Three-dimensional magnetic flux motor and its manufacturing method

Abstract

A method for manufacturing a stator includes: preparing a yoke including a yoke manufactured by spray forming; preparing a teeth ring including a teeth ring manufactured by spray forming; dividing a portion of the teeth ring to form a plurality of teeth; arranging the plurality of teeth in a circular pattern with spaces between each other; fitting a coil onto each of the plurality of teeth, wherein the coil has two lead wires extending from the same side of the coil; placing the yoke on the plurality of teeth; placing a housing on the yoke; and connecting the coils to each other via the two lead wires.

Description

Related literature

[0001] This application claims priority to U.S. Provisional Application No. 63 / 447,951, filed February 24, 2023, and U.S. Provisional Application No. 63 / 529,406, filed July 28, 2023, which applications are incorporated herein by reference in their entireties. BACKGROUND

[0002] [Technical field] Example and non-limiting embodiments relate generally to electric motors, and more particularly to three-dimensional flux electric motors and methods for manufacturing such motors.

[0003] [Brief Description of the Prior Art] Electric motors are commonly used to provide translational or rotational motion to various moving elements in automated machinery. A commonly used electric motor consists of a fixed element (stator) and a rotating element (rotor). A magnet is mounted between the rotating element and the fixed element, or directly on the rotating element. A coil is wound on a soft iron core on the fixed element and placed in close proximity to the magnet.

[0004] When an electric motor is operated, a current flows through the coil, creating a magnetic field that acts on the magnet. When the magnetic field acts on the magnet, it pushes one side of the rotating element and pulls the other side of the rotating element, causing the rotating element to rotate relative to the fixed element. The efficiency of the rotation is based, at least in part, on the geometry of the magnetic components used and the properties of the materials used to manufacture the electric motor.

[0005] The following summary is exemplary only and is not intended to limit the scope of the claims.

[0006] According to one aspect, a method of manufacturing a stator includes: Providing a yoke, including a yoke manufactured by spray forming; Providing a tea sling, including a tea sling manufactured by spray forming; Dividing a portion of the teeth ring to form a plurality of teeth; arranging the plurality of teeth in a circular pattern with spaces between each other; fitting a coil onto each of the plurality of teeth, the coil having two leads extending from the same side of the coil; disposing the yoke on the plurality of teeth; placing a housing on said yoke; connecting the coils together at the two leads; Includes:

[0007] According to another aspect, a method of manufacturing a stator includes: Providing a yoke, including a yoke manufactured by spray forming; Providing a spray-formed tea sling; Dividing a portion of the teeth ring to form a plurality of teeth; arranging the plurality of teeth in a circular pattern with spaces between each other; fitting a coil onto each of the plurality of teeth; disposing the yoke on the plurality of teeth; placing the yoke in an encapsulation mold; connecting the coils to each other; injecting resin into the encapsulation mold; Includes:

[0008] According to another aspect, a method of assembling a stator / rotor assembly for a motor includes: providing a housing having a bearing sleeve, the bearing sleeve extending radially inward within the housing; Preparing a stator; The stator includes: A stator yoke manufactured by spray forming; a plurality of teeth spaced apart from one another on the stator yoke; a coil fitted to each of the plurality of teeth, the coil being connected to a coil fitted to an adjacent tooth; and the method further comprises: Mounting the stator within the housing and over the bearing sleeve; mounting a bearing adjacent to the bearing sleeve; Mounting a rotor having a rotor yoke and a plurality of magnets on a bearing sleeve; wherein mounting the rotor to the bearing sleeve comprises inserting the rotor into the housing in a stepwise and controlled insertion manner such that an air gap is formed between the stator and the rotor, the air gap being planar and perpendicular to an axis of rotation of the rotor relative to the stator.

[0009] According to another aspect, a stator for a three-dimensional flux electric motor comprises: stator yoke and; a plurality of teeth arranged on the stator yoke in a spaced-apart relationship; a coil disposed on each of the plurality of teeth; Each coil is connected to the coil of an adjacent tooth. Each of the plurality of teeth has a main portion and a top portion, the main portion has three side surfaces, the three side surfaces are connected by side edges, the three side surfaces each have a base edge and a top edge adjacent to the side edges, and the top portion is located above the top edge. In each of the plurality of teeth, the top portion has a protruding portion that protrudes outward from the top edge of the main portion. Each of the plurality of teeth allows magnetic flux to flow in at least the axial, radial, and circumferential directions.

[0010] According to another aspect, a three-dimensional flux electric motor is a housing having a bearing sleeve extending radially inward therein; at least one stator mounted within said housing and on said bearing sleeve; and wherein the at least one stator comprises: A stator yoke manufactured by spray forming; a plurality of spaced apart teeth disposed on the stator yoke; a coil disposed on each of the plurality of teeth; Equipped with Each of the coils is connected to the coil of an adjacent tooth; each of the plurality of teeth has a main portion and a top portion, the main portion has three side surfaces, the three side surfaces have a base and a top side, and the top side is located above the top side; the top portion has a protruding portion that protrudes outward from the top edge of the main portion; Each of the plurality of teeth allows magnetic flux to flow in an axial direction, a radial direction, and a circumferential direction; The three-dimensional flux electric motor further comprises at least one rotor mounted on the bearing sleeve, the at least one rotor comprising: a rotor yoke; a plurality of magnets on the rotor yoke; Equipped with The at least one stator and the at least one rotor are separated by an air gap. [Brief explanation of the drawings]

[0011] These and other features are described below with reference to the accompanying drawings.

[0012] [Figure 1] FIG. 1 is a perspective view showing an embodiment of a motor.

[0013] [Figure 2] FIG. 2 is a cross-sectional view of the exemplary motor of FIG. 1.

[0014] [Figure 3]1 is a perspective cross-sectional view of teeth on a yoke of an exemplary stator, showing magnetic flux flow in the axial, radial, and circumferential directions.

[0015] [Figure 4] FIG. 2 is a perspective view showing an example of a stator winding core and a coil assembly.

[0016] [Figure 5] 5A and 5D are perspective views showing examples of stator teeth.

[0017] FIG. 5B is a perspective view showing an example of a coil.

[0018] Figure 5C is a perspective view of an example coil, illustrating alignment structures at its ends.

[0019] [Figure 6] FIG. 10 is a flow diagram showing the manufacturing process of the yoke and teeth ring, and the manufacturing process of the yoke and teeth and rotor assembly.

[0020] [Figure 7A] FIG.

[0021] [Figure 7B] 7B is a perspective view and a plan view of a state in which teeth are attached to the positioning plate of FIG. 7A. FIG.

[0022] [Figure 7C] 7C is a perspective view of the teeth, coils, and positioning plate of FIG. 7B, with a yoke attached on top of the teeth and coils.

[0023] [Figure 8] FIG. 2 is a perspective view showing an example of a housing for a stator.

[0024] [Figure 9]1 is a schematic diagram showing an example of encapsulating a stator within a housing, and clearances between the coil and the housing, the coil and the teeth, and the yoke and the housing.

[0025] [Figure 10] FIG. 1 is a perspective view of a motor assembly with a stator disposed within a housing.

[0026] [Figure 11] FIG. 2 is a cross-sectional view illustrating an example of a bearing assembly used in a stator disclosed herein.

[0027] [Figure 12A] FIG. 1 is a plan view of the stator components and subassembly.

[0028] [Figure 12B] FIG. 10 is a perspective view of the coil-wound teeth and yoke on the fixed plate.

[0029] [Figure 12C] FIG. 1 is a perspective view of an example of an enclosed stator and bearing assembly after removal of the retaining plate;

[0030] [Figure 13] FIG. 2 is a diagram illustrating an example of a rotor.

[0031] [Figure 14] FIG. 2 is a perspective view showing an example of a stator in which coils are inserted or wound around each stator tooth.

[0032] [Figure 15] This is an example of a stator / rotor assembly in which one rotor is sandwiched between two stators.

[0033] [Figure 16] This is an example of a stator / rotor assembly using two rotors sandwiching a stator.

[0034] [Figure 17] FIG. 10 is a perspective view showing an example of an assembly process using a magnet.

[0035] [Figure 18] 1A and 1B are side and perspective views of an example spray-formed part having a geometry that includes tapered edges.

[0036] [Figure 19] FIG. 1 is a perspective view of an example of an apparatus used to spray form near-net-shape parts.

[0037] [Figure 20] 20A-20C are top views of the injector of FIG. 19 in various states.

[0038] [Figure 21] FIG. 1 is a schematic diagram illustrating an example of a multiple station configuration for spray forming.

[0039] [Figure 22] FIG. 1 is a perspective view showing an example of a disk-shaped part formed by spray forming.

[0040] [Figure 23] FIG. 1 is a schematic diagram of the disk arrangement showing the orientation of the disk mold assembly and spray gun.

[0041] [Figure 24] 10 is a schematic diagram illustrating a desirable change in the angle of incidence of a particle beam relative to a mold.

[0042] [Figure 25] 1 shows a graphical representation of build plate rotation direction and movement speed.

[0043] [Figure 26] FIG. 10 is a schematic diagram of the shape and placement of the air knife relative to the build plate.

[0044] [Figure 27] FIG. 10 is a cross-sectional view of the rounded edges of the mold plug.

[0045] [Figure 28] FIG. 1 is a process flow diagram of an example mold filling and removal process.

[0046] [Figure 29] FIG. 1 is a perspective view showing an example of a disk-shaped part having a void in the center.

[0047] [Figure 30] FIG. 1 is a perspective view illustrating an example of a mold assembly including a center mold portion.

[0048] [Figure 31] 1 is a schematic diagram of the angle of incidence of a particle beam at various points.

[0049] [Figure 32] FIG. 1 is a process flow diagram illustrating an example of a filling and unfilling process for a cylindrical near-net-shape part.

[0050] [Figure 33] 1A and 1B are perspective views of exemplary geometries of stepped edge disks having stepped center holes.

[0051] [Figure 34] FIG. 10 is a process diagram illustrating an example of a deposition process and near net shape part removal for a stepped feature disk part with a stepped center hole.

[0052] [Figure 35] 1 illustrates an exemplary geometry of a rectangular part and its tapered edges.

[0053] [Figure 36] FIG. 1 is a perspective view of a rectangular mold assembly having a multi-piece mold wall.

[0054] [Figure 37] 10A-10C are perspective views of a process for removing mold walls after filling of the mold cavity in a rectangular mold. Detailed explanation

[0055] The present invention describes an example electric motor and a method for manufacturing such a motor. It also describes an example method for manufacturing a stator for such a motor. In such a motor, the stator can be manufactured from an isotropic soft magnetic composite material produced by spray forming. Such materials readily pass magnetic flux in three independent spatial directions: axial, radial, and circumferential. Three-dimensional magnetic flux flow maximizes magnetic flux flow, enabling motor designs with higher power densities compared to traditional stator cores, which have two-dimensional magnetic flux flow. The spray forming process allows for the production of near-net-shape stator core shapes, thereby reducing the need for expensive machining. Such materials and methods are described, for example, in U.S. Patent Nos. 10,622,848, 10,170,946, and 9,887,598, and U.S. Patent Publication No. 2016 / 0197523, the entire disclosures of which are incorporated herein by reference. The method for producing soft magnetic composites in near-net shape by spray forming and the soft magnetic composites can be used in the manufacture of electric motors. For example, U.S. Patent No. 9,205,488 discloses soft magnetic materials produced by a spray forming process, and U.S. Patent Publication No. 2013 / 0000860 describes a spray forming process based on layered particle deposition.

[0056] 1 and 2, an example motor is shown generally at 100. Motor 100 is a hybrid field motor (HEM) and includes a stator 110 and a rotor 120. Stator 110 and rotor 120 are assembled such that the torque-generating air gap therebetween is substantially planar and perpendicular to axis of rotation 130. The direction of magnetic flux flow in the air gap can be considered to be parallel to axis of rotation 130.

[0057] FIG. 2 shows a cross section of the motor 100. The stator 110 includes coils 124, stator teeth 126, and a backing ring or yoke 128. These may be disposed within a housing 122. A bearing sleeve 131 extends within the housing 122. Removable and replaceable motor bearings are housed within the bearing sleeve 131, facilitating motor maintenance. In particular, a radial bearing 132 and a thrust bearing 134 are mounted within the bearing sleeve 131 to facilitate rotation of the rotor 120 relative to the stator 110. The housing 122 also defines a space 136 for routing interconnecting wires.

[0058] Referring to FIG. 3, magnetic flux flow within the stator 110 is primarily axial, but also has radial and circumferential components. Each stator tooth 126 has a main portion 146 attached to a yoke 128 and a tooth overhang 150 located on top of the main portion 146. In FIG. 3, the stator teeth 126 are depicted without the coils 124. The stator teeth 126 are designed to ensure axial, radial, and circumferential flux flow. The radial and circumferential flux flow is facilitated by the tooth overhangs 150 at the ends of the main portion 146. These radial and circumferential components increase the overall effective air gap area.

[0059] Referring to FIG. 4, an example of a stator winding core and coil assembly of the stator 110 is shown. The stator winding core and coil assembly includes a stator yoke 128, a plurality of teeth (12 teeth 126 are shown in the specific example of FIG. 4), and a plurality of formed coils 124 (12 formed coils are shown in the specific example of FIG. 4). One tooth 126 is shown without a coil 124 attached. The yoke 128 is formed with an alignment feature 127 for aligning the yoke 128 within the housing 122. A space 129 defined between the coils 124 is used as a connection for solder joints. A thermistor valve 135 for detecting temperature may be disposed in the stator yoke 128.

[0060] 5A, 5B, 5C, and 5D, examples of a single stator tooth 126, a single coil 124, and a yoke 128 (or backing ring) are shown. As shown in FIG. 5C, the yoke 128 is a planar disk having a central hole 140 and alignment structures 127. The alignment structures 127 are structures for positioning the yoke 128 relative to the housing 122 and the stator teeth 126.

[0061] As shown in FIGS. 5A and 5D, each stator tooth 126 has a main portion 146 with an outer corner 148 and a tooth overhang 150 that extends over and extends from the main portion 146. The outer corners 148 are chamfered or rounded. The inner corners of the stator teeth 126 between the tooth overhang 150 and the main portion 146 may have fillets 152 (FIG. 5D). The fillets 152 at the inner corners minimize stress concentrations. The chamfered or rounded outer corners correspond to the inner radius of the coils 124. The coils 124 are positioned over the main portions 146 of the teeth 126. As shown in FIG. 5B, coil leads 137 extend from the bottom end of each coil 124.

[0062] FIG. 6 illustrates an example process for manufacturing the yoke 128 and teeth ring 138. The teeth 126 are formed from the yoke 128 and teeth ring 138. FIG. 6 also illustrates an example process for manufacturing the assembly of the yoke 128 and teeth 126 with the rotor 120 to form the motor 100. As shown in FIG. 6, the stator yoke 128 is spray formed as an axisymmetric disk with a central hole 140 and can be manufactured to a near-net size. The teeth ring 138 is also spray formed into an axisymmetric disk shape with a stepped outer periphery and a stepped central hole and can be manufactured to a near-net size. The teeth ring 138 is then cut into a plurality of teeth 126 (12 in this particular example).

[0063] The coils 124 may be pre-formed and secured to the teeth 126. Alternatively, the coils 124 may be formed by winding wire around the teeth. If the coils 124 are pre-formed, they are compressed to maximize copper density. Each coil 124 may have two leads 137 extending from the bottom edge in a plane parallel to the air gap. The coils 124 are pre-formed or pre-wound so that the leads 137 of each coil 124 exit from the side facing the yoke 128. The coils 124 may be connected in a wye or delta configuration, and in parallel or series. The connections between the coils 124 are routed through the space around the yoke 128, with solder connections accommodated in the spaces between adjacent coils 124. The teeth 126 with their corresponding coils 124 are assembled to the yoke 128.

[0064] To minimize the overall stator volume, the interconnection wiring may be routed around the stator 110 within the annular space defined by the outer surface of the yoke 128, the bottom surfaces of the coils 124, and the inner surface of the housing 122. The space between adjacent coils 124 at the outer diameter can be used to place joints (e.g., solder joints) between the interconnection wiring. Alternatively, the coils 124 can be wound together without joints. The space between the coils can also be used to accommodate bosses on the housing 122. The bosses may have threaded mounting holes.

[0065] Referring to Fig. 7A, a fixing plate 190 is shown that can be used to facilitate the positioning of teeth 126. As shown in Fig. 7B, features 194 are disposed on fixing plate 190 between teeth 126. As shown in Fig. 7C, yoke 128 is attached to teeth 126 on the opposite side of fixing plate 190. At this time, coil lead wire 137 runs along the side of yoke 128.

[0066] 8, there is shown the housing 122. A fixing plate 190 mates with the housing 122 to form an enclosure which is filled with an epoxy-based potting material and allowed to cure.

[0067] Housing 122 includes an outer wall 123, an inner wall 125, and an end face 133. When the stator is assembled, inner wall 125 and outer wall 123 are in close proximity to the coil end turns, allowing for a short heat transfer path from coil 124 to housing 122 at both the inner and outer radii. End face 133 may have mounting features 141 in the form of threaded holes. Housing 122 includes holes 139 for exiting leads 137. Leads 137 may be present on either the end face, the outer face, or the inner face.

[0068] The stator assembly, consisting of a yoke 128, a number of teeth 126 each with a coil 124, and interconnecting wires, is encapsulated in an epoxy-based potting compound that prevents the coils from vibrating during motor operation, provides desirable structural integrity to the stator assembly, and facilitates thermal management of the motor.

[0069] 9, an example is shown in which the stator assembly, including stator teeth 126, yoke 128, coils 124, and interconnecting wires, is encapsulated with an epoxy-based potting material. The encapsulant prevents vibration of the coils during motor operation, provides necessary structural integrity to the stator assembly, and facilitates thermal management of motor 100. To ensure sufficient adhesion between coils 124 and stator teeth 126, between coils 124 and housing 122, between coils 124 and yoke 128, and between yoke 128 and housing 122, the design incorporates tolerances to ensure epoxy filler layers between surfaces.

[0070] After the potting material has cured, the retaining plate is removed. The housing 122 remains adhered to the stator assembly. Figure 10 shows the assembled motor 100 with the stator 110 mounted within the housing 122 and the rotor 120 extending from the opposite end of the housing 122.

[0071] The stator assembly may be enclosed without the housing 122 and then assembled to the housing 122 .

[0072] Referring to FIG. 11 , an example of a stator bearing sleeve assembly is shown at 160. This motor is characterized by a strong axial attractive force between the rotor 120 and the stator 110. This axial force is unstable in the sense that it increases as the gap decreases. The axial attractive force also generates an unsettling moment between the rotor 120 and the stator 110 due to the difference in the attractive forces from the rotor to the stator on either side of the tilt axis. The axial load is supported by a thrust bearing 134 located in a cylindrical space within the stator 110. A radial bearing 132 may also be provided to support the radial load. The magnetic attractive force acts as a constant preload on the thrust bearing 134. The thrust bearing 134, in combination with the radial bearing 132, provides a restoring moment and stabilizing moment stiffness between the rotor 120 and the stator 110. As a result, the rotor-stator-bearing assembly can operate as a self-contained motor without the need for an external bearing set. The axial thrust bearing 134 has an axial load capacity of 1800 N to withstand the internal loads and a bidirectional axial stiffness of 100 kN / mm. Additionally, in combination with the radial bearing 132, the thrust bearing 134 also provides a stabilizing moment stiffness estimated at 1.75 Nm / milli-rad, sufficient to counter the destabilizing moment (estimated at 0.2 Nm / milli-rad) exerted on the rotor 120 by magnetic attraction.

[0073] As a result, the rotor-stator-bearing assembly can operate as a self-contained motor without the need for an external bearing set.

[0074] Figures 12A, 12B, and 12C show the stator at various stages of manufacture. Figure 12A shows the unassembled stator to illustrate the various elements of the stator (housing 122, yoke 128, coil assembly 124, and teeth assembly 126 on fixture plate 190). Figure 12B shows the stator assembly including coil 124, interconnecting wires, and yoke 128 on fixture plate 190. Figure 12C shows the stator and bearing assembly encapsulated in potting material after the positioning fixture plate has been removed.

[0075] 13A and 13B, rotor 120 may have rotor yoke 200 and magnets 202. Rotor yoke 200 may have ribs 204 for arranging the magnets in a circular pattern and lips to provide the centripetal force necessary to hold the magnets. In single-sided and dual-rotor designs, the magnets are surface-mounted to rotor 120. In dual-stator designs, rotor yoke 200 is not present. The magnets are held in place by a non-magnetic structure.

[0076] Referring to FIGS. 15 and 16, alternative configurations of stator / rotor assemblies for motors are shown. As shown in FIG. 15, the motor may include a dual-stator embodiment 300 in which a first stator 302 and a second stator 304 sandwich a central rotor 306. A motor using the dual-stator embodiment 300 can be manufactured using the exemplary procedures described herein. As shown in FIG. 16, the motor may include a dual-rotor embodiment 400 in which a single stator 402 is sandwiched between a first rotor 404 and a second rotor 406. A motor using the dual-rotor embodiment 400 can also be manufactured using the exemplary procedures described herein. The exemplary dual-stator embodiment 300 shown in FIG. 15 and the exemplary dual-rotor embodiment 400 shown in FIG. 16 can be manufactured without internal axial forces and without the use of thrust bearings (e.g., using only two radial bearings).

[0077] As an extension of the present invention, in the example shown in FIG. 2, the stator housing may be potted in place and non-removable. However, the stator could also be manufactured with a removable housing enclosure. A dual stator embodiment, in which two stators sandwich a central rotor (FIG. 15), can also be utilized and manufactured using the above procedure. Additionally, a dual rotor embodiment, in which a single stator is sandwiched (FIG. 16), can also be utilized and manufactured using the above procedure. The embodiments shown in FIGS. 15 and 16 can be fabricated using only two radial bearings, for example, and no thrust bearings, because the internal axial forces are not significant.

[0078] An example of a method for manufacturing the motor 100 can be summarized as follows.

[0079] Stator manufacturing 1) The stator yoke 128 and the teeth ring 138 are formed near net. 2) The teeth ring 138 is cut into a number of teeth (12 teeth in this example). The yoke 128 is used as is. 3) Wrap the main portion of each stator tooth 126 in porous electrical insulating tape to prevent direct contact with the coil 124. 4) Using the locating fixture plate 190 shown in Figure 7A, the stator teeth 126 are precisely positioned in a circular pattern as shown in Figure 7B. The locating fixture plate 190 has features 194 that precisely space the stator teeth 126. As shown in Figure 7B, the inlet ports 192 of the locating fixture plate 190 are aligned with the spaces between adjacent stator teeth 126 to allow the epoxy to flow easily. 5) Each coil is coated with a thin layer of epoxy to cover any surface insulation defects. 6) As depicted in FIG. 14, wind or fit a coil onto each stator tooth 126 with the leads 137 pointing away from the positioning plate 190. 7) Place the yoke 128 on the stator teeth 126 as depicted in Figure 7C. The yoke 128 has locating features such as flats or notches to accurately position the yoke 128 relative to the housing 122. 12B, the coils are connected in a wye or delta configuration, and in series or parallel, as specified by the motor design. The interconnecting wires are electrically insulated and routed around the yoke 128 within the annular space defined by the outer surface of the yoke 128, the surface of the coil 124, and the housing 122. 9) A temperature detection device such as a thermistor valve 135 may be mounted between adjacent coils. 10) Attach the housing 122 to the assembly. The lead wire 137 is passed through the lead wire exit hole in the housing 122. 11) To allow for tolerances, a gap may exist between the yoke 128 and the stator housing 122. As shown in Figure 17, during assembly, a magnet 196 may be temporarily placed under the fixed plate 190 to generate an attractive force on the yoke 128, bringing the yoke 128 into contact with the stator teeth 126. 12) Referring to Figure 12A, there is shown a housing 122, a yoke 128, a coil assembly, and a teeth assembly mounted on a positioning fixture plate 190. The housing 122 and the positioning fixture plate 190 can together form an encapsulated housing. The positioning fixture plate 190 has one or more openings that function as a resin inlet. The housing 122 has one or more openings that function as a resin outlet. 13) The housing 122 may be replaced with a special removable encapsulation mold, in which case the mold is sprayed with a release agent to form a non-stick layer. 14) Fix the stator assembly from below with the positioning fixing plate 190, inject resin from the inlet port, and continue injecting the resin to rise against gravity until the resin flows out from the outlet port of the housing 122 at the top. 15) The resin is heated to a temperature above the glass transition temperature or to a set temperature to reduce the viscosity of the resin and allow it to flow at a low viscosity, so that it can fill the gaps between the teeth, coil, yoke 128, and housing 122. 16) The stator assembly including the coils, interconnecting wires, and yoke 128 on a positioning fixture plate 190 is shown in Figure 12B. An example of a completed encapsulated stator is shown in Figure 12C.

[0080] Assembly of rotor 120 1) A plurality of magnets 202 are mounted on the surface of the rotor yoke 200. 2) A special alignment fixture or rib 204 may be used to ensure equal spacing between magnets 202.

[0081] 1 and 2, the final assembly of the motor 100 will be described as follows. 1) Insert the bearing sleeve 131 from the lead wire side. 2) Assemble the axial thrust bearing 134 into the bearing sleeve 131 from the air gap side. 3) The radial bearing 132 is assembled from the lead wire end of the stator 110. 4) Insert the rotor 120 into the stator 110 from the air gap side. 5) Insert the retaining clip into the end of the lead wire. 6) The rotor 120 is inserted using an insertion device that allows for controlled, gradual insertion of the rotor 120 into the stator 110. This is because the attractive force between the stator 110 and the rotor 120 increases with the insertion depth. Once insertion is complete, the rotor 120 is removed from the insertion device.

[0082] Although the above examples and methods use near-net-shape spray-formed parts, the parts may be obtained by machining (or other suitable processes) bulk spray-formed material, or may be manufactured from other suitable soft magnetic composite materials using suitable manufacturing methods.

[0083] To manufacture near-net-shape components, particularly yokes and teeth rings, techniques and equipment are used that allow for the spray deposition of isotropic soft magnetic composite materials to produce near-net-shape components. These composites have a dense matrix of multiple ferromagnetic domains separated by electrically insulating boundaries. Such soft magnetic composites can be used to manufacture electric motors that utilize three-dimensional magnetic flux flow, known as hybrid field motors. The term "near-net" means that only the sprayed surface is post-processed. The surface defined by the mold walls and build plate does not require post-processing. The amount of material removed by post-processing is approximately 1 millimeter (mm) or less. The material removal rate is lower for thicker parts. Manufacturing various shapes of stators and stator components near-net-shape eliminates the need for expensive, complex, and time-consuming post-processing. Manufacturing various shapes of stators and stator components, such as yokes, near-net-shape eliminates the need for expensive, complex, and time-consuming post-processing.

[0084] Spray forming (also known as spray deposition) is a process for producing soft magnetic composites by depositing particles onto a substrate plate at high temperature and high velocity. When spray forming is performed directly on a build plate 10, the deposited material 14 forms a material geometry with tapered edges 12, as shown in Figures 18A and 18B, which may require post-processing to achieve the final desired geometry. To avoid costly and time-consuming post-processing, it is desirable to produce the desired shape near net shape. Examples of desired shapes include, but are not limited to, disks, rings, and rectangular parts.

[0085] The embodiment described here uses a mold to realize the production of spray-formed parts (stator parts such as yokes, teeth rings, and housings) in near-net shapes. 1) The spray-deposited material completely fills the mold cavity. 100% filling of the mold cavity (no voids) is desired. 2) The mold design should have at least one open surface through which material can be spray deposited. 3) After deposition, the filled material can be removed in a manner that allows the mold to be removed from the mold in a reusable state.

[0086] The following aspects of near-net-shape forming using molds are then explained: (a) Mold geometry design; (b) Selection of mold material; (c) Deposition of material into the mold cavity; (d) Methods of removal from the mold, separation, and recycling.

[0087] The embodiments described herein actually involve the deposition of a powder having a core-shell structure using a High Velocity Air Fuel (HVAF) thermal spray gun. Such powder may be, for example, iron or a mild iron alloy (such as an iron-based alloy, an iron-cobalt alloy, a nickel-iron alloy, a silicon-iron alloy, an iron-aluminide, a ferritic stainless steel, or a similar alloy), coated with an electrically insulating material (preferably at least one ceramic-based material, such as alumina, magnesia, zirconia, or the like). The methods described herein are also applicable to other types of powders and can be used in combination with other types of delivery systems. The deposition process includes: (a) Repeated scanning of the particle beam incident point on the deposit, also called a spray pass. (b) Variation of the particle beam tilt angle relative to the deposit. (c) Measuring and monitoring deposit thickness.

[0088] Referring to FIG. 19 , an example of an apparatus for depositing such materials is shown at 1900, hereafter referred to as the “spray apparatus 1900.” The spray apparatus 1900 is used to create axisymmetric near-net-shape parts. The spray apparatus 1900 includes a spray gun 1901 having a nozzle, a build plate to which a mold 1902 is attached, and a cooling device 1903. The build plate and mold 1902 are mounted on a stage 1911 and are rotatable about a rotation axis Φ. At least one of the spray gun 1901 and the mold 1902 is movable about three independent axes. The spray gun 1901 deposits metal powder onto the mold 1902. The cooling device 1903 is disposed in a fixed position relative to the mold 1902. The mold 1902 is moved by driving the X-slide 1905 using the X-direction motor 1907 while simultaneously rotating the mold 1902 around the Φ-axis using motor 1910. A solid material is formed by repeatedly spraying material from the spray gun 1901 until the desired thickness is reached. After each pass, the Y-direction motor 1908 drives the mold 1902 on the Y-slide 1904 to move in the Y-direction, thereby maintaining a constant distance from the spray gun 1901 to the interface of the deposited material. To spray the corners of the mold cavity, the θ-axis can be rotated using the θ-direction motor 1909. During the deposition process, the positions of the X-stage and Y-stage are adjusted so that the particle beam's point of incidence coincides with the axis of rotation (θ-axis) on the part surface.

[0089] The movement and position of the spray gun 1901 and / or mold 1902 may be controlled by a controller having at least one processor and at least one non-volatile memory that stores instructions that, when executed by the processor, cause operations that result in movement of the spray gun 1901 and / or mold 1902. Movement of either the spray gun 1901 or mold 1902, or both, may be accomplished by controlled operation of a motor. The cooling device 1903 may also be controlled using the processor, memory, and instructions.

[0090] Figures 20A, 20B, 20C, and 20D show top views of the spraying apparatus 1900 at different θ positions. The particle beam's point of incidence on the part surface is on the rotation axis of the θ stage. To fill corners without creating voids, the build plate and mold 1902 rotate about the θ axis, as shown in Figure 20B. By moving the X position, as shown in Figure 20C, new positions of the mold 1902 are continually exposed to the particle beam. If the mold corners are not being filled, the θ rotation is set to 0 degrees (perpendicular to the spray path) to maximize material adhesion. Throughout the spraying operation, the build plate rotates about the Φ axis (1910) to maintain a uniform, axisymmetric shape. This rotation also ensures cooling uniformity using the air cooling fixture 1903, whose position remains constant regardless of X, Y, or θ rotation. The thickness of the deposited material can be measured with a distance sensor 2101, which is zeroed on the build plate surface. The Y-slide plate 1904 is moved until the build plate and mold 1902 are facing the distance sensor (set at 90 degrees as shown). After the thickness measurement, the device returns to the initial position as shown in Figure 20A for the next material deposition process.

[0091] Referring to FIG. 21, a multi-station configuration is shown. A single spray gun 1901 can produce multiple near-net-shape parts using parallel stations. A first station 3101 is arranged in parallel with a second station 3102. The number of stations can be increased to three or more. The spray gun 1901 moves from station 3101 to station 3102, sequentially filling the mold 1902. A computer-based control monitors and adjusts the temperature, material thickness, motion trajectory, and running conditions to ensure repeatability and quality metrics. The computer-based control is shown at 3104 and can include at least one processor and at least one non-volatile memory. The memory stores instructions that, when executed by the at least one processor, perform the spray and movement operations. The movement operations can be performed by controlling a motor M.

[0092] Alternatively, the mold 1902 can rotate about a fixed axis and the spray gun 1901 can move to achieve the desired spray beam movement and tilt. One example is to mount the spray gun 1901 on a multi-axis robot. This robot can simultaneously scan and tilt, and also move toward or away from the mold 1902. In a multi-station configuration, the robot can also move between stations.

[0093] The method for forming near net shape parts also involves mold design and mold filling, which are also described below. Figures 22, 29, 33, 35A, and 35B show examples of final near net shape parts using the methods described herein. [Mold design]

[0094] Mold design includes designing the mold geometry, selecting the mold material, and selecting the optimum mold surface characteristics. (a) Mold Geometry: A mold is an assembly consisting of two basic elements: a mold base plate and mold sidewall components. The base plate interfaces with the particles delivered from the spray deposition system. The mold sidewalls define the contours of the desired shape. For example, to produce a cylindrical ring-shaped part, a mold consisting of a mold base plate and an outer wall may be used. In some embodiments, an internal plug may be used (see Figures 30, 31, 32, and 34). The volume enclosed by the outer wall, inner wall, and mold base plate surfaces represents the mold volume to be filled. The wedge effect of high-velocity impacting particles creates compressive stress in the spray-molded material. This compressive stress generates positive contact pressure on the mold wall. If the mold wall is made of a low-strength material such as aluminum, it must be thick enough to withstand the compressive stress. (b) Mold Surface Characteristics: To achieve 100% filling of the mold volume, mold surfaces must meet two requirements. (i) The mating surfaces must be highly flat to avoid gaps between the surfaces. Gaps between the mating surfaces due to surface roughness, impurities, or scratches can create voids in the mold filling space. (ii) The second requirement is to avoid rounded or chamfered edges. The incident particle beam cannot reach the space under rounded or beveled areas, causing voids. Generally, mold surfaces that come into contact with each other are machined to a surface flatness of 0.005 inches (in.) or better. During mold manufacturing, processing methods are employed to avoid rounded or chamfered edges. Mold surfaces may be grit-blasted. The desired adhesion strength between the material and the mold surface can be achieved by grit-blasting. (c) Mold Material: The material selection for the build plate and sidewalls is based on several criteria. The mold material is selected as follows: the build plate components are low carbon steel and the mold exterior is aluminum. The low carbon steel material is selected due to the limited bond strength between the deposit and the steel. Build plate: One of the factors in selecting a material for the build plate is the adhesive strength between the build plate and the deposit. A low adhesive strength is desirable to facilitate easy release after deposition. For this reason, build plates are made of high-strength steel. On the other hand, if the adhesive strength is too low, premature delamination occurs. Adhesion strength is proportional to the degree to which high-velocity particles penetrate into the mold surface under high pressure and the temperature of the particles. To limit penetration, the surface of the build plate that comes into direct contact with the particles is made of a high-strength material such as steel. On the other hand, grit-blasting the build plate to increase the surface roughness improves adhesive strength. Mold walls: In contrast to the build plate, the impacting particles hit the mold wall at a shallow angle (Figure 24) and do not have enough momentum to penetrate the wall surface. Therefore, the mold walls can be made of a low-strength material, such as aluminum, without the risk of particles penetrating the mold. The advantage of using aluminum is the large difference in thermal expansion coefficient between aluminum and the spray material. One method of mold wall release is to use the difference in thermal expansion coefficient to reduce the contact pressure between the mold wall and the sprayed material. For this reason, the mold wall material must have a higher thermal expansion coefficient than the sprayed material. Aluminum has a higher thermal expansion coefficient than iron-based materials, making it ideal as a mold wall material. [Axisymmetric Near Net Shape Disc] [Deposition in the mold]

[0095] The following is an overview of the near-net-shape deposition of a spray-formed disk-shaped part 4000 suitable for forming parts such as stators and teeth rings. Figure 22 shows the geometry of the disk part in detail. The disk part has an upper surface and an opposite lower surface. The upper surface is 4101 and the lower surface is 4102, with a vertical wall 4103 defining a cylindrical outer diameter. The upper and lower surfaces 4101, 4102 are substantially flat and parallel. Other part shapes are possible.

[0096] A disk-shaped part 4000 cannot be produced by jetting directly onto the build plate surface. The deposited material forms a beveled edge whenever deposition stops. Examples of beveled edges formed on a build plate are shown in Figures 18A and 18B.

[0097] To produce a disk shape, a mold consisting of a build plate and outer wall is assembled into a rotating fixture. A powder spray is directed at the open face of the mold. The movement of at least the spray gun 1901 and the mold can be controlled using a controller having at least one processor and non-volatile memory that stores instructions that, when executed by the processor, control the operation of the spray gun 1901 and the movement (and cooling) of the mold. A schematic diagram of the disk setup is shown in Figure 23.

[0098] As shown in Figure 23, an example mold 1902 has a build plate 5101 and an outer mold wall 5102. A powder jet beam from a spray gun 1901 deposits material into the mold cavity. To achieve complete filling, a variable trajectory is used, as shown in Figure 24.

[0099] The mold assembly or mold 1902 is comprised of multiple components. A near-net-shape disc mold uses two components. The first component, the build plate 5101, is made of low-carbon steel and is fastened to an aluminum mold wall component (see Figure 23). In one example, these two components are fastened together with two or more bolts and nuts to provide a uniform clamping force around the mold wall. These bolts and nuts are uniformly spaced radially and provide axial clamping force. The torque of each fastener is set to approximately 30 lb-ft (pound-feet). The aluminum mold wall is thick enough to prevent material deformation when compressive stresses from spray forming are applied to the mold wall.

[0100] Prior to assembly of the mold assembly, the parts are abrasive blasted while clamped, using, for example, aluminum oxide abrasive with a mesh size of 40-140, to aid in adhesion. The mold part material is selected to allow for removal of the parts from the mold 1902, as described in more detail in the "Removal from Mold" section.

[0101] The choice of steel material for the build plate components can pose adhesion challenges. To overcome low bond strength between the steel build plate and the deposit, the first layer can be deposited without cooling to improve adhesion. Up to 10 no-cool bond passes can be used, with five being the most common. The no-cool bond pass can be immediately followed by a series of passes with a tapered temperature profile to deposit material until a continuous process setpoint is reached. In this example, a standard temperature control regime drives the process as the temperature tapers down to approximately 190°C.

[0102] Referring to FIG. 24, the operation sequence for producing the disk-shaped part 4000 may be divided into two components: (1) operation of the spray gun 1901; and (2) operation of the mold 1902. The operation of the spray gun 1901 may employ a six-axis robot controlled by a controller having at least one processor and at least one non-volatile memory that stores instructions that, when executed by the processor, cause the robot to operate. The robot moves in a linear path parallel to the build plate 5101, allowing for a variable spray angle relative to the build plate 5101, for example, up to 45 degrees. The angle can be set to any orientation relative to the build plate 5101, with 0 degrees being a spray perpendicular to the build plate 5101. The movement of the mold 1902 may also be controlled by the controller, for example, by controlling and operating a motor. The spray angles used for vertical walls are shown in FIG. 24.

[0103] As shown in Figure 24, the desired variation in the particle beam angle relative to the mold 1902 is shown to fill the interior corners of the mold 1902. The spray deposition process utilizes precise control of the particle beam's point of incidence ("beam spot position") and the beam's orientation relative to the mold ("beam orientation"). Precise control of the beam spot position and beam direction can be achieved by mounting the spray gun 1901 on a servo-controlled six-axis robotic arm, or by fixing the spray gun's position and moving / rotating the mold assembly as described for the apparatus 100 in Figure 19. Additionally, the mold 1902 can be mounted on a rotating platform. The beam orientation / angle is 2-20 degrees (typically 5-10 degrees) near the mold wall and 0 degrees in areas away from the mold wall. When fabricating axisymmetric parts (e.g., parts with cylindrical surfaces), the mold 1902 is mounted on a platform that rotates about the axis of symmetry, and the beam spot is moved along a linear radial or near-radial path.

[0104] For walls parallel to the path of travel of the spray gun 1901, an angle of 5-10 degrees may be used. This angle helps reduce the robot travel distance or mold travel distance and also provides the best adhesion of the sprayed material to the build plate, which is greatest at a spray angle of 0 degrees. The spray gun 1901 (and other spray devices disclosed herein) can be controlled by a controller having at least one processor and at least one non-volatile memory that stores instructions that, when executed by the processor, cause the device to perform various operations.

[0105] For circular parts with axisymmetrical symmetry, such as disks, the mold assembly or mold 1902 rotates continuously about the axis of symmetry. The robot synchronously moves the spray gun 1901 in a linear path to completely deposit material within the mold cavity. The rotational and linear rotational speeds of the mold assembly or mold 1902 are coupled so that the beam spot velocity is fixed relative to the build plate surface, e.g., 600 mm / s (millimeters per second). Additionally or alternatively, the mold 1902 may be moved independently or synchronously with the spray gun 1901, such as the spray device 1900.

[0106] Figure 25 shows the build plate rotation direction and translation speeds used. To optimize the temperature of the deposit, the beam spot speed can be varied by ±50% during the filling operation. Figure 25 shows an example of the relative scan speed of the particle beam point of incidence and the mold center to produce the disk-shaped part 6000 shown in Figure 29. In this example, the disk is rotating at 300 rpm (revolutions per minute), and the desired relative surface speed is 600 mm / s.

[0107] In either embodiment, the temperature of the deposition material can be controlled using a computer algorithm that initiates each deposition pass when a predetermined temperature is reached. For example, a non-contact infrared thermometer can be used to measure the temperature. To maintain a constant mold temperature throughout the deposition process, the mold assembly or mold 1902 can be preheated, for example, to 300-325°C, before the start of the deposition operation. During the material deposition process, the temperature can continually increase due to hot particles being added to the material and the combustion reaction flame located directly above the mold assembly during deposition. Each deposition pass begins when the mold assembly has cooled to, for example, 190°C, to ensure uniformity between passes. To control the maximum temperature of the mold assembly or mold 1902, the robot movement speed can be adjusted to control the deposition time for each pass. The maximum temperature setpoint can be set, for example, to 350-400°C.

[0108] There are several processes for cooling the mold assembly and deposit. Two of these processes are described below. The first process uses compressed air supplied by the spray gun 1901 to cool the mold assembly. The spray controller stops the powder flow and shuts off the fuel source. The compressed air source remains on, and the robot moves the spray gun 1901 along the same motion path to cool the assembly. However, this approach can add significant time to the completed part. The second process uses a secondary cooling source. A compressed air jet, either from a point source or a linear air knife edge, is directed at the mold assembly. The amount of cooling can be controlled by adjusting the opening cross-sectional area, the air supply pressure, and the distance between the air jet and the mold assembly. There are many effective cooling configurations. As an example, the following settings are used: 40 psi (pounds per square inch) suction pressure, a 10 foot by 0.5 inch hose, and a 3 inch air knife with a 0.006 inch opening, positioned 0.5 inches below the mold centerline and approximately 2 inches from the face of the build plate. The geometry and placement relative to the build plate is shown in Figure 26.

[0109] FIG. 26 illustrates air knife cooling of the deposit and build plate 5101. This diagram shows the location of the air knife 8000 used to cool the deposit forming the disk-shaped part 6000. During the spray forming process, the temperature of the mold assembly or mold 1902 and deposit increases to 450°C. As the temperature increases, the aluminum mold walls 5102 tend to expand more than the deposit. To prevent the material from separating from the mold 1902 during the deposition process, it is desirable to maintain a positive surface contact pressure on the mold walls 5102. To ensure sufficient contact pressure, the mold 1902 is preheated before starting material deposition. Additionally, the mold walls 5102 are bolted to the build plate 5101 with sufficient clamping force.

[0110] Squareness of the edges and mating surfaces is important to achieve near-net-shape parts without missing material or voids. The mating surfaces connecting the build plate and outer mold wall must be less than 0.005 inches flat. Surface roughness or imperfections can create areas where the two surfaces do not meet, potentially leading to void formation. The mating surfaces must remain smooth (less than 0.005 inches roughness) even after grit blasting. Therefore, it is recommended that the mold assembly be clamped prior to any process. In addition to flatness, edges between parts of the mold assembly should be sharp. Rounded or beveled edges create spaces below the mold that are inaccessible during the deposition process. If rounded or beveled areas are present, the material may not be able to properly fill the spaces. This can result in voids that the spray material cannot fill.

[0111] Figure 27 shows an example of rounded or beveled edges that can cause voids. As shown, the outer mold wall 5102 depicts sharp edges and an ideal interface, which is desirable for a near-net shape without voids. The center mold part 5103, which is not used for the disk part, shows a radius 5105, which can cause imperfections in the spray-formed material during material deposition. When rounded or beveled edges are present, voids can occur in the material. Broken corners or edges can also cause voids. Square or sharp edges are used to achieve the desired spray-formed part. The exact radius that is acceptable is unknown.

[0112] The thickness of the deposition can be controlled in two different ways. First, a sacrificial material can be jetted to calibrate the deposition rate or material growth per pass. From the deposition rate, the number of passes required can be calculated. Second, a distance or displacement sensor is used that is zeroed on the build plate surface before deposition and the total deposition thickness is measured periodically. [Removal from mold]

[0113] Referring now to FIG. 28, once material deposition is complete in a multi-pass operation using the trajectory shown in FIG. 24, the material is removed from the mold 1902. Prior to deposition, the mold assembly, consisting of the build plate 5101 and mold walls 5102, is preheated to promote material adhesion and prevent thermal shock. Once the desired part thickness is achieved, the mold walls 5102 and build plate 5101 are removed from the spray apparatus 1900. The build plate 5101 is separated from the mold walls 5102. The part is heated and ejected from inside the mold walls 5102. Due to the difference in thermal expansion rates of the two materials, the mold walls 5102 expand more than the part due to the heat. After heating, the part can be removed from the mold 1902.

[0114] To remove a build plate part from the mold assembly, a small mechanical force can be applied between the interface of the build plate 5101 and the mold wall 5102. This allows the build plate 5101 to be removed while leaving other parts intact. If the adhesive strength of the jetted material to the build plate 5101 is stronger than the strength of the deposited material, separation will occur within the deposited material rather than at the interface.

[0115] When the build plate 5101 is removed, the mold wall 5102 separates from the spray-formed material. When material is deposited by thermal spraying, the dense packing of particles during deposition creates compressive stress in the material. This stress holds the material tightly within the aluminum mold. While it may be possible to apply a large force to remove the deposited material from the mold 1902 with a press, this may cause the material to fracture before the part leaves the mold 1902.

[0116] Alternatively, the difference in the thermal expansion coefficients between the material of the mold walls 5102 and the material of the deposit can be utilized. Aluminum is a common choice for the mold walls 5102, as its thermal expansion coefficient is approximately twice that of the material of the deposit (23.3 μm / mC vs. 12.0 μm / mC, respectively). When the mold walls 5102 and deposit are heated to 600°C, the aluminum expands more than the deposit. While the mold 1902 is expanding, the disk-shaped deposit (e.g., disk-shaped portion 6000) can be directly removed with little force, as shown in FIG. 28.

[0117] Tight tolerance control of mold dimensions allows for near-net-shape dimensional tolerances of 0.005 inches or less. Even lower dimensional tolerances can be achieved by making the mold 1902 smaller to account for expansion that occurs as the mold temperature increases during the deposition process. Because the core-shell material releases from the mold surface with little or no residual deposit, the mold 1902 can be used repeatedly to produce identically shaped parts. [Axisymmetric near-net-shape disk with a central hole]

[0118] An extension of the near-net disk shape is the same cylindrical shape, but incorporating a cylindrical void or an angular ring. FIG. 29 shows a preferred shape for a part 6000, such as a motor component, with a ring-shaped void. The spray-formed motor component 6000 is a spray-formed disk having a first surface 6001, an opposing second surface 6002, and a hole 6003 in the center of the disk that passes through the disk from the first surface 6001 to the opposing second surface 6002. Motor components such as the spray-formed part 6000 can be formed to a near-net shape.

[0119] Referring to FIG. 30 , mold assembly or mold 2202 is similar to mold 1902 for disk-shaped part 6000 described above, except that an additional component in the form of a plug or center mask 2203 is secured to build plate 2205. The mold build plate 2205, mold walls 2206, and mold center plug 2203 are separate components and may be made of different materials. A typical material for the build plate is low carbon steel, while the mold components (e.g., mold walls 2206) are aluminum. Mold walls 2206 are secured to build plate 2205 by fixtures 2208. To ensure proper tolerances, alignment fixtures or index pins can be used when assembling mold walls 2206 to build plate 2205. As previously described, the mold assembly is secured prior to grit blasting the surface. Additionally, all previous details regarding the flatness and edge sharpness of the center mask 2203 are adhered to.

[0120] Referring to Figure 31, in one example method of forming part 6000, a trajectory change is made to the spray gun path. The addition of mold center mask 2203 creates an additional angle transition at the wall of center mask 2203. The minimum distance between the mold outer wall and the mold center plug wall is defined by the spray beam spot size and the mold height. This distance is greater than the spot size plus the tangent of the spray angle times the height. The rest of the spray operation is performed in the same way as for disk-shaped parts.

[0121] Still referring to FIG. 31 , the desired values ​​of the particle beam incidence angle at several particle beam incidence points are shown to adequately fill the interior corners of the mold 2202 with the center mask 2203. This is an extension of the splay angle described with respect to the previous embodiment. The vertical walls of the plug (center mask 2203) are subjected to the same or similar procedure as the interior surface of the mold wall 2206. The splay starts at a negative angle at the mold wall 2206, transitions to a 0 degree angle when depositing directly onto the build plate 2205, and then transitions to a positive angle when spraying along the wall of the center mask 2203.

[0122] The mold removal process is similar to that for disks without the center mask 2203, with the following process modifications: After the steel build plate 2205 is removed, the center mask 2203 is then removed. The removal process also takes advantage of the difference in thermal expansion coefficients. The material of the center mask 2203 is aluminum. To remove the center mask 2203, the mold and deposition assembly are heated to 600°C. The heated assembly is removed, and the center mask 2203 is selectively cooled. Cooling can be achieved using ice, dry ice, liquid nitrogen, or other target-selective cooling devices. Multiple temperature cycles may be used because the center mask 2203 conducts heat from the spray material. Once the entire center mask 2203 is free from the deposition spray, removal requires little force.

[0123] A process flow diagram is shown in Figure 32, illustrating the mold filling and removal process for a cylindrical near-net-shape part, such as part 6000. This diagram is similar to Figure 28, but depicts a disk-shaped mold incorporating a central void for the near-net-shape part. An additional step for removing the center mask 2203, which creates the material void, is also outlined. The filling operation is performed similarly to Figure 28, following the procedure shown in Figure 31. A combination of heating and cooling is used to remove the center mask 2203. The entire sample is heated to expand the part, and then selective cooling is applied to the center mask 2203 to reduce its dimensions. As the center mask 2203 shrinks, a force can be applied to push the center mask 2203 out of the center of the mold. Other operations are performed similarly to the procedure shown in Figure 28. Axisymmetric near-net-edge stepped disk with stepped central hole

[0124] Referring to Figure 33, a near net shape part 2300 with two different diameters is illustrated. The shape is similar to part 6000 with a central void. In particular, a stepped edge disk with a stepped center hole 2302 is shown.

[0125] Referring to Figure 34, the deposition and mold removal process for a stepped part 2300 is shown. This process consists of two phases. The near-net part 2300 is more complex than the parts previously described. Part 2300 has multiple inner and outer diameters depending on the part height. For complex part geometries, a multi-step process using a set of molds is employed. This is a desirable feature for parts with surfaces that change from parallel to perpendicular to the particle beam direction of incidence. The multi-step process for part 2300 ensures that deposition always begins with the first deposition plate. When spray-forming parts using molds, a continuous solid is desirable. Voids and discontinuities in the deposit can cause degradation of material performance.

[0126] In manufacturing part 2300, the initial deposition process is similar to the previously described disk with a hole in the center. A mold assembly or mold 2306 includes a build plate 2308, mold walls 2310, and a center plug 2309. However, in the example of manufacturing part 2300, a mask 2304, having the same dimensions as the mold walls 2310 and center plug 2309, is placed on top of the mold walls 2310 and center plug 2309. FIG. 34 shows the mold 2306 and mask 2304 in the first row of the process flow diagram. Previously, the mold height did not matter as long as it was greater than the height of the final part. However, with a stepped mold, the height of the first layer mold must be the same as the target height of the part features. The material deposition process fills the mold cavity until the material reaches the top of the mold, but remains below the mask 2304.

[0127] Once the material has filled the cavities, the mask 2304 part is removed from the mold 2306 and a second mask 2320 with a stepped, larger diameter is installed. The material fills the smallest diameter first and then the larger diameters to ensure continuity. After installing the second mask 2320, the same filling procedure can be applied by aligning the spray path trajectory to the larger diameter.

[0128] The fabrication of this part involves stopping mid-deposition to replace a mold part. After the mold part is replaced, the mold material is grit blasted. Furthermore, when the material deposition process is restarted, the mold 2306 is reheated and deposition resumed using the same procedure as the initial deposition, except that no adhesive pass is used for the restarted spray forming.

[0129] The mold removal procedure is nearly identical to that for a centrally perforated disk. The main difference is that the mold material is directional and can only be removed in one direction. The stepped surface prevents mold removal in both directions, as was possible with previous molds. Additionally, it may be desirable to cool the deposit to facilitate removal of the outer mold wall. [Rectangular near net shape]

[0130] The next section describes near-net forming a rectangular part 2700 using spray deposition techniques. The target shape is shown in Figure 35A. Creating sharp vertical angles with thermal spray can be difficult. Spraying directly onto a build plate without mold walls results in slanted or tapered edges of the spray volume. An example of a tapered edge 2702 is shown in Figure 35B.

[0131] To overcome the edge taper, a mold assembly or mold 2802 can be used, similar to the circular shape previously described. When dealing with parts with straight edges, there are two different approaches. The first is to use a separable multi-piece mold, and the second is to use a single-piece mold for each height, as previously described. In this section, we will discuss a separable multi-piece mold assembly.

[0132] Referring to Figure 36, a rectangular mold assembly or mold 2802 is shown having multiple removable mold walls. The multi-piece mold 2802 has a single-piece build plate 2804. Low carbon steel is selected as the material for the build plate 2804. The mold walls 2806 are constructed of individual pieces for each side. Because the walls 2806 are not a continuous, monolithic structure, several different materials can be selected for the walls 2806. Typical choices are low carbon steel and aluminum.

[0133] Each wall 2806 is secured to the build plate 2804 using fixtures 2809 and tightened to the appropriate torque. Part movement during the deposition process can result in the final shape being the wrong size. Also, gaps between parts in the mold can result in material voids. Faces and edges must meet the same flatness and roundness controls as described for near-net-shape discs.

[0134] After the mold 2802 components are properly secured, the assembly is grit blasted and mounted in a fixture. To properly deposit material in the corners, the particle beam is angled. This angle is the same as in the disk configuration. This angle can be achieved by moving the spray gun 1901 or by moving the sample. Because the rectangular sample mold 2802 does not rotate, the tilting includes an additional dimension. The filling operation, temperature control, and sample cooling are the same or substantially the same as in the disk setup. Depending on the size and shape of the rectangular mold 2802, the compressed air cooling configuration used in the disk setup may be used for temperature control, with appropriate adjustments.

[0135] Continuing with reference to Figure 37, after material deposition, the deposit is allowed to cool to room temperature and then the fixture 2809 can be removed. Because the deposit is not strongly adhered to the mold walls 2806, the walls 2806 can be easily removed from the build plate 2804. Removal of the fixture 2809 releases the compressive stress and the part easily slides off the deposit walls 2806.

[0136] The near-net-shape part remains adhered to the build plate 2804. For large rectangular parts, removing the build plate 2804 can be difficult. A combination of thermal cycling and mechanical force can be used to separate the two parts. The thermal expansion coefficients of the spray-deposited material and low-carbon steel are similar; therefore, thermal cycling does not necessarily result in immediate delamination.

[0137] It may be useful to cut the near-net-shape part 2700 from the build plate 2804. This can be done using electrical discharge machining (EDM), a diamond saw, or an abrasive cut-off wheel, as these techniques are most effective. Core-shell particles may contain ceramic materials that quickly wear out common cutting tools, such as high-speed steel or carbide. Additionally, the nature of spray-formed powders, such as those formed by thermal spraying, makes them difficult to process with high-speed cutting tools, which fracture rather than cut the material. [Extending the working example]

[0138] The teachings described in this example can be extended to other powders used in thermal spray processes and are not limited to core-shell materials. Furthermore, other deposition techniques can be used to deposit the powder, such as high-velocity oxygen-fuel (HVOF), cold spray, or plasma spray, which can be substituted for the high-velocity air-fuel (HVAF) process described above. The above method can be used to manufacture stator winding cores for hybrid field motors, as well as winding cores for transformers and wireless transmission devices that take advantage of three-dimensional magnetic flow. Furthermore, the methods and apparatus disclosed herein can be utilized to manufacture any part suitable for any suitable application.

[0139]

[0008] In some embodiments, a method of manufacturing a stator comprises: Providing a yoke, including a yoke manufactured by spray forming; Providing a tea sling, including a tea sling manufactured by spray forming; Dividing a portion of the teeth ring to form a plurality of teeth; arranging the plurality of teeth in a circular pattern with spaces between each other; fitting a coil onto each of the plurality of teeth, the coil having two leads extending from the same side of the coil; disposing the yoke on the plurality of teeth; placing a housing on said yoke; connecting the coils together at the two leads; Includes:

[0140] Each of the teeth may be wrapped with electrical insulating tape. The method may further include coating each tooth wrapped with electrical insulating tape with epoxy. Arranging the teeth in a circular pattern may include placing each of the teeth on a locating fixture plate. Features on the locating fixture plate may be located between adjacent teeth to align the teeth. Placing a housing on the yoke may include aligning the yoke with the housing relative to locating features on the yoke. Connecting the coils to each other may include connecting the coils in a Y-connection or a delta-connection, and in series or parallel. Connecting the coils to each other may include routing interconnection wiring of the coils along the periphery of the yoke in an annular space defined by the outer surface of the yoke, the surface of the coil, and the housing. The method may further include disposing a temperature sensing device between adjacent coils. The temperature sensing device may be a thermistor valve. The spray-formed yoke and the spray-formed teeth ring may be spray-formed to a near-net shape. The method may further include using a magnet to generate an attractive force on the yoke to bring the yoke into contact with the teeth.

[0141] In another exemplary embodiment, a method of manufacturing a stator comprises: Providing a yoke, including a yoke manufactured by spray forming; Providing a spray-formed tea sling; Dividing a portion of the teeth ring to form a plurality of teeth; arranging the plurality of teeth in a circular pattern with spaces between each other; fitting a coil onto each of the plurality of teeth; disposing the yoke on the plurality of teeth; placing the yoke in an encapsulation mold; connecting the coils to each other; injecting resin into the encapsulation mold; Includes:

[0142] The method may further include removing the encapsulating mold. Injecting the resin into the encapsulating mold may include injecting the resin into an inlet at the bottom of the encapsulating mold, allowing the resin to flow between the coil and exit through an outlet at the top of the encapsulating mold. The resin may be heated to a temperature above a set temperature to reduce the viscosity of the resin so that the resin can flow with a viscosity that fills the spaces between the teeth, the coil, and the yoke. The spray-formed yoke and the spray-formed teeth ring may be manufactured to a near-net shape. The method may further include using a magnet to generate an attractive force on the yoke to bring the yoke into contact with the teeth.

[0143] According to another exemplary embodiment, a method of assembling a stator / rotor assembly for a motor includes the steps of: providing a housing having a bearing sleeve, the bearing sleeve extending radially inward within the housing; Preparing a stator; The stator includes: A stator yoke manufactured by spray forming; a plurality of teeth spaced apart from one another on the stator yoke; a coil fitted to each of the plurality of teeth, the coil being connected to a coil fitted to an adjacent tooth; and the method further comprises: Mounting the stator within the housing and over the bearing sleeve; mounting a bearing adjacent to the bearing sleeve; Mounting a rotor having a rotor yoke and a plurality of magnets on a bearing sleeve; wherein mounting the rotor to the bearing sleeve comprises inserting the rotor into the housing in a stepwise and controlled insertion manner such that an air gap is formed between the stator and the rotor, the air gap being planar and perpendicular to an axis of rotation of the rotor relative to the stator.

[0144] The coils may be connected to each other in a Y-connection or a delta-connection, and in parallel or in series. Mounting the bearing may include assembling an axial thrust bearing to the bearing sleeve. Mounting the bearing may include assembling a radial bearing to the bearing sleeve. Assembling the radial bearing may include eliminating axial gaps between the rotor yoke and the plurality of teeth using magnetic attraction.

[0145] According to another exemplary embodiment, a stator for a three-dimensional flux electric motor comprises: stator yoke and; a plurality of teeth arranged on the stator yoke in a spaced-apart relationship; a coil disposed on each of the plurality of teeth; Each coil is connected to the coil of an adjacent tooth. Each of the plurality of teeth has a main portion and a top portion, the main portion has three side surfaces, the three side surfaces are connected by side edges, the three side surfaces each have a base edge and a top edge adjacent to the side edges, and the top portion is located above the top edge. In each of the plurality of teeth, the top portion has a protruding portion that protrudes outward from the top edge of the main portion. Each of the plurality of teeth allows magnetic flux to flow in at least the axial, radial, and circumferential directions.

[0146] The protruding portion may allow at least a portion of the magnetic flux to flow radially and circumferentially around the teeth. The three side surfaces of the main portion may have chamfered or rounded outer corners at connecting ends defining the three side surfaces. The bases of the three side surfaces may each have a fillet at an inner corner formed by each side surface of the main portion and the stator yoke. The teeth may be formed from an isotropic soft magnetic composite material. The stator yoke may be spray formed to a near-net shape. The teeth may be formed from a teeth ring spray formed to a near-net shape, and the teeth ring may be divided into multiple teeth. The stator yoke may be composed of a planar disk having at least one feature on its surface, the at least one feature configured to position the stator within a housing. The housing may be composed of a single piece of aluminum to provide a heat conduction path from the coil. The stator may be mounted in a housing having a bearing sleeve extending radially inward within the housing. An axial thrust bearing and a radial thrust bearing may be disposed on the bearing sleeve. The teeth and coils of the stator may be encapsulated with epoxy resin. Clearances for accommodating epoxy resin may be formed between the teeth and the coils, between the coils and the housing, and between the stator yoke and the housing to facilitate bonding.

[0147] According to another exemplary embodiment, a three-dimensional flux electric motor comprises: a housing having a bearing sleeve extending radially inward therein; at least one stator mounted within said housing and on said bearing sleeve; and wherein the at least one stator comprises: A stator yoke manufactured by spray forming; a plurality of spaced apart teeth disposed on the stator yoke; a coil disposed on each of the plurality of teeth; Equipped with Each of the coils is connected to the coil of an adjacent tooth; each of the plurality of teeth has a main portion and a top portion, the main portion has three side surfaces, the three side surfaces have a base and a top side, and the top side is located above the top side; the top portion has a protruding portion that protrudes outward from the top edge of the main portion; Each of the plurality of teeth allows magnetic flux to flow in an axial direction, a radial direction, and a circumferential direction; The three-dimensional flux electric motor further comprises at least one rotor mounted on the bearing sleeve, the at least one rotor comprising: a rotor yoke; a plurality of magnets on the rotor yoke; Equipped with. The at least one stator and the at least one rotor are separated by an air gap.

[0148] The stator may be formed from an isotropic soft magnetic composite material, and at least a portion of the stator may be spray formed to a near-net shape.

[0149] The features described herein may be provided in an apparatus. The features described herein may be provided in an assembly method for assembling an apparatus. The features described herein may be provided in a method of using an apparatus having the above features. The features described herein may be provided in control software embodied in memory and usable with a processor and capable of controlling the operation of the apparatus as described above.

[0150] It should also be understood that the above description is merely exemplary. Numerous variations and modifications will occur to those skilled in the art. Furthermore, features from the various embodiments described above may be selectively combined to form new embodiments.

Claims

1. 1. A method of manufacturing a stator, comprising: Providing a yoke, including a yoke fabricated by spray forming; Providing a teeth sling, including a teeth sling manufactured by spray forming; Dividing a portion of the teeth ring to form a plurality of teeth; arranging the plurality of teeth in a circular pattern with spaces between each other; fitting a coil onto each of the plurality of teeth, the coil having two leads exiting from the same side of the coil; disposing the yoke on the plurality of teeth; placing a housing on the yoke; connecting the coils together at the two leads; A method comprising:

2. The method of claim 1 , wherein each of the plurality of teeth is wrapped with electrical insulating tape.

3. 3. The method of claim 2, further comprising coating each of the electrical insulating tape wrapped teeth with an epoxy.

4. The method of claim 1 , wherein arranging the plurality of teeth in a circular pattern includes placing each of the plurality of teeth on a fixture plate.

5. The method of claim 4 , wherein features on the fixture plate are located between adjacent teeth to align the teeth.

6. The method of claim 1 , wherein placing a housing on the yoke includes aligning the yoke with the housing relative to a locating feature of the yoke.

7. The method of claim 1 , wherein connecting the coils together comprises connecting the coils in a wye or delta configuration, and in series or parallel.

8. 8. The method of claim 7, wherein connecting the coils to each other includes routing interconnecting wiring of the coils along a periphery of the yoke in an annular space defined by an outer surface of the yoke, a surface of the coils, and the housing.

9. The method of claim 1 , including disposing a temperature sensing device between adjacent coils.

10. The method of claim 9 , wherein the temperature sensing device is a thermistor valve.

11. 10. The method of claim 1, wherein the spray formed yoke and the spray formed teeth ring are manufactured to near net shape.

12. The method of claim 1 , including using a magnet to generate an attractive force on the yoke to urge the yoke into contact with the teeth.

13. 1. A method of manufacturing a stator, comprising: Providing a yoke, including a yoke fabricated by spray forming; Providing a spray-formed teeth sling; Dividing a portion of the teeth ring to form a plurality of teeth; arranging the plurality of teeth in a circular pattern with spaces between each other; fitting a coil onto each of the plurality of teeth; disposing the yoke on the plurality of teeth; placing the yoke in an encapsulation mold; connecting the coils to each other; injecting resin into the encapsulation mold; A method comprising:

14. The method of claim 13 further comprising removing the encapsulating mold.

15. 14. The method of claim 13, wherein injecting the resin into the encapsulating mold comprises injecting the resin into an inlet at the bottom of the encapsulating mold, allowing the resin to flow between the coils and exit through an outlet at the top of the encapsulating mold.

16. 14. The method of claim 13, wherein the resin is heated to a temperature above a set temperature to reduce the viscosity of the resin to allow the resin to flow with a viscosity such that the spaces between the teeth, the coil, and the yoke are filled.

17. 14. The method of claim 13, wherein the spray formed yoke and the spray formed teeth ring are manufactured to near net shape.

18. The method of claim 13 , including using a magnet to generate an attractive force on the yoke to urge the yoke into contact with the teeth.

19. 1. A method of assembling a stator / rotor assembly for a motor, comprising: providing a housing having a bearing sleeve, the bearing sleeve extending radially inward within the housing; providing a stator; The stator includes: a stator yoke manufactured by spray forming; a plurality of teeth spaced apart from one another on the stator yoke; a coil fitted to each of the plurality of teeth, the coil being connected to a coil fitted to an adjacent tooth; and the method further comprises: Mounting the stator within the housing and over the bearing sleeve; Mounting a bearing adjacent to the bearing sleeve; Mounting a rotor having a rotor yoke and a plurality of magnets on a bearing sleeve; wherein mounting the rotor to the bearing sleeve comprises inserting the rotor into the housing in a stepwise and controlled insertion manner such that an air gap is formed between the stator and the rotor, the air gap being planar and perpendicular to an axis of rotation of the rotor relative to the stator.

20. 20. The method of claim 19, wherein the coils are connected to each other in a wye or delta configuration, and in parallel or series.

21. 20. The method of claim 19, wherein mounting the bearing comprises assembling an axial thrust bearing into the bearing sleeve.

22. 20. The method of claim 19, wherein mounting the bearing comprises assembling a radial bearing into the bearing sleeve.

23. 1. A stator for a three-dimensional flux electric motor, comprising: a stator yoke; a plurality of teeth arranged on the stator yoke in a spaced-apart relationship; a coil disposed on each of the plurality of teeth; Equipped with Each coil is connected to the coil of an adjacent tooth; Each of the plurality of teeth has a main portion and a top portion, the main portion has three side surfaces, the three side surfaces are connected by side edges, the three side surfaces each have a base edge and a top edge adjacent to the side edges, and the top portion is located above the top edge; The top portion of each of the plurality of teeth has a protruding portion that protrudes outward from the top edge of the main portion; Each of the plurality of teeth allows magnetic flux to flow in at least an axial direction, a radial direction, and a circumferential direction; Stator.

24. 24. The stator of claim 23, wherein the overhangs allow at least a portion of the magnetic flux to flow radially and circumferentially about the teeth.

25. 24. A stator according to claim 23, wherein the three sides of the main portion have chamfered or rounded outer corners at connecting ends that define the three sides.

26. 24. The stator of claim 23, wherein the base of each of the three sides has a fillet at an inner corner formed by the respective side of the main portion and the stator yoke.

27. 24. The stator of claim 23, wherein each of the plurality of teeth is formed from an isotropic soft magnetic composite material.

28. 24. The stator of claim 23, wherein the stator yoke is spray formed to a near net shape.

29. 24. The stator of claim 23, wherein the plurality of teeth are formed from a teeth ring that is spray formed to a near net shape, and the teeth ring is divided into the plurality of teeth.

30. 24. The stator of claim 23, wherein the stator yoke comprises a planar disk having at least one feature on a surface thereof, the at least one feature configured to position the stator within a housing.

31. 31. The stator of claim 30, wherein the housing is constructed from a unitary piece of aluminum to provide a thermal conduction path leading from the coil.

32. 24. The stator of claim 23, wherein the stator is mounted within a housing having a bearing sleeve extending radially inwardly within the housing.

33. 33. The stator of claim 32, wherein the bearing sleeve includes an axial thrust bearing and a radial bearing.

34. 24. The stator of claim 23, wherein the stator teeth and coils are encapsulated with epoxy resin.

35. 35. The stator of claim 34, wherein clearances are formed between the teeth and the coil, between the coil and the housing, and between the stator yoke and the housing to accommodate epoxy resin to facilitate bonding.

36. 1. A three-dimensional flux electric motor, comprising: a housing having a bearing sleeve extending radially inward therein; at least one stator mounted within said housing on said bearing sleeve; wherein the at least one stator comprises: a stator yoke manufactured by spray forming; a plurality of spaced apart teeth disposed on the stator yoke; a coil disposed on each of the plurality of teeth; Equipped with each of the coils is connected to a coil of an adjacent tooth; each of the plurality of teeth has a main portion and a top portion, the main portion having three side surfaces, the three side surfaces having a base and a top side, and the top surface being located above the top surface; the top portion has a protruding portion that protrudes outward from the top edge of the main portion, Each of the plurality of teeth allows magnetic flux to flow in an axial direction, a radial direction, and a circumferential direction; The three-dimensional flux electric motor further comprises at least one rotor mounted on the bearing sleeve, the at least one rotor comprising: a rotor yoke; a plurality of magnets on said rotor yoke; Equipped with the at least one stator and the at least one rotor are separated by an air gap; Three-dimensional magnetic flux electric motor.

37. 37. The three-dimensional flux electric motor of claim 36, wherein the overhanging portion of each of the plurality of teeth allows magnetic flux to flow in radial and circumferential directions.

38. 37. The three-dimensional flux electric motor of claim 36, wherein each of said plurality of teeth is formed from an isotropic soft magnetic composite material.

39. 37. The three-dimensional flux electric motor of claim 36 wherein at least a portion of said stator is spray formed to a near net shape.

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