Sealed axial flux motor with integrated cooling

Abstract

The present disclosure relates to an axial flux motor comprising a single rotor and two stators that reduces the size and weight of the motor using a single rotor. An inner housing and an outer housing mechanically support the two stators and engage together to define an inner cavity. A ring seal is provided between the two housings to ensure that the interior is sealed. In addition, the two stators may actuate multiple degrees of freedom (DOF), including rotation of the wheel and actuation of the suspension.

Description

[0001] This application is a divisional application of a patent application with application date of June 17, 2019, application number 201980049944.9, and title “Sealed Axial Flux Motor with Integrated Cooling”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of priority under 35 U.S.C. 119(e) to U.S. Application No. 62 / 685,445, filed on June 15, 2018, entitled “Axial Flux Motor with Cooling System,” which is incorporated herein by reference in its entirety. Technical Field Background Art

[0004] Electric vehicles and hybrid vehicles often use radial flux motors for propulsion. A radial flux motor typically comprises (1) a rotor having a plurality of magnets positioned along the periphery of the rotor such that the magnetic flux lines produced by the magnets are radially oriented relative to the axis of rotation of the rotor, and (2) a stator disposed circumferentially around the rotor having a plurality of coil windings. When current is supplied to the coil windings, the interaction between the magnetic fields of the coil windings and the permanent magnetic fields of the magnets causes the rotor to rotate relative to the stator. The design and manufacture of radial flux motors is well established, which is one of the main reasons for their use in modern electric and hybrid vehicles. However, radial flux motors are limited in efficiency, size, and torque output, especially when compared to other motor topologies.

[0005] For example, axial flux motors can provide many advantages over conventional radial flux motors, including higher efficiency, smaller size, lower weight, and higher torque output. Compared to radial flux motors, axial flux motors include (1) a rotor having a plurality of magnets disposed on a face of the rotor such that the magnetic flux lines generated by the magnets are parallel to the axis of rotation of the rotor, and (2) a stator offset along the axis of rotation of the rotor having a plurality of coil windings. In other words, the rotor and stator in an axial flux motor form a "flat" assembly in which multiple rotors and / or stators can be stacked onto each other along a common axis of rotation. The integration of axial flux motors into electric and hybrid vehicles has historically been limited due to difficulties in manufacturing. However, recent advances in the design and manufacture of axial flux motors have rekindled new interest in the use of axial flux motors in electric and hybrid vehicles. Summary of the invention

[0006] An axial flux motor (also referred to herein as a "motor") can propel the wheels of a vehicle (e.g., an electric vehicle, a hybrid vehicle). The axial flux motor includes a single rotor and two stators to reduce the overall size and weight of the motor. The motor can be modular for ease of assembly and maintenance, and have a main shaft that supports a separate brake assembly. The motor can include an inner housing and an outer housing, each housing supporting a coil assembly that is configured to apply torque to the rotor. The inner housing and the outer housing can together define an inner cavity that accommodates the stator and the rotor, and can protect the stator and the rotor from the external environment. The inner housing and the outer housing can be joined by a ring seal for sealing the inner cavity, thereby preventing contaminants such as mud or water from accidentally penetrating the inner cavity. The stator can cause the rotor to rotate, translate a strut in the suspension, or both.

[0007] In one example, an axial flux motor includes a main shaft; a first housing, the first housing being coaxial with the main shaft and rotatable about the main shaft; a second housing, the second housing being coaxial with the main shaft and rotatable about the main shaft, wherein the first housing and the second housing form a cavity; a seal, the seal being placed between the first housing and the second housing to prevent debris and / or liquid from entering the cavity; a magnetic rotor, the magnetic rotor being in the cavity and rigidly connected to the main shaft; a first stator assembly, the first stator assembly being placed in the cavity and coaxial with the main shaft, for applying a first torque to the magnetic rotor; and a second stator assembly, the second stator assembly being placed in the cavity and coaxial with the main shaft, for applying a second torque to the magnetic rotor.

[0008] The first stator assembly may be rigidly connected to the first housing, and the second stator assembly may be rigidly connected to the second housing. The seal may be between the opposing surfaces of the first housing and the second housing. The seal may be flexible and waterproof. The seal may also allow up to 1 mm of movement between the first housing and the second housing. The axial flux motor may also include a hub at the outer end of the spindle for receiving a wheel. The axial flux motor may also include a brake assembly outside the cavity, wherein the brake assembly includes a brake disc rigidly fixed to the spindle and a caliper pressing a brake pad against the brake disc. Alternatively, the brake assembly may include a drum brake, wherein a brake shoe presses against a portion of a brake drum coupled to the wheel. The brake disc and the brake drum may constitute a brake rotor and a brake caliper, and the brake shoe may constitute a brake actuator. The axial flux motor may also include an electrical conduit extending along at least a portion of the exterior of the first housing for protecting wires connected to the first stator assembly. The electrical wires may be routed to avoid undesirable twisting when the first housing rotates about the spindle. The axial flux motor may also include at least one coolant line co-located with the electrical conduit for delivering coolant to the cavity to cool the first coil stator assembly and / or the second coil stator assembly.

[0009] The axial flux motor may include electrical terminals extending from the first housing and connected to the electrical wires; and a torque link attached to the first housing to within about 1.5 mm of the electrical terminals to connect the axial flux motor to a vehicle chassis. The torque link allows the spindle to move relative to the vehicle chassis without over-stressing the electrical wires. The axial flux motor may also include a heat sink extending from the first housing and / or the second housing for dissipating heat generated by the first coil stator assembly and / or the second coil stator assembly. The axial flux motor may include a first set of bearings between the spindle and the first stator assembly for allowing the first stator assembly to rotate about the spindle; and a second set of bearings between the spindle and the second stator assembly for allowing the second stator assembly to rotate about the spindle.

[0010] In another example, an axial flux motor includes a first coil stator assembly; a second coil stator assembly separated from the first coil stator assembly; a magnetic rotor assembly sandwiched between the first coil stator assembly and the second coil stator assembly; a first bearing assembly supporting the first coil stator assembly for rotation around a rotation axis; a second bearing assembly supporting the second coil stator assembly for rotation around the rotation axis; and a seal surrounding the rotation axis and contacting the first housing and the second housing. The first coil stator assembly includes a first housing and a first plurality of coil assemblies rigidly mounted to a back wall of the first housing and an interior of the first housing. The second coil stator assembly includes a second housing and a second plurality of coil assemblies rigidly mounted to a back wall of the second housing and an interior of the second housing.

[0011] The first coil stator assembly may also include an inlet coolant flow passage extending from the front side of the first housing to at least one coolant flow channel on the back wall of the first housing. In addition, the first coil stator assembly may include an outlet coolant flow passage extending from the front side of the first housing to the coolant flow channel on the back wall of the first housing. There may be a first inlet orifice coupled to the inlet coolant flow passage on the front side of the first housing and a first outlet orifice coupled to the outlet coolant flow passage on the front side of the first housing. Similarly, the second coil stator assembly may include a second inlet orifice and a second outlet orifice for at least one coolant flow channel of the second housing.

[0012] This version of the axial flux motor can have a first torque link having one end connected to the first housing at a first attachment point on the front side of the first housing; and a second torque link having one end connected to the second housing at a second attachment point on the rear side of the second housing. The first attachment point and the second attachment point are opposite to each other relative to the rotation axis. The first inlet aperture and the first outlet aperture can be adjacent to the first attachment point, and the second inlet aperture and the second outlet aperture can be adjacent to the second attachment point. For example, the first inlet aperture, the first outlet aperture, and the first attachment point can fall within a sector having a maximum angle of less than about 40° (e.g., less than about 30°). Similarly, the second inlet aperture, the second outlet aperture, and the second attachment point can fall within a sector having a maximum angle of less than about 40° (e.g., less than about 30°).

[0013] All combinations of the foregoing concepts and the additional concepts discussed in more detail below (provided that these concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of the claimed subject matter appearing at the end of this disclosure are considered to be part of the inventive subject matter disclosed herein. Terms explicitly adopted herein that may also appear in any disclosure incorporated by reference should be given the meaning that best fits the specific concepts disclosed herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Those skilled in the art will appreciate that the drawings are primarily for illustrative purposes and are not intended to limit the scope of the inventive subject matter described herein. The drawings are not necessarily drawn to scale; in some cases, various aspects of the inventive subject matter disclosed herein may be shown exaggerated or enlarged in the drawings to aid in understanding different features. In the drawings, like reference numerals generally refer to similar features (e.g., functionally similar and / or structurally similar elements).

[0015] Figure 1 A front perspective view of an outer housing of an exemplary axial flux electric machine is shown.

[0016] Figure 2A Show Figure 1 A side view of an axial flux motor, showing the outside housing and main shaft.

[0017] Figure 2B Show Figure 1 Front view of an axial flux motor.

[0018] Figure 3A Show Figure 1 Exploded perspective view of an axial flux motor.

[0019] Figure 3B Show Figure 1 Exploded front perspective view of an axial flux motor.

[0020] Figure 4 Show Figure 1 An exploded cross-sectional side view of an axial flux electric machine showing an outer housing, a magnetic rotor assembly sandwiched between two coil assemblies, and an inner housing.

[0021] Figure 5 Show Figure 1 Cross-sectional side view of an axial flux motor.

[0022] Figure 6 Show Figure 1 A cross-sectional front perspective view of an axial flux motor.

[0023] Fig. 7A Show Figure 1A front perspective view of the outer coil stator assembly in an axial flux motor.

[0024] Figure 7B Show Figure 1 Rear perspective view of the inboard coil stator assembly of an axial flux motor.

[0025] Fig. 8A Show Figure 1 Rear view of an axial flux motor.

[0026] Figure 8B Show Figure 1 Rear perspective view of an axial flux motor.

[0027] Fig. 9 Show Figure 1 A partial cutaway front view of an axial flux motor.

[0028] Fig.10 Shown is the integration into the vehicle's suspension and wheel assembly Figure 1 Front perspective view of an axial flux motor.

[0029] Fig.11 Show Fig.10 A cross-sectional front perspective view of the wheel assembly.

[0030] Fig. 12A Show Fig.10 A wheel assembly wherein the coil stator assembly is in a corresponding first rotational position.

[0031] Fig. 12B Show Fig. 12A A wheel assembly wherein the coil stator assemblies are rotated relative to each other to respective second rotational positions, thereby causing translational movement of the wheel assembly.

[0032] Fig. 12C Show Fig. 12B A wheel assembly wherein the coil stator assemblies are rotated relative to each other to respective third rotational positions, thereby causing additional translational movement of the wheel assembly.

[0033] Fig.13 Show Figure 1 A partial cross-sectional side view of an axial flux electric machine showing one of the coolant channels connecting the outside coolant flow path to the inside of the machine.

[0034] Fig.14 Show Fig.10 Front perspective view of the wheel assembly with coolant supply ducting, cables and strain relief features.

[0035] Fig.15A A cross-sectional side view of another exemplary axial flux electric machine is shown with an inner housing partially nested within an outer housing.

[0036] Fig. 15B A cross-sectional side view of another exemplary axial flux electric machine is shown, where the inner and outer housings are similar in shape and size and are joined together via a single ring seal.

[0037] Fig. 15C A cross-sectional side view of another exemplary axial flux electric machine is shown in which the inner housing comprises a sidewall housing connecting the inner housing to the outer housing via a single ring seal.

[0038] Fig.15D A cross-sectional side view of another exemplary axial flux electric machine is shown where an inner housing and an outer housing are coupled together by a sidewall housing and a plurality of ring seals.

[0039] Fig.16A A cross-sectional side view of another exemplary axial flux electric machine and wheel assembly is shown, wherein the cooling fins are disposed in an inboard configuration relative to the wheel assembly.

[0040] Fig. 16B A cross-sectional side view of another exemplary axial flux electric machine and wheel assembly is shown, wherein the cooling fins are disposed in an outboard configuration relative to the wheel assembly.

[0041] Fig. 16C A front perspective view of an exemplary cooling hub is shown with circular disk fins disposed along the perimeter of the hub.

[0042] Fig.16D A front perspective view of another exemplary cooling hub is shown with pin fins disposed on the face of the hub.

[0043] Fig.17A A front perspective view of another exemplary cooling hub is shown having blades disposed on the face of the hub to act as a centrifugal blower.

[0044] Fig. 17B A front perspective view of another exemplary cooling hub is shown having spiral blades disposed along the periphery of the hub.

[0045] Fig. 17C A cross-sectional side view of another exemplary axial flux electric machine and wheel assembly is shown having stator vanes and rotor blades to generate air flow through the wheel assembly.

[0046] Fig.18A An exemplary wheel assembly and axial flux motor are shown in an outboard configuration with a MacPherson strut and rocker and electrical connections running along the MacPherson strut to the axial flux motor.

[0047] Fig.18BAn exemplary wheel assembly and axial flux motor are shown in an outboard configuration with a MacPherson strut and a Panhard rod and a similar Fig.18A The electrical connections of the electrical connections.

[0048] Fig. 18C An exemplary wheel assembly and axial flux motor are shown in an outboard configuration with an A-arm suspension and drive shaft and similar Fig.18A The electrical connections of the electrical connections.

[0049] Fig.19A An exemplary axial flux machine with electrical connections is shown in an inside configuration.

[0050] Fig.19B An exemplary axial flux machine with electrical connections is shown in an outboard configuration.

[0051] Fig. 20 A front view of an exemplary wheel assembly and axial flux motor mounted to a swing arm suspension is shown. DETAILED DESCRIPTION

[0052] Conventional axial flux motors are limited in manufacturing and practical application for a number of reasons. For example, conventional axial flux motors typically use multiple rotors and stators that are stacked on top of each other in an alternating arrangement. The inclusion of multiple rotors and stators increases the overall size and weight of the motor. If the motor is mounted outside the wheel, a larger, heavier motor may reduce the vehicle's mileage, reduce vehicle speed, and increase the vehicle's unsprung mass, thereby reducing vehicle performance. The greater the unsprung mass, the greater the dynamic loads imposed on the wheels and tires, which may result in greater vibrations transmitted to the vehicle and, therefore, less ride comfort. In addition, the coil windings in the stator also generate heat during operation, which can be difficult to dissipate because cooling relies on heat conduction through the stator if the stator is between multiple rotors. As a result, the performance of the motor may be limited due to overheating of the motor components.

[0053] To feasibly propel a vehicle, an axial flux motor should be light and small enough to be mounted on a wheel. It should also contain a casing or housing to protect the rotor and stator from debris such as dirt, rocks, or gravel from the road. This casing or housing should be well sealed to protect the rotor and stator from contaminants such as dirt, dust, brake dust. Over time, infiltration of contaminants from the environment could cause the rotor and / or stator to fail. Additionally, the casing or housing should be easily assembled and disassembled for maintenance.

[0054] The axial flux motor of the present invention can be light and compact, and sealed in a housing that is easy to assemble and disassemble. The axial flux motor can have a single rotor between two coil stator assemblies, each of which can apply torque to the rotor. The use of a single rotor reduces the overall size and weight of the axial flux motor, enabling the motor to be mounted on the outside within the wheel hub. The small size of the axial flux motor can allow for a more modular wheel assembly. For example, a separate brake assembly can be mounted to the spindle instead of being integrated into the axial flux motor. The brake assembly can be a disc brake (e.g., a brake caliper and brake disc mounted to the spindle) or a drum brake (e.g., a brake shoe and brake drum mounted to the wheel) mounted separately from the motor to reduce wheel rotation and / or wheel extension. Such a modular assembly can improve the ease of maintenance, in which case the axial flux motor or brake assembly can be easily accessed and replaced without disassembling other components.

[0055] The axial flux motor may include an inner housing and an outer housing that together define an inner cavity containing a rotor and a coil stator assembly. The inner housing and the outer housing may be joined together using at least one ring seal to seal the inner cavity from the external environment. Additionally, the inner housing and the outer housing may use air cooling (e.g., via heat sinks external to the inner housing and / or the outer housing) and / or liquid cooling (e.g., via coolant flowing through channels integrated into the inner housing and / or the outer housing) to dissipate heat from the two coil stator assemblies.

[0056] Each coil stator assembly can generate torque independently of the coil stator assembly, thereby achieving actuation along two degrees of freedom (DOF) based on the differential motion between the two coil stator assemblies. In one example, each coil stator assembly can be configured to rotate around the main shaft via a corresponding set of bearings. When the coil stator assembly applies torque to the rotor in the same direction, the rotor rotates. The two coil stator assemblies can also be connected to the suspension link so that when the two coil stator assemblies apply torque in opposite directions to the rotor, the rotor translates (linearly moves). In this way, the two coil stator assemblies can provide rotational motion of the wheel and / or translational motion of the suspension, which is impossible in an axial flux motor with a single stator. The motor may also include various features (e.g., stress relief features) to reduce the movement of cables (e.g., cables, coolant pipes), which may cause the cables to fail when the wheels move.

[0057] The accompanying drawings and example embodiments described below are not intended to limit the scope of the embodiments of the present invention to a single embodiment. Other embodiments are also possible by interchanging some or all of the described or shown elements. In addition, in the case where some elements of the disclosed example embodiments can be partially or completely implemented using known components, in some cases, only those parts of such known components necessary for understanding the embodiments of the present invention are described, and detailed descriptions of other parts of such known components are omitted to avoid confusing embodiments of the present invention.

[0058] Exemplary Axial Flux Motor

[0059] Figure 1 , 2A 2B show an exemplary axial flux motor 100 including an outer housing 102 and an inner housing 106 (e.g., a bell housing) each mounted to and rotatable about a central spindle 108 (an axis of rotation defined by the central spindle). As shown, the outer housing 102 and the inner housing 106 may face each other, with the inner housing 106 nested within the outer housing 102. The outer housing 102 and the inner housing 106 together form an inner cavity in which other components of the axial flux motor 100 may be housed and protected from external environmental contaminants such as dirt and water. The inner housing 106 and the outer housing 102 may each be formed of a variety of materials, including but not limited to cast aluminum and other suitable materials.

[0060] Figure 3A and 3B 1 and 10 respectively show an exploded rear perspective view and an exploded front perspective view of the electric machine 100. As shown, the electric machine 100 can be broken down into three main components: a coil stator assembly 126 attached to the outer housing 102, a coil stator assembly 128 attached to the inner housing 106, and a magnetic rotor assembly 146 sandwiched between the two coil stator assemblies 102 and 106. There may be an array of coil assemblies 130 (see Fig. 7A ) is rigidly attached to the inner rear wall of the outer housing 102. The array of coil assemblies 130 can be equally spaced around the rotation axis 114. Similarly, there may be another array of coil assemblies 130 (see Figure 7B ) is rigidly attached to the inner back wall of the inner housing 106. These coil assemblies 130 can also be equally spaced around the rotation axis 114. The two arrays of coil assemblies 130 can be identical (i.e., the coil assemblies are identical, the number of coil assemblies is identical, and the radial positions on their corresponding housings are identical). In the outer coil stator assembly 126, the coil assemblies 130 can be arranged around the array of coil assemblies 130 (see Fig. 7A) is positioned at the outer periphery of the outer housing 102 and is fixed in place by a set of clamps 138 screwed into the outer housing 102. In the inner coil stator assembly 128, the coil assembly 130 can be fixed by an array (see Figure 7B ) and is secured in place by another set of clamps 139 that are positioned around the outer periphery of the coil assembly and screwed into the inner housing 102. The coil assembly is anchored to the housing (not visible in the figure) using similar clamps positioned around the inner periphery of the coil assembly.

[0061] Each coil assembly may include a core 134 and a copper winding 132 wound around the core 134. The core 134 may be generally truncated in a pancake shape in cross-section in a plane perpendicular to the axis of rotation 114. The winding 132 may be wound around an axis parallel to the axis of rotation of the motor 100, thereby generating a generally axially oriented magnetic field. The core 134 may be formed of various materials having relatively high magnetic permeability, including but not limited to sintered steel.

[0062] The magnetic rotor assembly 146 may be a disk structure 148 that houses an array of permanent magnets 150. The permanent magnets 150 may be similar to the coil assembly 130 in that the magnets 150 are equally spaced about the axis of rotation 114. The magnetization of the magnets 150 may be oriented parallel to the axis of rotation 114 and may alternate in direction from one magnet to the next about the array of magnets 150 (e.g., the magnetization may be oriented toward the inner housing 106 or the outer housing 102). The disk structure 148 that houses the magnets 150 may be a ribbed structure with recessed portions that house the magnets 150. The magnets 150 and the recessed portions into which they are housed may be rectangular, leaving wedge-shaped areas between the magnets 150. As shown in FIG. Figure 3A and 3B As shown, material may also be removed from these areas to reduce the weight of the magnetic rotor assembly 146. In the exemplary electric machine 100, there are 24 magnets in the array of permanent magnets 150 and 18 coil assemblies 130 in each array of coil assemblies.

[0063] Figure 4 It is shown that each core 134 can have a flange 136 surrounding one side of the core 134 in contact with the housing. The depth of the flange 136 can be approximately equal to the thickness of the core winding. The core 134 and the flange 136 can be made of sintered steel with relatively high magnetic permeability. The flange 136 can contain the magnetic field generated by the coil. The side of each core 134 (with the flange 136) can maintain good thermal contact with the housing, and the housing is rigidly attached to the core for better heat dissipation.

[0064] The outer housing 102 may have three electrical terminals 140 that may be electrically connected through the housing to an array of coil assemblies 130 in the coil stator assembly 126. The terminals 140 may provide three-phase drive signals to the coils 130 to generate relative torque between the magnetic rotor assembly 146 and the coil stator assembly 126. Similarly, the inner housing 106 may also have three electrical terminals 110 that may be electrically connected through the housing to an array of coil assemblies 130 in the coil stator assembly 128. These terminals 110 may provide three-phase drive signals to the coils 130 to generate relative torque between the magnetic rotor assembly 146 and the coil stator assembly 128.

[0065] Figure 4 It is also shown that the magnetic rotor assembly 146 can be rigidly attached to the main shaft 108. The magnetic rotor assembly 146 and the main shaft 108 can be manufactured as a single part, or manufactured as multiple parts and then assembled after manufacturing. Therefore, the drive signal to the coil assembly 130 can cause the magnetic rotor assembly 146 and the main shaft 108 to rotate together. The outer housing 102 can be supported on the main shaft 108 by a set of bearings 168, which enables the outer housing 102 to rotate relative to the main shaft 108 (or the main shaft 108 can rotate relative to the outer housing 102). Similarly, the inner housing 106 can be supported on the main shaft 108 by bearings 170, which enables the inner housing 106 to rotate relative to the main shaft 108 (or the main shaft 108 can rotate relative to the inner housing 106).

[0066] Figure 5 and 6 Additional cross-sectional views of the coil stator assemblies 126 and 128 relative to the main shaft 108 are shown. The coil stator assemblies 126 and 128 can each rotate about the rotation axis 114 independently of each other without an external mechanical or magnetic coupling to each other (e.g., a mechanical linkage connecting the two coil stator assemblies 126 and 128). The independent movement of the coil stator assemblies 126 and 128 is based in part on excluding or ignoring parasitic forces, such as friction from ring seals or pneumatic coupling between the coil stator assemblies 126 and 128. In a practical axial flux motor, parasitic forces may cause some small but non-negligible coupling between the coil stator assemblies 126 and 128.

[0067] Because the coil stator assemblies 126 and 128 are independently movable without any external linkage, they may not align with each other during operation. Figure 5 and 6 The coil stator assemblies 126 and 128 are shown rotated relative to each other. Figure 4 and 6In FIG. 1 , the two coil stator assemblies 126 and 128 are shown aligned with each other so that the cross-sectional views of the corresponding coil assemblies 130 appear similar (eg, two cores 134 of each coil assembly 130 are shown). In contrast, Figure 5 The two stator assemblies 126 and 128 are shown in a misaligned position, with only the windings 132 of the inner coil assembly 130 shown, while the core 134 and windings 132 of the outer coil assembly 130 are shown.

[0068] The inner housing 106 and the magnetic rotor assembly 146 may be enclosed within the outer housing 106 by a ring (or cover) 104 (e.g., a sealing ring plate). The ring 104 may have a flange 103 having a number of bolt holes 124 arranged around the periphery that align with corresponding threaded holes 125 in the outer housing 102. Bolts may be inserted through the holes 124 to secure the ring 104 to the outer housing 102. A ring seal 166 may then be provided between the inner housing 106 and the assembly of the outer housing 102 and the ring 104 to allow the coil stator assemblies 126 and 128 to rotate relative to each other. In other configurations, the ring 104 may be omitted or integrated as part of the inner housing 106 or the outer housing 102, as described below.

[0069] Inboard and outboard axial flux motor housings

[0070] Figure 1 -8 shows that the inner housing 106 and the outer housing 102 can each be a bell housing. The inner housing 106 can include a cylindrical wall 107 extending from one side of the inner housing 106 supporting the core 134. The ring 104 can have a raised cylindrical collar 105, and when the ring 104 is assembled to the outer housing 102, the cylindrical wall 107 of the inner housing 106 fits into the cylindrical collar. The cylindrical collar 105 can also have a lip 109 extending inwardly. The inner diameter of the raised cylindrical collar 105 can be larger than the outer diameter of the area defined by the cylindrical wall 107, so that the cylindrical collar 105 with the lip 109 and the cylindrical wall 107 form a cavity 164 between the two components (see Figure 5 ) to accommodate the double lip ring seal 166 (see Figure 6 ). Ring seal 166 may be mounted within collar 105 such that an outer surface of ring seal 166 abuts an inner surface of collar 105 and one side of ring seal 166 abuts collar lip 109. The inner surface of ring seal 166 may have a flexible double lip that abuts against an outer surface of cylindrical wall 107 of inner housing 106 as inner housing 106 rotates within outer housing 102.

[0071] The ring seal 166 can form a seal between the inner cavity and the surrounding environment even when the inner housing 106 rotates relative to the outer housing 102. The seal can prevent unwanted debris, such as mud or water, from infiltrating the inner cavity of the axial flux motor 100. In addition, the degree to which the inner housing 106 and the outer housing 102 can rotate independently of each other can also depend on the amount of friction between the ring seal 166 and the cylindrical wall 107. In some cases, the ring seal 166 can allow the inner housing 106 and the outer housing 102 to move a total of about 1 mm relative to each other (e.g., for a total range of motion of 1 mm, each stator can move about 0.5 mm relative to the rotor).

[0072] The ring seal 166 can be flexible and / or waterproof or water-tight. In addition, the ring seal 166 should remain flexible throughout the desired operating temperature range and / or desired operating life. The ring seal 166 should also be compatible with the materials used in the manufacture of the motor 100 and the foreign liquids (e.g., water, oil, mud) encountered during operation. The ring seal 166 should also be configured to resist the penetration of liquid (e.g., coolant, water) when the motor 100 is immersed in the liquid. For example, the ring seal 166 can be identified as being able to withstand the penetration of liquid at a desired pressure.

[0073] The inner housing 106 and the outer housing 102 may have other shapes and / or sizes that form a sealed cavity when assembled. The shape and / or size of the inner housing 106 and the outer housing 102 may depend on several factors, including but not limited to the overall size constraints of the electric machine 100, the desired volume of the interior cavity to accommodate the coil stator assemblies 126 and 128 and the magnetic rotor assembly 146, and the ease with which the interior cavity is sealed from the external environment.

[0074] Figures 15A-15D Several other exemplary motors 1500a-1500d are shown with different designs and assemblies of the inner housing 1506 and the outer housing 1502. For example, Fig.15A An electric machine 1500a is shown in which the inner housing 1506a and the outer housing 1502a are again each bell-shaped housings. As previously described, the inner housing 1506a and the outer housing 1502a define an inner cavity 1564 when assembled. The inner housing 1506a supports the inner coil assembly 1528, and the outer housing 1502a supports the outer coil assembly 1526. The coil assemblies 1526 and 1528 can be rotationally rigidly fixed to the magnetic rotor assembly 1546 of the main shaft 1508, as described above. The inner housing 1506a and the outer housing 1502a are also configured to rotate about the main shaft 1508 via corresponding sets of bearings 1570 and 1568. However, unlike Figure 1Unlike the inner housing 106 and the outer housing 102 shown in FIG. 8 , the inner housing 1506a and the outer housing 1502a can be directly coupled to each other via the ring seal 1504a without a separate ring, thereby simplifying the design and assembly of the motor 100. As shown, the inner housing 1506a can be partially nested in the outer housing 1502a.

[0075] Fig. 15B Another motor 1500b is shown in which the inner housing 1506b and the outer housing 1502b are also bell housings. In this case, the inner housing 1506b and the outer housing 1502b can be substantially the same parts that are directly coupled to each other via the ring seal 1504b. By designing the inner housing 1506b and the outer housing 1502b to be similar, the manufacturing cost can be reduced because the same part can be used as the inner housing 1506b or the outer housing 1502b.

[0076] Fig. 15C Another motor 1500c is shown in which the inner housing 1506c and the outer housing 1502c are flat plates (e.g., circular, rectangular, or another shape). As shown, the inner housing 1506c (or the outer housing 1502c) can be coupled to the sidewall housing 1510 (e.g., via bolts or other suitable fasteners). The sidewall housing 1510 can have a variety of shapes depending on the shapes of the inner housing 1506c and the outer housing 1502c. For example, if the inner housing 1506c and the outer housing 1502c are circular plates, the sidewall housing 1510 can be cylindrical, wherein the assembly of the sidewall housing 1510 and the inner housing 1506c can define a bell housing. The inner housing 1506c and the sidewall housing 1510 can be engaged with the outer housing 1502c via the ring seal 1504c to form a closed cavity 1564. This design may be preferred because the inner housing 1506c and the outer housing 1502c have simpler geometries and are therefore easier to manufacture.

[0077] Fig.15D Another electric machine 1500d is shown in which the inner housing 1506d and the outer housing 1502d are also flat plates. However, in this case, the inner housing 1506d and the outer housing 1502d can be joined to the sidewall housing 1510 via ring seals 1504e and 1504d, respectively. In this way, the inner housing 1506d, the outer housing 1502d, and the sidewall housing 1510 can each rotate independently of each other. The sidewall housing 1510 can be mechanically coupled to another part of the vehicle (e.g., chassis, frame, upright suspension) to provide a fixed mechanical reference relative to at least the inner housing 1506d, the outer housing 1502d, and the magnetic rotor assembly 1546.

[0078] Liquid cooling for axial flux motors

[0079] Figure 1 -8 shows a liquid coolant system integrated into each of the housings 102 and 106. Liquid cooling is preferred if air cooling is not feasible due to insufficient air flow and / or too little exposed surface for the air to dissipate the heat. In addition, liquid cooling may also allow heat to be transferred from the motor 100 to another area of ​​the vehicle where air cooling is more practical (e.g., higher airflow and / or larger surface area). The liquid coolant system may also utilize an onboard plumbing subsystem in the vehicle to generate the coolant flow, thereby enabling a higher power density motor 100.

[0080] As shown, the rear wall of the outer housing 102 may include a coolant flow passage 156 extending around the periphery of the rear wall so that the coolant flowing through the coolant flow passage 156 can approach the coil assembly 130 mounted on the inner side of the rear wall of the outer housing 102 to obtain good thermal contact. Similarly, the back wall of the inner housing 106 may also include a coolant flow passage 158 extending around the periphery of the inner housing 106. Likewise, the liquid coolant flowing through the coolant flow passage 158 can approach the coil assembly 130 disposed on the inner side of the back wall of the inner housing 106 to maintain good thermal contact. As shown, the coolant flow passages 156 and 158 may be formed as recessed channels on the back wall of the outer housing 102 and the rear wall of the inner housing 106, respectively. The recessed channels of the outer housing 102 and the inner housing 106 may be covered by plates 160 and 162, respectively, to surround the corresponding coolant flow passages. The shapes of the coolant flow passages 156 and 158 can reduce air pockets and / or poor fluid flow that can cause damage or wear over time. The coolant flow passages 156 and 158 can also include air bleed valves to facilitate the removal of unwanted air bubbles in the liquid coolant system.

[0081] In other configurations, the cover plates 160 and 162 may define at least a portion of the coolant flow passages 156 and 158. The cover plates 160 and 162 may then be coupled to substantially flat surfaces of the outer shell 102 and the inner shell 106, respectively. This configuration may allow the cover plates 160 and 162 to function as a modular liquid cooling system that may be easily separated and / or replaced with other cooling devices (e.g., heat sinks for air cooling). Additionally, the cover plates 160 and 162 and the shells 102 and 106 may be formed of different materials. For example, the cover plates 160 and 162 may be formed of aluminum, and the shells 102 and 106 may be formed of magnesium or other lighter materials. The coolant may be various types of fluids, including but not limited to water and glycol-based coolants.

[0082] With respect to the inner housing 106 , the cover plate 162 may include a coolant inlet passage 112 a and a coolant outlet passage 112 b for coolant to flow into and out of the coolant flow passage 158 , respectively. Figure 2B Coolant passages 112a and 112b are shown to be located at opposite ends of cover plate 162. To facilitate connection to a cooling system (e.g., pump, radiator), Fig.10 Also shown are coolant inlet and outlet channels 112a and 112b that can be coupled to coolant inlet and outlet orifice connectors 113a and 113b, respectively, for attaching flexible tubing (not shown) to a cooling system. Both coolant orifice connectors 113a and 113b can be disposed inside electric machine 100.

[0083] With respect to the outer housing 102 , the coolant flow passage 156 may include a coolant inlet passage 118 a and a coolant outlet passage 118 b for coolant to flow into and out of the coolant flow passage 156 , respectively. Figure 6 and 9 It is shown that coolant passages 118a and 118b may be formed into the outer housing 102 at opposite ends of the coolant flow passage 156. As shown, the coolant passages 118a and 118b may extend along one side of the housing 102 from the rear side of the housing 102 where the coolant flow passage 156 is located to the front of the housing 102 to which the ring 104 is attached. In this way, the coolant passages 118a and 118b may be disposed on the same side as the coolant passages 112a and 112b (i.e., on the inside of the electric machine 100), and therefore more easily connected to the piping used to flow coolant through both the coolant passages 156 and 158. Fig.13 Also shown are coolant outlet passages 118 b extending along the sides of the outer housing 102 . Fig. 7A Coolant passages 118a and 118b are shown to be each coupled to a coolant inlet orifice connector 119a and a coolant outlet orifice connector 119b, respectively, for attaching flexible tubing (not shown) to a cooling system. It should also be noted that the inlet orifice connector 119a and the outlet orifice connector 119b are also located on the inside of the motor 100.

[0084] Air cooling of axial flux motors

[0085] In another example, the motor 100 may be convectively cooled via air flow through the motor 100 when the vehicle is moving and / or the wheels are rotating. Convection cooling may include natural convection (e.g., when the vehicle is at low speeds) and forced convection (e.g., when the vehicle is at high speeds). Various components of the motor 100, such as the inner housing 106 and the outer housing 102, may also have sufficient thermal capacity to temporarily store some of the heat generated by the coil stator assemblies 126 and 128 so that the motor 100 does not overheat when the vehicle is moved from a static position. The motor 100 may also include an onboard temperature monitoring system that prevents the motor 100 from overheating (i.e., exceeding an operating temperature threshold) in the event that convective cooling is insufficient to dissipate the heat and the heat cannot be adequately absorbed by the components of the motor 100.

[0086] Convective heat transfer may be enhanced by integrating one or more fins on the outer surface of the electric machine 100 (e.g., the outer housing 102, the inner housing 106, and / or the ring 104) to increase the surface area available for convective heat transfer. The fins may be formed directly on the outer housing 102, the inner housing 106, and / or the ring 104 using a variety of manufacturing processes including, but not limited to, sheet metal pressing, casting, forming, welding, brazing, or machining.

[0087] Alternatively, a cooling hub having cooling fins may be mounted to the electric machine 100 to dissipate heat generated by the coil-stator assemblies 126 and 128 . Fig.16A A cooling hub 1600a is shown coupled to the inner housing 106. Also, Fig. 16B A cooling hub 1600b is shown coupled to the outer housing 102. In some designs, there may be cooling hubs 1600a and 1600b on both the inner housing 106 and the outer housing 102.

[0088] like Fig.16A As shown in (16B), the cooling hub 1600a (1600b) may include a hub 1610a (1610b) and a heat sink 1620a (1620b). The hub 1610a (1610b) may be coupled to the motor 100 using bolts or other fasteners. In some cases, a thermal paste, epoxy, or adhesive may be provided between the hub 1610a (1610b) and a surface of the motor 100 to which the cooling hub 1600a (1600b) is mounted (e.g., the inner housing 106 or the outer housing 102) to increase thermal conductivity. The cooling hub 1600a (1600b) may be formed of a thermally conductive material, including but not limited to aluminum. In addition, the cooling hub 1600a (1600b) may be formed using various manufacturing processes, including but not limited to sheet metal folding, casting, forming, welding, brazing, or machining.

[0089] Fig. 16CAn exemplary cooling hub 1600c is shown having fins 1620c which are circular disk fins disposed around the perimeter of the hub 1610c. Fig.16D Another exemplary cooling hub 1600d is shown, where the heat sink 1620d is a pin heat sink disposed on the face of the hub 1610d. As shown, the hub 1610d can include a central opening through which the main shaft 108 can pass. The hub 1610d can be supported by its own set of bearings, or can rely on bearings 168 and / or 170 to rotate around the main shaft 108.

[0090] In some cases, the cooling fins may also be shaped and / or sized to manipulate air flow through the electric machine 100 to further enhance cooling. Fig.17A An exemplary cooling hub 1700a is shown in which curved fins 1720a are disposed on the face of hub 1710a. Fins 1720a may be used as a centrifugal blower to generate a higher velocity air flow around motor 100 as the wheel rotates, thereby increasing convective heat transfer. Fig. 17B Another exemplary cooling hub 1700b is shown in which spiral fins 1720b are disposed on the periphery of hub 1710b to create a similar air flow.

[0091] Fig. 17C Different placements of cooling fins 1730 and 1740 relative to the motor 100, wheel assembly, and other components are shown. For example, the cooling fins may be located within the flow path created by side vents (or other aerodynamic elements) on the vehicle. In another example, the hub 192 may contain rotor blades 1730 that draw air through the wheel assembly and through the motor 100. The design and placement of the cooling hub may receive air from the rotor blades 1730. In another example, stator vanes 1740 may be integrated onto the exterior of the outboard housing 102 (or inboard housing 106) for the same purpose.

[0092] Actuating multiple degrees of freedom (DOF) using axial flux motors

[0093] The coil stator assemblies 126 and 128 in the axial flux motor 100 can each generate torque to rotate the magnetic rotor assembly 146. In addition, the reaction torque generated by the coil stator assemblies 126 and 128 can be used to actuate another mechanism in the vehicle (e.g., suspension). For example, Fig. 9Coil stator assemblies 126 and 128 are shown coupled to torque links 172 and 174, respectively, to transfer the torque generated by each coil stator assembly to the body of the vehicle supporting the motor 100. As shown, the torque link 172 can be connected to an attachment point 176 on the ring 104 via a pivot joint so that the torque link 172 can rotate about the point 176. The attachment point 176 can be located along one side of the motor 100. The torque link 174 can be located on the opposite side of the torque link 172. As shown, the torque link 174 can be connected to an attachment point 178 on a torque link attachment bracket 177 via a pin joint. The torque link attachment bracket 177 can be coupled to the inner housing 106. The torque link attachment bracket 177 can be shaped to position the attachment point 178 at a radial distance (i.e., a distance from the axis of rotation 114) that is substantially similar to the radial distance of the attachment point 176. Fig. 9 Attachment points 176 and 178 are shown positioned at angles of approximately 90° and 270°, respectively, along the inside of motor 100, with 0° corresponding to the top of motor 100. The other ends of torque links 172 and 174 may be attached directly to the vehicle, or indirectly to the vehicle via rigid connection brackets 173 and 175, such as Fig.14 shown.

[0094] Fig.10 , Fig.11 and Fig.14 A vertically oriented support structure 188 is shown having a wheel bearing 194 that holds the main shaft 108. A wheel rim 192 may be bolted to the outboard end of the main shaft 108, and a brake disc 186 may be bolted to the inboard end of the main shaft 108. The wheel bearing 194 allows the wheel rim 192, the magnetic rotor assembly 146 that may be rigidly coupled to the main shaft 108, and the brake disc 186 to rotate about the axis of rotation 114 of the main shaft 108. A brake pad assembly 190 may be mounted on the support structure 188 across the brake disc 186.

[0095] The support structure 188 can be connected to a vehicle frame or body (not shown) via an A-frame suspension assembly that includes an upper A-arm 180 attached to the upper end of the support structure 188 and a lower A-arm 182 attached to the lower end of the support structure 188. The upper A-arm 180 and the lower A-arm 182 allow the vehicle body to move up and down relative to the wheels and the motor 100. A spring and damper assembly 184 can be connected between the lower A-arm 182 and a point rigidly connected to the frame or body to support the vehicle in a fixed position relative to the ground. The spring and damper assembly 184 can also allow the vehicle to move up and down in response to (1) bumps encountered along the road surface as the vehicle moves and (2) torque generated by the inner coil stator assembly 126 and the outer coil stator assembly 128 (as described in more detail below).

[0096] Actuating different DOFs via the axial flux motor 100 can be best understood by examining the two operating modes separately. In the first mode, the coil stator assemblies 126 and 128 can only generate rotational motion of the wheels. In this mode, the coil stator assemblies 126 and 128 can each apply torque to the magnetic rotor assembly 146. The torque can be directed in the same rotational direction, thereby causing the magnetic rotor assembly 146 to rotate in the same direction (e.g., as shown in FIG. 1 ). Fig. 9 The stator assemblies 126 and 128 rotate in opposite directions (eg, counterclockwise) relative to the rotor assembly 146. Fig. 9 , torque link 172 moves in an upward direction and torque link 174 moves in a downward direction. If the drive signals for controlling coil stator assemblies 126 and 128 are configured such that the resulting reaction torques from the stator assemblies produce upward and downward forces of substantially equal magnitude, spindle 108 and motor 100 remain in a fixed position relative to the vehicle while magnetic rotor assembly 146 and wheel rim 192 rotate in a clockwise direction.

[0097] In the second mode, the coil stator assemblies 126 and 128 may only generate translational motion of the wheels relative to the vehicle. In this mode, the drive signals to the coil stator assemblies 126 and 128 are selected to generate substantially equal offset torques on the magnetic stator assembly 146. For example, the inner coil stator assembly 128 may apply a torque to rotate the magnetic rotor assembly 146 in a clockwise direction, while the outer coil stator assembly 126 may apply a torque to rotate the magnetic rotor assembly 146 in a counterclockwise direction. Therefore, the applied torques cancel and the magnetic rotor assembly 146 does not rotate. However, the reaction torques generated by the inner coil stator assembly 128 and the outer coil stator assembly 126 may cause the torque links 174 and 172 to rotate in counterclockwise and clockwise directions, respectively, thereby generating a net downward force (relative to the motor 100). Since the locations of the attachment points 176 and 178 are fixed relative to the frame or body of the vehicle, the spindle 108 and attached rim 192 will move upward relative to the vehicle. Figures 12A-12C A series of views are shown depicting the rise of the motor as the coil stator assemblies 126 and 128 rotate relative to a reference line 196 representing the level of the vehicle to which the motor 100 is attached.

[0098] In practice, the motor 100 can produce a combination of both the first mode and the second mode. In other words, the motor 100 can be used to rotate the wheel to propel the vehicle, and can also be used to translate the wheel relative to the vehicle to provide active suspension. As demonstrated in the above description, it should also be understood that the term "stator" (e.g., as in a coil stator assembly) and in the claims is not meant to imply that the element is a fixed, non-rotating component. On the contrary, the above-mentioned coil stator assembly can rotate and / or move in other ways relative to the main shaft 108 and the vehicle.

[0099] Vehicle Suspension

[0100] Fig.10 , 11 14 show an exemplary suspension that can be coupled to the motor 100. Other types of suspensions can also be actuated via the force output from the motor 100. For example, Fig.18A An exemplary suspension 1800a is shown having a MacPherson strut 1802 and a rocker arm 1820. As shown, the suspension 1800a can include a lower A-arm support 182 to couple a support structure 188 (e.g., a vertical suspension) to a vehicle chassis (not shown). The MacPherson strut 1802 can include a strut tube 1812 rigidly coupled to the support structure 188 so that the strut tube 1812 and the support structure 188 move together as a single unit. The strut tube 1812 supports a strut mount 1810 that is attached to the vehicle chassis and slidably adjustable relative to the strut tube 1812 to provide a translational DOF.

[0101] The rocker arm 1820 can couple the motor 100 to the MacPherson strut 1802 for actuation. Specifically, the rocker arm 1820 can rotate about a pivot point 1824 defined by the strut tube 1812, wherein one end of the rocker arm 1820 is coupled to the strut mount 1810 and the other end is coupled to the outboard housing 102 and the inboard housing 106 via respective torque links 1822 and corresponding pin joints. If the outboard housing 102 and the inboard housing 106 rotate in opposite directions relative to each other, the resultant movement of the torque link 1822 rotates the rocker arm 1820, thereby translating the strut mount 1810 relative to the strut tube 1812.

[0102] Fig.18BAnother suspension 1800b is shown that uses a MacPherson strut 1802 in combination with a Panha bar 1830. The Panha bar 1830 can rotate about a pivot point 1834 that is aligned parallel to the axis of rotation 114 and located at one end of the Panha bar 1830. The pivot point 1834 can be attached to the strut tube 1812 and / or the support structure 188 via another support member (not shown). The opposite end of the Panha bar 1830 can be coupled to the strut mount 1810. The center of the Panha bar 1830 can be coupled to the outboard housing 102 and the inboard housing 106 of the motor 100 via respective torque links 1832. Similar to the suspension 1800a, if the outboard housing 102 and the inboard housing 106 rotate in opposite directions relative to each other, the resultant movement of the torque link 1832 causes the Panha bar 1830 to rotate about the pivot point 1834, thereby translating the strut mount 1810 relative to the strut tube 1812.

[0103] Fig. 18C Another suspension 1800c is shown, which includes a support structure 188 that supports the motor 100 connected to the vehicle chassis via the lower A-arm 182 and the upper A-arm 180. In this case, the suspension 1800c includes a drive shaft 1844 that outputs the differential torque between the coil stator assemblies 126 and 128. The drive shaft 1844 can be connected to the vehicle chassis via another mechanism (not shown) to provide actuation of the suspension along the DOF defined by the constraints imposed by the A-arms 180 and 182. The support structure 188 can constrain the rotation range of the coil stator assemblies 126 and 128. As shown, the linkage 1840 can connect the support structure 188 to the outer housing 102 and the inner housing 106 of the motor 100. The linkage 1840 includes a corresponding torque link 1842 that is rotatably connected to the outer housing 102 and the inner housing 106. Additionally, the linkage 1840 may be rotatably coupled to the support structure 188. When the outer housing 102 and the inner housing 106 are relatively moved relative to each other, the torque link 1842 may limit the distance that the outer housing 102 and the inner housing 106 move relative to each other.

[0104] The type of suspension, or more generally the type of mechanism, actuated by the motor 100 may also depend on whether the motor 100 is mounted inboard or outboard relative to the hub 192 and wheel 500 . Fig.19A and 19B The motor 100 is shown mounted on the inside and outside, respectively. Fig.19A In the case of an inboard mounted motor 100, the motor 100 and active suspension mechanism 1852 are mounted on the chassis side of the suspension so that these components are part of the sprung mass of the vehicle. A pair of universal joints 1950a and 1950b can be used to transfer torque output from the motor 100 to the wheels 500 for traction. As shown, Fig.19A The suspension in includes a support structure 188, a lower A-shaped arm 182 and an upper A-shaped arm 180. The active suspension mechanism 1852 can be connected to the support structure 188 using a separate mechanism (not shown). Fig.19B The motor 100 is shown mounted on the outside of the wheel 500. This configuration is similar to the suspensions 1800a-1800c described above. In both configurations, the hub 192 is mounted on the outside end of the spindle 108. Fig.19A , main shaft 108 includes universal joints 1950a and 1950b.

[0105] Fig. 20 A swing arm suspension 2000 for a motorcycle, bicycle or scooter is shown. As shown, the motor 100 can be mounted to a support structure 188, which can be a fork structure that mechanically supports both sides of the wheel 500. The support structure 188 can in turn be mounted to the chassis of the vehicle via an arm 2062 (e.g., a front arm, a trailing arm) that is rotatably coupled to the support structure 188 and the vehicle chassis. The arm 2062 can be used to constrain the movement of the wheel 500 to a curved path (e.g., an arc). The support structure 188 can also be coupled to the vehicle via a MacPherson strut 2002. Specifically, a strut tube 2012 can be rotatably coupled to the support structure 188. The motor 100 can be coupled to a strut mount 2010 via a rod 2060 that is rotatably coupled to both the vehicle and the motor 100. Therefore, the rod 2060 can be actuated by the motor 100 so that the rod 2060 translates the strut mount 2010 along the strut tube 2012. In some cases, the motor 100 may include a counter-rotation mechanism that transfers the reaction torque applied to the inner housing 106 to the outer housing 102 (or vice versa). Therefore, the rod 2060 may only need to be connected to one of the outer housing 102 or the inner housing 106.

[0106] Routing cables to axial flux motors

[0107] The relative movement of the coil stator assemblies 126 and 128 can cause the cables and / or pipes (e.g., cables, coolant pipes) connected to the motor 100 to move. This movement may twist, flex, or bend the cables and / or pipes, ultimately causing the cables and / or pipes to fail. Therefore, it is desirable to reduce the movement of the cables when the motor 100 rotates and translates the wheel. This can be achieved in part by placing all electrical and fluid connections on the same side of the motor 100 near the attachment point between the motor 100 and the suspension. For example, a motor 100 using liquid cooling may have a coolant flow path on each coil stator assembly, and the coolant flow path is arranged so that the pipe is disposed on the inner side of the motor 100 as described above.

[0108] Cables for coil stator assemblies 126 and 128 may similarly be disposed on the inside of motor 100. For example, Fig. 8A , 8B 9 shows that the outer housing 102 includes a recessed area (channel, groove or conduit) 120 located between the coolant channels 118a and 118b. The recessed area 120 surrounds the rear side of the outer housing 102 and extends upward to the electrical terminal 140 on one side of the outer housing 102. The recessed area 120 accommodates three conductors 122 (busbars), which are connected to the electrical terminal 140 and extend forward to the inside of the motor 100 within the recessed area 120, wherein the conductors 122 are connected to the electric drive control system (not shown) of the motor. The conductors 122 may be in a conduit or sheath (not shown) for additional protection. The three conductors 122 may supply three-phase power (e.g., ABC, RYB, UVW) to the motor 100.

[0109] Fig.10 and 11 A three-prong electrical connector 123 is shown at the end of the conductor 122 for electrical connection to the vehicle's drive signal system. As with the cooling system, electrical access to the coil assembly 130 can be made on the same side (e.g., inside) of the motor 100 for both coil stator assemblies 126 and 128 to facilitate connections and cable routing.

[0110] Another way to reduce unwanted movement of the cables is to place the cables near the attachment points 176 and 178 of the torque links 172 and 174, respectively. Since the attachment points 176 and 178 are connected to the vehicle through the torque links, when the coil stator assemblies 126 and 128 rotate to produce lateral translation of the motor 100, the points 176 and 178 will move less than other locations on the motor 100. This ensures that the cables experience less flexing and stress when connected to the motor 100.

[0111] The wires (and coolant conduits) may extend along the torque link to reduce unwanted bending and twisting of the wires (and coolant conduits). Additionally, the distance between the torque link attachment points 176, 178 and the electrical terminals may be selected to reduce unwanted bending and twisting. Technically, the distance should meet the creepage and clearance distances between conductors as specified by applicable safety standards (e.g., ISO, IEC). For low voltages (i.e., 48V), this distance may be 0.1 mm to 1.5 mm. This distance may also be greater than or equal to the bend radius of the wire, depending on the wire diameter, composition, and coating.

[0112] for Fig. 9In the illustrated motor 100, the orifice connectors 113a and 113b of the cooling system may be angled (e.g., 45°) such that the conduit for flowing coolant is coupled closer to the attachment point 178 (e.g., by adjusting the radial position of the conduit to be similar to the radial distance of the attachment point 178). More generally, the electrical connectors, the attachment points for the torque links, and the inlet and outlet ports for the coolant on each side of the motor 100 should preferably be located within a circular sector that subtends an angle of less than about 40°. To reiterate, it is desirable to keep this angle small so that the various connection points for the cables are close to the corresponding attachment points, thereby reducing the vertical movement experienced by the cables during translational movement of the motor 100.

[0113] In yet another approach, coupling the motor 100 to a structural component of the vehicle can also limit the range of motion of the coil stator assemblies 126 and 128. As described above, the coil stator assemblies 126 and 128 can be mounted on the motor 100 so that each stator assembly is free to rotate around the rotation axis 114 independently of each other and independently of the magnetic rotor assembly 146. The torque links 172 and 174, the A-frame suspension, and the support structure 188 can be configured to limit the range of motion of the coil stator assemblies 126 and 128. For example, the coil stator assemblies 126 and 128 can be constrained to move in opposite directions relative to the rotation axis 114. In other words, if the inner coil stator assembly 128 rotates 10° in a clockwise direction around the rotation axis 114, the outer coil stator assembly 126 should rotate 10° in a counterclockwise direction around the rotation axis 114.

[0114] Fig.10 and 14 An exemplary configuration of an axial flux motor 100 is shown coupled to a suspension having conduits for coolant and electrical wiring for controlling coil stator assemblies 126 and 128. As shown, a coolant supply conduit 200 may be connected to the coolant inlet orifice connector 113a, and a coolant return conduit (not shown) may be connected to the coolant outlet orifice connector 113b for the outer coil stator assembly 126. A cable 210 may be connected to the electrical terminals 123 to supply a drive signal to the outer coil assembly 130 in the outer coil stator assembly 126. A similar arrangement may be used to connect cables to the inner coil stator assembly 128. A coolant supply conduit 202 may be connected to the coolant inlet orifice connector 119a, a coolant return conduit (not shown) may be connected to the coolant outlet orifice connector 119b, and a cable 204 may be connected to the three terminals 110 (see Fig. 9 ) to supply a drive signal to the inner coil assembly 130 in the inner coil stator assembly 128.

[0115] As described above, rotational movement of the inner housing 106 and the outer housing 102 may cause the attachment points 176 and 178 to undergo translational movement. This rotational movement may be directed to the terminals 123 ( Fig.10 ) and 110( Fig. 9 ) of cables 210 and 204 (see Fig.14 ) torsional motion is applied to the cables. It is undesirable to experience such stress on the cables, especially since the cables are typically a bundle of twisted pairs that will resist torsional motion. If the cables are twisted too much or too often, they will experience more wear and possibly fail. To reduce unwanted torsional motion, the cables can be routed in a manner that prevents torsional motion when the inner housing 106 and outer housing 102 are rotated.

[0116] For example, each cable 204 and 210 may be mechanically supported by the motor 100 such that the cables are oriented in an approximately 90° bend relative to the electrical terminals 110 and 123 (e.g., the terminals 110 and 123 may be oriented parallel to the axis of rotation 114, and the cables 204 and 210 may be aligned along a radial axis orthogonal to the axis of rotation 114). To support this cable orientation, a strain relief bracket 206 may be mounted to the frame to secure the cables 204, ensuring that the cables 204 follow a path that is approximately 90° relative to the direction in which the cables 204 leave their connection point at or near the terminals 110. Fig.14 In FIG. 1 , the terminal 110 is oriented at an angle of approximately +45° (relative to the inside of the motor 100 ) similar to the coolant tubes 200 and 202 , and therefore, the strain relief bracket 206 secures the cable 204 at an angle of approximately −45° (corresponding to a 90° bend). Similarly, another strain relief bracket 208 may be used to support the cable 210 . Fig.14 , the terminals 123 are oriented at an angle of approximately 90° relative to the inside of the motor 100. Thus, the strain relief bracket 208 secures the cable 210 at an angle of approximately 0° (i.e., substantially parallel to the inside of the motor 100) corresponding to a 90° bend. In this manner, rotational movement of the housings 102 and 106 will cause the cables 204 and 210 to bend at the strain relief brackets 206 and 208, respectively, rather than twist.

[0117] Additionally, the manner in which the cables are routed to other vehicle subsystems may also depend on whether the motor 100 is mounted inboard or outboard relative to the wheel 500. For example, if the motor 100 is mounted outboard relative to the wheel 500 (thereby contributing to the unsprung mass of the vehicle), the effect of the vehicle chassis moving relative to the motor 100 on the cable motion should also be considered. Fig.18ACables 1804 (electrical cables, coolant lines) are shown to be routed from the motor 100 along a path that is initially horizontal to the ground plane of the vehicle, and then bends approximately 90° (e.g., via stress relief features) to translate along the MacPherson strut 1802. This path can reduce unnecessary torsional movement of the cables described above.

[0118] Fig.19B Another exemplary set of cables 1804 is shown also routed along a linkage connected to a strut mount 1810. In contrast, if the motor 100 is mounted inside the vehicle chassis, the routing of the cables can be more flexible because the motor 100 moves with other vehicle subsystems mounted on the chassis. For example, Fig.19A Cable 1904 is shown as being routed from motor 100 along a path defined by a support structure on the chassis.

[0119] in conclusion

[0120] All parameters, dimensions, materials, and configurations described herein are intended to be exemplary, and actual parameters, dimensions, materials, and / or configurations will depend on one or more specific applications for which the present teachings are used. It should be understood that the foregoing embodiments are presented by way of example only, and within the scope of the appended claims and their equivalents, the inventive embodiments may be practiced in a manner different from that specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and / or method described herein.

[0121] In addition, any combination of two or more such features, systems, articles, materials, kits and / or methods (if such features, systems, articles, materials, kits and / or methods are not mutually inconsistent) is included in the inventive scope of the present disclosure. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the corresponding elements of the embodiment without departing from the scope of the present disclosure. The use of numerical ranges does not exclude equivalent values ​​outside the range that achieve the same function in the same way to produce the same result.

[0122] In addition, various inventive concepts may be embodied as one or more methods, at least one example of which has been provided. The actions performed as part of a method may be ordered differently in some cases. Accordingly, in some inventive embodiments, the corresponding actions of a given method may be performed in an order different from the order specifically described, which may include performing some actions simultaneously (even if such actions are shown as sequential actions in the illustrative embodiments).

[0123] All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety.

[0124] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms.

[0125] As used herein in the specification and claims, the indefinite articles "a" and "an" should be understood to mean "at least one" unless explicitly indicated to the contrary.

[0126] As used herein in the specification and claims, the phrase "and / or" should be understood to mean "either one or both" of the elements so combined, i.e., the elements are present in combination in some cases and separately in other cases. Multiple elements listed with "and / or" should be interpreted in the same manner, i.e., "one or more" of the elements are so combined. In addition to the elements specifically indicated by the "and / or" clause, other elements may optionally be present, whether related or unrelated to those specifically indicated. Thus, as a non-limiting example, when used in conjunction with open language (e.g., "including"), reference to "A and / or B" may refer to only A (optionally including elements other than B) in one embodiment; to only B (optionally including elements other than A) in another embodiment; to both A and B (optionally including other elements) in yet another embodiment; and so on.

[0127] As used herein in this specification and claims, "or" should be understood to have the same meaning as "and / or" as defined above. For example, when multiple items are separated in a list, "or" or "and / or" will be interpreted as inclusive, that is, including at least one, but also including more than one element in several elements or element lists and optionally additional unlisted items. Only terms that clearly indicate the opposite, such as "only one of..." or "just one of..." or "consisting of..." when used in the claims will refer to including exactly one element in multiple elements or element lists. In general, the term "or" as used herein, when preceded by exclusive terms such as "any", "one of...", "only one of..." or "just one of...", should only be interpreted as indicating exclusive alternatives (that is, "one or the other but not both"). "Substantially consisting of..." when used in the claims, should have its ordinary meaning as used in the field of patent law.

[0128] As used herein in the specification and claims, when referring to a list of one or more elements, the phrase "at least one" should be understood to refer to at least one element selected from any one or more elements in the list of elements, but does not necessarily include at least one of each element specifically listed in the list of elements, and does not exclude any combination of elements in the list of elements. This definition also allows elements other than the elements specifically identified in the list of elements to be optionally present, whether or not they are related to those specifically identified elements. Thus, as a non-limiting example, in one embodiment, "at least one of A and B" (or, equivalently, "at least one of A or B" or, equivalently, "at least one of A and / or B") may refer to at least one, optionally including more than one A, without B (and optionally including elements other than B); in another embodiment, may refer to at least one, optionally including more than one B, without A (and optionally including elements other than A); in yet another embodiment, may refer to at least one, optionally including more than one A, and at least one, optionally including more than one B (and optionally including other elements); and so on.

[0129] In the claims and in the foregoing specification, all transitional terms such as "comprising," "including," "with," "having," "containing," "involving," "containing," "consisting of," etc., shall be understood to be open, i.e., meaning including but not limited to. As set forth in Section 2111.03 of the U.S. Patent Office Manual of Patent Examining Procedures, only the transitional phrases "consisting of" and "consisting essentially of" shall be closed or semi-closed transitional phrases, respectively.

Claims

1. An axial flux motor, comprising: Spindle; a first housing, the first housing being coaxial with the main axis and rotatable around the main axis; a second shell, the second shell is coaxial with the main axis and can rotate around the main axis, the first shell and the second shell form a cavity, and the second shell can rotate relative to the first shell; a linkage mechanism rotatably coupled to the first housing and the second housing to constrain movement of the first housing relative to the second housing, wherein the linkage mechanism is not directly coupled to a vehicle chassis and allows movement of a rotational axis of the axial flux motor relative to the vehicle chassis; a seal between the first shell and the second shell for preventing debris and / or liquid from entering the cavity; a magnetic rotor in the cavity and rigidly connected to the spindle; a first stator assembly in the cavity and coaxial with the main shaft for applying a first torque to the magnetic rotor; as well as a second stator assembly in the cavity and coaxial with the main shaft for applying a second torque to the magnetic rotor, Wherein, the seal is flexible and waterproof. 2 . The axial flux electric machine of claim 1 , wherein the first stator assembly is rigidly connected to the first housing and the second stator assembly is rigidly connected to the second housing. 3 . The axial flux machine of claim 1 , wherein the seal is between opposing surfaces of the first housing and the second housing. 4 . The axial flux motor of claim 1 , wherein the seal is configured to allow at most 1 millimeter of movement between the first housing and the second housing.

5. The axial flux motor of claim 1 , further comprising: A hub is at the outboard end of the spindle for receiving a wheel.

6. The axial flux motor of claim 1 , further comprising: An electrical conduit extends along at least a portion of an exterior of the first housing for protecting electrical wires connected to the first stator assembly.

7. The axial flux motor of claim 1, wherein the electrical wires are routed to avoid twisting when the first housing rotates about the main axis.

8. The axial flux motor of claim 6, wherein: The connecting rod mechanism comprises: a torque link attached to the first housing; and The axial flux motor further comprises: an electrical terminal extending from the first housing and connected to the electrical wire, Wherein the torque link allows the spindle to move relative to the vehicle chassis without over-stressing the wires.

9. The axial flux motor of claim 1 , further comprising: A heat sink is thermally coupled to the first housing and / or the second housing for dissipating heat generated by the first coil-stator assembly and / or the second coil-stator assembly.

10. The axial flux motor according to claim 9, wherein the heat dissipation device comprises: At least one coolant flow channel is disposed adjacent to at least one of the first coil stator assembly or the second coil stator assembly to carry a flow of coolant that dissipates heat generated by at least one of the first coil stator assembly or the second coil stator assembly.

11. The axial flux electric machine of claim 10, wherein the at least one coolant flow channel comprises: a first coolant flow channel formed in the first housing; as well as A second coolant flow passage is formed in the second housing.

12. The axial flux motor according to claim 11, wherein the heat dissipation device further comprises: a first pair of port connectors fluidly coupled to the first coolant flow passage to carry coolant into and out of the first coolant flow passage; as well as a second pair of port connectors fluidly coupled to the second coolant flow passage to carry the coolant into and out of the second coolant flow passage, Wherein, the first pair of orifice connectors and the second pair of orifice connectors are located on the same side of the axial flux motor.

13. The axial flux motor according to claim 10, wherein the heat dissipation device further comprises: One or more heat sinks for convectively dissipating heat generated by at least one of the first coil-stator assembly or the second coil-stator assembly.

14. An axial flux motor, comprising: Spindle; a first housing, the first housing being coaxial with the main shaft and rotatable about the main shaft via a first set of bearings disposed between the first housing and the main shaft; a second housing, the second housing being coaxial with the main shaft and rotatable about the main shaft via a second set of bearings disposed between the second housing and the main shaft, the first housing and the second housing forming a cavity, the second housing being rotatable relative to the first housing; a linkage mechanism rotatably coupled to the first housing and the second housing to constrain movement of the first housing relative to the second housing, wherein the linkage mechanism is not directly coupled to a vehicle chassis and allows movement of a rotational axis of the axial flux motor relative to the vehicle chassis; a seal disposed between the first shell and the second shell to prevent debris and / or liquid from entering the cavity, the seal being flexible and waterproof; a magnetic rotor in the cavity and rigidly connected to the spindle; a first coil-stator assembly within the cavity and rigidly connected to the first housing for applying a first torque to the magnetic rotor; a second coil-stator assembly within the cavity and rigidly connected to the second housing for applying a second torque to the magnetic rotor; a wheel hub mounted to the outboard end of the spindle; a wheel mounted to the hub for propelling the vehicle; a brake assembly disposed outside the cavity and coupled to the spindle for reducing a rotational speed of the wheel; a suspension mechanically connecting the wheel hub to a chassis of the vehicle, the suspension being coupled to the first coil stator assembly via the first housing and to the second coil stator assembly via the second housing such that when the first torque and the second torque differ in magnitude and / or direction, the first coil stator assembly and the second coil stator assembly actuate the suspension to translate the wheel hub relative to the chassis; a heat sink thermally coupled to the first housing and / or the second housing for dissipating heat generated by the first coil-stator assembly and / or the second coil-stator assembly; as well as A cable is connected to the first housing for supplying power to the first coil stator assembly, the cable being routed along at least a portion of the suspension to avoid twisting when the first housing rotates about the spindle.

15. The axial flux motor according to claim 14, wherein the heat dissipation device comprises: At least one coolant flow channel is disposed adjacent to at least one of the first coil stator assembly or the second coil stator assembly to carry a flow of coolant that dissipates heat generated by at least one of the first coil stator assembly or the second coil stator assembly.

16. The axial flux motor according to claim 14, wherein the heat dissipation device further comprises: One or more heat sinks for convectively dissipating heat generated by at least one of the first coil-stator assembly or the second coil-stator assembly.

17. A method of operating an axial flux electric machine, comprising: applying a first torque to the magnetic rotor using a first coil stator assembly rigidly connected to the first housing; applying a second torque to the magnetic rotor simultaneously with the application of the first torque using a second coil stator assembly rigidly connected to a second housing, the first housing and the second housing forming a cavity; as well as while applying the first torque and the second torque to the magnetic rotor, maintaining a seal on the cavity to prevent debris and / or liquid from entering the cavity, wherein the first torque generates a corresponding first reaction torque that causes the first housing to rotate relative to the second housing, wherein the wires connected to the first housing are routed to avoid twisting in response to rotation of the first housing, wherein the first housing is connected to the second housing via a linkage mechanism, Wherein the linkage is not directly coupled to the chassis of the vehicle and allows the axis of rotation of the axial flux motor to move relative to the vehicle chassis.

18. The method according to claim 17, further comprising: In response to applying the first torque and the second torque to the magnetic rotor, at least one of rotating the magnetic rotor or translating a hub coupled to the magnetic rotor is performed.

19. The method according to claim 17, further comprising: While applying the first torque and the second torque, heat generated by the first coil stator assembly and / or the second coil stator assembly is dissipated using a heat sink thermally coupled to the first housing and / or the second housing.

20. The method according to claim 17, wherein dissipating heat using a heat sink comprises: A coolant is flowed through at least one coolant flow channel disposed proximate to at least one of the first coil stator assembly or the second coil stator assembly.

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