeve 134.

[0232] Phase assembly 22 is disposed along and extends about the motor axis AA. As discussed above, the phase assembly 22 is positioned in a relative operating position relative to each other and is arranged along the motor axis AA. Each phase assembly 22 rotates relative to each other about the motor axis AA when in its operating position.

[0233] With phase assembly 22 in the corresponding operating position, a potting compound, such as epoxy resin, is added to stator 14. The potting compound is embedded in phase assembly 22. The potting compound embeds flux ring 24 within the potting compound. The axial side of flux ring 24 is fully embedded in the potting compound. Thus, each of branch 42 and trunk 40 is fully embedded in the potting compound. In some examples, coil 36 is fully embedded in the potting compound. The potting compound is continuous from the cylindrical outer circumference to the cylindrical inner circumference of stator 12. In some examples, the potting compound is continuous with motor axis AA (e.g., in examples excluding insert 130).

[0234] Sleeve 128 and insert 130 are used during the potting process to minimize the amount of potting material used and to facilitate the connection between stator 14 and rotor 12. Figure 1 and Figure 2A The air gap between 30 ( Figure 1 and Figure 2A (Small size)

[0235] Sleeve 128 is elastic and has a relaxed diameter (the diameter of sleeve 128 in its relaxed state) smaller than the diameter D1 of stator 14. For example, sleeve 128 can be formed of an elastomer or the like. Sleeve 128 is initially in a rolled-up configuration with the sleeve interior 132 facing outwards. Sleeve 128 is placed on stator end 124a and axially unfolded along motor axis AA and on the outside of stator 14. As sleeve 128 rolls on the outside of stator 14, sleeve 128 is turned outwards such that sleeve interior 132 faces stator 14 and abuts against stator 14, and sleeve exterior 134 is away from stator 14. Due to the different diameters between sleeve 128 and stator 14, sleeve interior 132 directly abuts against the outside of stator 14. Thus, sleeve interior 132 directly abuts against the radial end of flux protrusion 44 of each phase assembly 22. The sleeve interior 132 can directly mate with one or both of the tooth 48 and the retainer 46. The sleeve interior 132 can directly mate with the clearance surface 72 of the tooth 48. The sleeve 128 continues to roll along the length of the stator 14 until it reaches the desired position. Figure 11B and Figure 11C The second state is shown. In the second state, the sleeve 128 extends between the stator ends 124a and 124b and radially encloses the stator 14.

[0236] An insert 130 is disposed in the center bore 126 of the stator 14. The insert 130 is configured to abut against the inside of the stator 14, for example by contacting the radially inner side of the ring body 36 of the flux ring 24 of each phase assembly 22. The insert 130 can be inserted axially into the center bore 126 along the motor axis AA. The insert 130 can be a plug that abuts against the stator 14. In some examples, the insert 130 can be configured as a bladder filled with fluid to extend radially outward, thereby filling the center bore 126 and contacting the stator 14.

[0237] The stator 14 is radially supported by a sleeve 128 and an insert 130. The sleeve 128 and the insert 130 form a can for a filling process. A potting compound can be applied to the stator 14 between the sleeve 128 and the insert 130. As discussed above, some examples do not include the insert 130, such that the sleeve 128 forms a can for a filling process.

[0238] The difference in diameter between the sleeve 128 and the stator 14 causes a portion of the sleeve 128 to radially contract inward within the gap between the flux protrusions 44. This results in a pit 136 forming in the outer radial surface of the cured potting compound. Figure 12A and Figure 12B The recess 136 can be formed in the gap 52 between adjacent flux protrusions in the flux protrusion 44 (in Figures 4A to 4C In the best view, the circumferential gaps 66a and 66b between adjacent flux protrusions formed circumferentially in the flux protrusions 44 between the teeth 48 of the same flux ring 24 (in the best view) Figures 4A to 4C (best seen in the middle) and in the circumferentially arranged gap between the teeth 48 of the magnetic flux protrusions forming in the magnetic flux protrusions 44.

[0239] The pit 136 is formed during the potting process, not by machining after the potting compound has cured. Thus, the pit 136 can be irregularly formed in the air gap surface of the stator 12 (the surface of the stator 12 exposed to the air gap 30). The pit 136 can have irregular depths, can be formed between some pairs of teeth 48 but not between other pairs of teeth 48, can be formed at different locations between different pairs of teeth 48, etc. The elasticity of the sleeve 128 causes the irregularity of the pit 136.

[0240] The difference in diameter between the sleeve 128 and the stator 14 facilitates direct contact between the sleeve 128 and the clearance surface 72 of the tooth 48. This removes a gap between the clearance surface 72 of the tooth 48 and the can partially formed by the sleeve 128. The sleeve 128 thus prevents the potting compound from solidifying on the clearance surface 72, allowing the clearance surface 72 to be directly exposed to the air gap 30 between the stator 14 and the rotor 12. In this way, powder metal components (e.g., the tooth 48) can be directly exposed to the air gap 30. The clearance surface 72 of one or more teeth 48 can be directly exposed to the air gap 30 without machining the tooth 48 to remove the potting compound. It should be understood that some teeth of the tooth 48 may have a layer of insignificant potting compound on the clearance surface 72, which could lead to leakage between the sleeve 128 and the tooth 48.

[0241] Removing the radial clearance between the stator 14 and the can prevents the potting compound from solidifying on the clearance surface 72 and from extending radially outward beyond the teeth 48. No machining of the stator 14 is required to remove the potting compound and expose the teeth 48. Preventing the potting compound from extending radially beyond the teeth 48 allows the permanent magnet array 20 to be closer to the stator 14 without concern for contact between the potting compound and the rotor 12. This allows for a reduction in the radial dimension of the air gap 30, thereby improving motor efficiency and providing a more compact arrangement of the motor 10.

[0242] Figure 12A This is an enlarged end view showing a portion of the stator 14 and the recess 136. Figure 12B This is a partial side view of the stator 14 showing the recess 136. It will be discussed together. Figure 12A and Figure 12B The phase assemblies 22a-22c of stator 14 are shown. Figure 12B The flux loop 24a is shown. Figure 12A ) ring body 36 ( Figure 12A ), main trunk 40 ( Figure 12A Branch 42 ( Figure 12A ) and flux protrusion 44. Flux protrusion 44 includes retainer 46 and tooth 48. The clearance surface 72 of tooth 48 is shown.

[0243] Because pits 136 are formed in the potting compound between the teeth 48, the outer surface of the stator 14 is irregular and contoured. Pit 136 is formed in the surface of the stator 12 exposed to the air gap 30 during operation. In the illustrated example, pit 136 is formed at the radial outer edge of the stator 14. Pit 136 extends radially away from the radial end of the flux protrusion 44. Thus, directly after the potting process is completed, the flux protrusion 44 can form the outermost (or, in other examples, the innermost) radial portion of the stator 14. More specifically, the exposed clearance surfaces 72 of the teeth 48 form the outermost radial portion of the stator 14. Figure 12B Ideally, the recess 136 can be formed circumferentially between the teeth 48 of the same flux ring 24 in the gap between adjacent flux protrusions in the flux protrusion 44, in the circumferentially arranged gap between the teeth 48 of the paired flux protrusions in the flux protrusion 44, and in the axial gap between adjacent phase assemblies 22 (e.g., Figure 6C As shown, along axis AA between magnetic flux protrusions 44b and 44c.

[0244] The recess 136 reduces the amount of potting material used during the potting process, thus saving costs and materials. The recess 136 also provides a variable surface of the stator 14 exposed to the air gap 30. The recess 136 thereby reduces the weight of the motor 10. Additionally, the recess 136 provides a location to collect any debris entering the air gap 30 between the stator 14 and the rotor. The recess 136 can collect and trap contaminants entering the air gap 30, thus preventing these contaminants from interfering with the rotor 12. Unlike smooth circumferential surfaces, debris can be collected in the recess 136 and thereby removed from the air gap 30, preventing potential contact damage caused by debris. The recess 136 provides a variation in the air gap surface of the stator 14 exposed to the air gap 30 during operation. This results in a variation in the dimensions of the mechanical air gap 30 between the stator 14 and the rotor 12. This variation in the dimensions of the mechanical air gap 30 makes the motor 10 less susceptible to damage at the mating point between the rotor 12 and the stator 14.

[0245] As shown in the figure, pits 136 are irregularly formed in the air gap surface of the stator 12 exposed to the air gap 30. The pits 136 may have irregular depths; some pits 136 may be formed in a first region between adjacent teeth 48, while others may be formed in regions different from the first region between other adjacent pairs of teeth 48. In some examples, pits 136 may be formed between some pairs of teeth 48, while not between other pairs of teeth 48. Therefore, the pit profile can vary between different pairs of teeth 48.

[0246] Figure 13 This is a perspective end view of the stator 14, showing a recess 136 in the air gap surface of the stator 14. The stator 14 is embedded in a potting compound 146. The potting compound 146 is embedded in the stator 14 such that the axial side of the flux ring 24 is completely embedded within the potting compound 146. Portions of the teeth 48 (e.g., the clearance surface 72) and portions of the retainers 46 (e.g., the distal ends 98a, 98b of each finger 90a, 90b) are exposed from the potting compound 146 to the air gap 30 formed between the stator 14 and the rotor 12. As shown, the potting compound 146 extends the entire radial extent of the stator 14 to the hub 148 on which the stator 14 is mounted.

[0247] Recesses 136 are formed between teeth 48. Recesses 136 are formed during the potting process. Recesses 136 are irregularly formed on the air gap surface of the stator 14. The profile of recesses 136 can vary relative to other recesses in the recesses 136. As shown, the air gap surface of the stator 14 has a relatively smooth profile near stator end 124b, and more defined recesses 136 near stator end 124a. Recesses 136 are formed such that the stator 14 has an irregularly profiled surface exposed to the air gap 30. Recesses 136 can extend axially between teeth 48 and circumferentially between teeth 48.

[0248] The recess 136 also provides a variable surface of the stator 14 exposed to the air gap 30. The recess 136 thereby reduces the weight of the motor 10. Additionally, the recess 136 provides a location to collect any debris entering the air gap 30 between the stator 14 and the rotor 12. Capturing contaminants in the recess 136 prevents these contaminants from adversely affecting the operation of the rotor 12.

[0249] Figure 14A This is an end view of part of the flux ring 24' and insert 130'. Figure 14B It is similar to Figure 14A The end view shows the flux ring 24' after the potting compound has cured and the insert 130' has been removed. The flux ring 24' includes a ring body 36', a trunk 40', branches 42', and flux protrusions 44'.

[0250] In the example shown, flux ring 24' is used for the stator in an internal rotor motor, wherein the rotor is radially disposed within the stator 14'. Thus, ring body 36' forms the radially outer portion of flux ring 24' relative to the rotor's axis of rotation. Main trunk 40' extends radially inward from ring body 36'. Branch 42' is supported by main trunk 40'. Flux protrusion 44' extends radially inward from branch 42'. In the example shown, flux protrusion 44' is a laminated component, but it should be understood that some examples of flux protrusion 44' include powder metal components, such as teeth 48 (in...). Figures 7A to 7E (Best viewed in the middle). The circumferential clearance 66' is similar to clearances 66a and 66b (in the middle). Figures 4A to 4C (best seen in the middle) and extends radially between branches. The gap 52' is similar to gap 52 (in...). Figures 4A to 4C (best seen in the middle) and extends circumferentially between adjacent flux protrusions in flux protrusion 44.

[0251] Insert 130' is formed in the radially inner portion of the can used during the filling process. Similar to sleeve 128 ( Figures 11A to 11CThe sleeve of the flux ring 24' can be arranged around the outside of the stator to form the outer portion of the container. In some examples, because the flux ring 24' is used for an internal rotor motor, the radially outer side of the stator is not exposed to the mechanical air gap; therefore, a rigid outer sleeve, metal tube, or other container can be used for the radially outer side of the flux ring 24'. The insert 130' can be elastic and extends through the central bore of the stator. The insert 130' is inserted into the stator and expands radially outward into the circumferential gap 66' and the spacer gap 52' between the flux protrusions 44'. For example, the insert 130 can be a bladder configured to be filled with fluid, or it can be a compression assembly, etc. Figure 14B As shown, the pit 136 is formed in the potting mix between the magnetic flux protrusions 44.

[0252] The recesses 136 are formed in varying depths on the air gap surface of the stator. As shown, the recesses 136 are irregularly formed on the air gap surface of the stator 12 exposed to the air gap. The recesses 136 can have irregular depths; some recesses 136 can be formed in a first region between adjacent teeth 48, while others can be formed in regions different from the first region between other adjacent tooth pairs in the teeth 48. In some examples, the recesses 136 can be formed between some tooth pairs of teeth 48, while the recesses 136 are not formed between other tooth pairs of teeth 48. The recess profile can therefore vary between different tooth pairs of teeth 48. The recesses 136 reduce the weight of the internal rotor motor and the material cost of the motor. In addition, the recesses 136 provide a way to collect air entering the air gap between the stator and rotor (similar to air gap 30). Figure 1 and Figure 2A The location of any debris. Variations in the size of the mechanical air gap make the motor less susceptible to damage at the mating point between the rotor and stator.

[0253] Figure 15 This is a schematic diagram of the insert 130'' within the stator 14' of an internal rotor motor. The stator 14' includes phase assembly 22a', phase assembly 22b', and phase assembly 22c'. The insert 130'' and the insert 130' ( Figure 14A They are essentially similar and are configured to contact the flux protrusions 44' in each phase assembly 22a'-22c'. Figure 14A and Figure 14B ), so as to form pits 136 in the potting compound.

[0254] An expansion assembly 138 extends through the interior of the insert 130''. The expansion assembly 138 includes an extension 140, a plate 142, and an adjuster 144. The expansion assembly 138 extends through the insert 130'' and is configured to cause the insert 130'' to expand radially to contact the phase assemblies 22a'-22c'. The plate 142 is disposed on opposite axial ends of the stator 14'. The extension 140 extends through the insert 130'' and is operably connected to the plate 142. For example, the extension 140 may be a rod extending through the insert 130'' and through the plate 142. The adjuster 144, which may be a nut connected to the threaded end of the extension 140, is used to move the plate 142 axially closer together, thereby providing a compressive force on the insert 130''. The compressive force causes the insert 130'' to expand radially within the stator 14' to abut against the phase assemblies 22a'-22c'.

[0255] Although the invention has been described with reference to one or more exemplary embodiments, those skilled in the art will understand that various different changes can be made and equivalents can be substituted for elements therein without departing from the scope of the invention. Furthermore, many modifications can be made to adapt particular situations or materials to the teachings of the invention without departing from the scope of the invention. Therefore, it is intended that the invention be limited to the specific embodiments disclosed, but rather that the invention encompass all embodiments falling within the scope of the appended claims.

Claims

1. A flux ring for a phase assembly of a stator of a transverse flux electric motor, the flux ring comprising: a ring body disposed about a motor axis; a plurality of stems extending radially from the ring body; a plurality of branches supported by the plurality of stems and radially distanced from the ring body such that a plurality of return openings are formed between the ring body and the plurality of branches; a plurality of flux projections extending from the plurality of branches and radially distanced from the ring body; a first plurality of gaps, each gap of the first plurality of gaps disposed circumferentially between adjacent flux projections of the plurality of flux projections; and a second plurality of gaps, each gap of the second plurality of gaps disposed circumferentially between adjacent branches of the plurality of branches; wherein the second plurality of gaps are asymmetrically disposed about the motor axis such that a first pair of adjacent branches of the plurality of branches are spaced apart by a first circumferential gap, a second pair of adjacent branches of the plurality of branches are spaced apart by a second circumferential gap, and the first circumferential gap is greater than the second circumferential gap. a terminal flux projection of a first branch of the first pair of adjacent branches circumferentially projects from the first branch.

2. The magnetic flux ring of claim 1, wherein, each branch of the plurality of branches supports a subset of the plurality of flux projections, and wherein each subset of the plurality of flux projections is circumferentially offset relative to the stem supporting the branch.

3. The flux ring of claim 1, wherein, each return opening comprises:

4. The magnetic flux ring of claim 3, wherein, a first receiving portion receiving a portion having a first radial side formed by a base of a first branch; and a second receiving portion having a second radial side formed by a base of a second branch. the base of the first branch has a first width and the base of the second branch has a second width, and wherein the first width is the same as the second width.

5. The magnetic flux ring of claim 4, wherein, each stem of the plurality of stems defines a first circumferential side of a first return opening of the plurality of return openings and a second circumferential side of a second return opening of the plurality of return openings, and wherein the plurality of stems are asymmetrically disposed about the motor axis.

6. The magnetic flux ring of any one of claims 3-5, wherein, each branch of the plurality of branches comprises a first radial base extending from the stem supporting the branch in a first circumferential direction and a second radial base extending from the stem supporting the branch in a second circumferential direction, and wherein the first radial base is disposed transverse to the second radial base.

7. The magnetic flux ring of claim 6, wherein, the first radial base has a first width and the second radial base has a second width, and wherein the first width is the same as the second width.

8. The magnetic flux ring of claim 7, wherein, 9. A phase assembly for a transverse flux electric motor, the phase assembly comprising: a first flux ring disposed about a motor axis; a second flux ring axially spaced apart from the first flux ring; a coil axially disposed between the first flux ring and the second flux ring; and a plurality of flux projections extending from the plurality of branches and radially distanced from the ring body; a plurality of axial returns extending between the first flux ring and the second flux ring, wherein each axial return of the plurality of axial returns extends into a first return opening of the first flux ring and a second return opening of the second flux ring; wherein the plurality of axial returns are asymmetrically disposed about the motor axis such that a first axial return of the plurality of axial returns is circumferentially adjacent to a second axial return of the plurality of axial returns and a third axial return of the plurality of axial returns, and a first circumferential gap between the first axial return and the second axial return is greater than a second circumferential gap between the first axial return and the third axial return.

10. The phase assembly of claim 9, further comprising: a first coil connector of the coil extending from the coil and radially through a return gap formed between a first axial return of the plurality of axial returns and a second axial return of the plurality of axial returns; and a second coil connector of the coil extending from the coil and radially through the return gap.

11. The phase assembly of claim 10, wherein, the plurality of axial returns are disposed on a first radial side of the coil, wherein the first coil connector extends from the first radial side of the coil to the return gap, and wherein the second coil connector extends around an axial side of the coil to the return gap.

12. The phase assembly of claim 11, wherein, at least a portion of the second coil connector is circumferentially disposed between laminate portions of the first flux ring.

13. The phase assembly of claim 12, wherein, the second coil connector is not axially bracketed between the first flux ring and the coil.

14. The phase assembly of any of claims 11-13, wherein: the first flux ring comprises: a first ring body disposed about the motor axis; a first plurality of stems extending radially from the first ring body; a first plurality of branches supported by the first plurality of stems and radially distanced from the first ring body such that a plurality of the first return openings are formed between the first ring body and the first plurality of branches; a first plurality of flux projections extending from the first plurality of branches and radially distanced from the first ring body; and a first plurality of gaps, each gap circumferentially disposed between adjacent branches of the first plurality of branches; and the second coil connector extends axially relative to the coil and into a first gap of the first plurality of gaps.

15. The phase assembly of claim 14, wherein, the first plurality of flux projections are asymmetrically disposed about the motor axis.

16. The phase assembly of claim 15, wherein, the first plurality of branches are asymmetrically disposed about the motor axis.

17. The phase assembly of claim 14, wherein: the second flux ring comprises: a second ring body disposed about the motor axis; a second plurality of stems extending radially from the second ring body; a second plurality of branches supported by the second plurality of stems and radially distanced from the second ring body such that a plurality of the second return openings are formed between the second ring body and the second plurality of branches; a second plurality of flux projections extending from the second plurality of branches and radially distanced from the second ring body; and a second plurality of gaps, each gap circumferentially disposed between adjacent branches of the second plurality of branches. a second plurality of struts extending radially from the second ring body; a second plurality of branches supported by the second plurality of struts and radially distanced from the second ring body such that a plurality of the second return openings are formed between the second ring body and the second plurality of branches; a second plurality of flux protrusions extending radially from the second plurality of branches and distanced from the second ring body; and a second plurality of gaps, each gap of the second plurality of gaps being circumferentially disposed between adjacent branches of the second plurality of branches; the coil is axially disposed between the first plurality of branches and the second plurality of branches.

18. An electric motor comprising: a rotor that rotates about a motor axis; and a stator comprising at least one phase, each phase comprising: a first flux ring comprising a first plurality of struts and a first plurality of flux protrusions supported by the first plurality of struts, wherein the first plurality of struts are non-uniformly circumferentially arranged about the motor axis; a second flux ring comprising a second plurality of struts and a second plurality of flux protrusions supported by the second plurality of struts; and a coil coaxial with the motor axis and directly between the first flux ring and the second flux ring, the coil configured to be energized to electromagnetically polarize flux of the first plurality of flux protrusions relative to the second plurality of flux protrusions; wherein the first plurality of struts are non-uniformly circumferentially arranged about the motor axis such that a first pair of adjacent struts of the first plurality of struts has a first separation distance therebetween, and a second pair of adjacent struts of the first plurality of struts has a second separation distance therebetween, the second separation distance being different than the first separation distance.

19. The electric motor of claim 18, wherein, the first plurality of struts are non-uniformly circumferentially arranged about the motor axis such that a third pair of adjacent struts of the first plurality of struts has a third separation distance therebetween, the third separation distance being different than the first separation distance and the second separation distance.

20. The electric motor of claim 18 or 19, wherein, each strut of the first plurality of struts extends radially relative to the motor axis, and each strut of the first plurality of struts supports a respective plurality of branches that respectively support the first plurality of flux protrusions.

21. The electric motor of claim 18 or 19, wherein, the first plurality of laminates has a texture oriented radially relative to the motor axis, and each laminate stack of the first plurality of laminate stacks has a texture oriented parallel relative to the motor axis.

22. The electric motor of claim 18 or 19, wherein, a first laminate stack of the first plurality of laminate stacks has a different number of laminate layers than a second laminate stack of the first plurality of laminate stacks.

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