Electric motor with integrated cooling system

Abstract

An axial flux motor can include a motor assembly including a motor shaft, a stator assembly, and a rotor assembly. The stator assembly can include a plurality of stator cores around which coils are wound, wherein one or more of the stator cores includes a stator body having an internal fluid passage for receiving a cooling fluid.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of U.S. Patent Application Serial No. 62 / 979,971, filed February 21, 2020, and U.S. Patent Application Serial No. 62 / 979,849, filed February 21, 2020, the disclosures of which are incorporated herein by reference in their entirety. Technical Field

[0003] This disclosure generally relates to electric motors and systems and methods for cooling electric motors. Background Technology

[0004] More-electric and all-electric aircraft are becoming increasingly relevant in the aerospace industry. Due to the growing demand for more-electric / all-electric aircraft, electric drive systems (EDS), including electric motors and electric drives, are receiving increasing attention in aerospace applications. To enhance the design of these new aircraft, the power density of electric machines is becoming a crucial factor due to weight / volume constraints associated with air travel. Achieving higher current-to-weight ratio and current-to-volume ratio targets is a real challenge. One of the obstacles to address in high-power-density machines is heat dissipation.

[0005] Figure 1 An exemplary thermal management arrangement for an existing system 50 is shown, comprising an electric motor 52 connected in series with a separate gear train 54, a propeller 56, or another load source using a motor shaft. An electric drive 58 controls the speed and / or torque applied to the motor shaft by the electric motor 52 based on the voltage and / or current input of the electric drive 58. The electric motor 52 is thermally managed using a separate coolant pump 60 and a separate heat exchanger 62. The coolant pump 60 drives coolant from the electric drive 58 to absorb heat from the electric drive 58, to the electric motor 52 to absorb heat from the electric motor 52, and to the heat exchanger 62 to dissipate the absorbed heat.

[0006] Coolant, driven by pump 60, travels through external piping connecting various components. In some examples, the coolant travels along circulation piping path 64 from pump 60 to electric drive 58, to electric motor 52, and then to heat exchanger 62. In other examples, the coolant travels along separate piping paths between pump 60 and the various components 58, 52, 62. External piping needs to be fitted to each component to connect to internal coolant paths (e.g., tanks) within the component. Furthermore, sufficient coolant must be supplied to traverse the distances between components and circulate within the components.

[0007] Improvements are expected. Summary of the Invention

[0008] An axial flux motor may include a motor assembly comprising a motor shaft, a rotor assembly, and a stator assembly, the stator assembly including a plurality of stator cores around which coils are wound, wherein one or more of the stator cores include a stator body having internal fluid channels for receiving cooling fluid.

[0009] In some examples, the internal fluid channels of the stator body include multiple fluid channels.

[0010] In some examples, the internal fluid channels extend to the fluid inlet and fluid outlet located on the outer surface of the stator body.

[0011] In some examples, the outer surface of the stator body is the end surface of the stator body.

[0012] In some examples, the internal fluid channels extend to the fluid inlet located on the outer surface of the stator body.

[0013] In some examples, the internal fluid channels extend to multiple outlet ends located on one or more sides of the stator body.

[0014] In some examples, the motor assembly also includes a pump for delivering cooling fluid into the internal fluid passage.

[0015] In some examples, the motor assembly also includes a reservoir for collecting cooling fluid discharged from multiple outlet ports.

[0016] The stator assembly may include a plurality of stator cores around which coils are wound, wherein one or more of these stator cores include a stator body having internal fluid channels for receiving cooling fluid.

[0017] In some examples, the internal fluid channels of the stator body include multiple fluid channels.

[0018] In some examples, the internal fluid channels extend to the fluid inlet and fluid outlet located on the outer surface of the stator body.

[0019] In some examples, the outer surface of the stator body is the end surface of the stator body.

[0020] In some examples, the internal fluid channels extend to the fluid inlet located on the outer surface of the stator body.

[0021] In some examples, the internal fluid channels extend to multiple outlet ends located on one or more sides of the stator body.

[0022] In some examples, the motor assembly also includes a pump for delivering cooling fluid into the internal fluid passage.

[0023] In some examples, the motor assembly also includes a reservoir for collecting cooling fluid discharged from multiple outlet ports.

[0024] A method for cooling a stator assembly of an electric motor may include delivering cooling fluid to a plurality of stator cores around which coils are wound, and guiding the cooling fluid through internal channels in the stator cores.

[0025] In some examples, cooling fluid is discharged from internal channels onto the coil.

[0026] In some examples, pumps are used to perform the delivery step.

[0027] In some examples, a pump driven by an electric motor is used to perform the delivery step.

[0028] The motor assembly may include: a motor shaft; a rotor assembly; a stator assembly including at least one stator core around which coils are wound; and an intermediate cooling layer disposed between the at least one stator core and the coils, wherein the intermediate cooling layer includes a stator body having internal fluid channels for receiving cooling fluid.

[0029] In some examples, the internal fluid channels include multiple fluid channels.

[0030] In some examples, the internal fluid channels extend to the fluid inlet and fluid outlet located on the outer surface of the intermediate cooling layer.

[0031] In some examples, the intermediate cooling layer includes an extension that extends between the individual windings of the coil.

[0032] In some examples, the internal fluid channels extend to the fluid inlet located on the outer surface of the intermediate cooling layer.

[0033] In some examples, the internal fluid channels extend to multiple outlets located on one or more sides of the intermediate cooling layer.

[0034] In some examples, the motor assembly also includes a pump for delivering cooling fluid into the internal fluid passage.

[0035] In some examples, the intermediate cooling layer is formed of a thermally conductive material.

[0036] A stator assembly for an electric motor may include: at least one stator core around which a coil is wound; and an intermediate cooling layer disposed between the at least one stator core and the coil, wherein the intermediate cooling layer includes a stator body having internal fluid channels for receiving cooling fluid.

[0037] In some examples, the internal fluid channels include multiple fluid channels.

[0038] In some examples, the internal fluid channels extend to the fluid inlet and fluid outlet located on the outer surface of the intermediate cooling layer.

[0039] In some examples, the intermediate cooling layer includes an extension that extends between the individual windings of the coil.

[0040] In some examples, the internal fluid channels extend to the fluid inlet located on the outer surface of the intermediate cooling layer.

[0041] In some examples, the internal fluid channels extend to multiple outlet ends located on one or more sides of the intermediate cooling layer.

[0042] In some examples, the motor assembly also includes a pump for delivering cooling fluid into the internal fluid passage.

[0043] In some examples, the intermediate cooling layer is formed of a thermally conductive material.

[0044] A method for cooling an electric motor may include delivering cooling fluid to at least one stator core around which a coil is wound, and guiding the cooling fluid through internal channels disposed between the at least one stator core and the coil.

[0045] In some examples, the method also includes guiding cooling fluid through multiple intermediate cooling layers associated with multiple stator cores.

[0046] In some examples, pumps are used to perform the delivery step.

[0047] In some examples, a pump driven by an electric motor is used to perform the delivery step.

[0048] An electric motor assembly may include: a motor shaft; a rotor assembly; a stator assembly including at least one stator core around which coils are wound and embedded in a thermally conductive material, the stator assembly defining a ring having a radially inner side and a radially outer side; and a first internal fluid channel defined within the thermally conductive material and located at one of the radially inner and radially outer sides of the stator assembly, the first internal fluid channel being configured to receive cooling fluid.

[0049] In some examples, the first internal fluid channel includes multiple internal fluid channels.

[0050] In some examples, the first internal fluid channel is located radially inside the stator assembly.

[0051] In some examples, the first internal fluid passage is located radially outside the stator assembly.

[0052] In some examples, the motor also includes a second internal fluid channel defined within a thermally conductive material and located either radially inside or radially outside the stator assembly, the second internal fluid channel being configured to receive cooling fluid.

[0053] In some examples, the first internal fluid channel and the second internal fluid channel each include multiple internal fluid channels.

[0054] In some examples, the first internal fluid channel is located radially inside the stator assembly, and the second internal fluid channel is located radially outside the stator assembly.

[0055] In some examples, the first internal fluid passage and the second internal fluid passage each include at least one fluid inlet and at least one fluid outlet.

[0056] In some examples, the motor assembly also includes a pump for delivering cooling fluid to a first internal fluid passage.

[0057] In some examples, the thermally conductive material is epoxy resin.

[0058] A stator assembly for an electric motor may include: at least one stator core around which coils are wound; and a stator assembly including at least one stator core around which coils are wound and embedded in a thermally conductive material, the stator assembly defining a ring having a radially inner side and a radially outer side; and a first internal fluid channel defined within the thermally conductive material and located at one of the radially inner and radially outer sides of the stator assembly, the first internal fluid channel being configured to receive cooling fluid.

[0059] In some examples, the first internal fluid channel includes multiple internal fluid channels.

[0060] In some examples, the first internal fluid channel is located radially inside the stator assembly.

[0061] In some examples, the first internal fluid passage is located radially outside the stator assembly.

[0062] In some examples, the stator assembly includes a second internal fluid channel defined within a thermally conductive material and located either radially inner or radially outer of the stator assembly, the second internal fluid channel being configured to receive cooling fluid.

[0063] In some examples, the first internal fluid channel and the second internal fluid channel each include multiple internal fluid channels.

[0064] In some examples, the first internal fluid channel is located radially inside the stator assembly, and the second internal fluid channel is located radially outside the stator assembly.

[0065] In some examples, the first internal fluid passage and the second internal fluid passage each include at least one fluid inlet and at least one fluid outlet.

[0066] In some examples, the thermally conductive material is epoxy resin.

[0067] A method for cooling a stator assembly of an electric motor may include: delivering cooling fluid to at least one stator core, with a coil wound around the at least one stator core; and guiding the cooling fluid through one or more internal channels of a thermally conductive material, with the coil embedded within the one or more internal channels.

[0068] In some examples, pumps are used to perform the delivery step.

[0069] In some examples, a pump driven by an electric motor is used to perform the delivery step.

[0070] An electric motor assembly may include a motor shaft, a stator assembly, and a rotor assembly, and a cooling jacket surrounding the stator assembly. The cooling jacket includes: an inner wall radially inward toward the stator assembly; and a relative outer wall radially outward; a circumferential first internal fluid passage for allowing cooling fluid to be pumped through the interior of the cooling jacket; an internal fluid passage disposed between the inner and outer walls and extending between an inlet and an outlet; and a first end plate covering and contacting at least a portion of a first end in the case of the stator assembly, the first end plate including a second internal fluid passage in fluid communication with the first circumferential fluid passage, thereby allowing cooling fluid to be pumped through the interior of the first end plate.

[0071] In some examples, the end plate is located between the stator assembly and the magnets associated with the motor assembly.

[0072] In some examples, the second internal fluid channel includes multiple internal channels.

[0073] In some examples, the end plate is in direct contact with the end face of one or more stator cores associated with the stator assembly.

[0074] In some examples, the second internal channel of the endplate is in fluid communication with the circumferential first internal channel at multiple connection points.

[0075] In some examples, the end plates and cooling jackets are made of the same type of material.

[0076] In some examples, the end plates and cooling jackets are made of different types of materials.

[0077] In some examples, the motor assembly includes an axial flux motor assembly.

[0078] In some examples, the motor assembly also includes a pump for delivering cooling fluid into the internal fluid passage.

[0079] In some examples, the pump is driven by a motor shaft.

[0080] A cooling system for an electric motor assembly may include a cooling jacket for surrounding a stator assembly, the cooling jacket including: an inner wall facing radially inward; and an opposing outer wall facing radially outward; a circumferential first internal fluid passage for allowing cooling fluid to be pumped through the interior of the cooling jacket; an internal fluid passage disposed between the inner and outer walls and extending between an inlet and an outlet; and a first end plate configured to cover at least a portion of the stator assembly and contact at least a portion of the stator assembly, the first end plate including a second internal fluid passage in fluid communication with the first circumferential fluid passage, thereby allowing cooling fluid to be pumped through the interior of the first end plate.

[0081] In some examples, the second internal fluid channel includes multiple internal channels.

[0082] In some examples, the second internal channel of the endplate is in fluid communication with the circumferential first internal channel at multiple connection points.

[0083] In some examples, the end plates and cooling jackets are made of the same type of material.

[0084] In some examples, the end plates and cooling jackets are made of different types of materials.

[0085] A method for cooling a stator assembly of an electric motor may include the steps of: delivering and returning cooling fluid to a cooling jacket surrounding the stator assembly; and delivering and returning cooling fluid to an end plate in direct contact with an end face of the stator assembly, such that cooling is provided to the stator assembly at least on both sides of the stator assembly.

[0086] In some examples, the delivery steps include guiding cooling fluid from the internal channels of the cooling jacket to the internal channels of the end plate and from the internal channels of the end plate.

[0087] In some examples, pumps are used to perform the delivery step.

[0088] In some examples, a pump driven by an electric motor is used to perform the delivery step.

[0089] In some examples, the cooling fluid is one of oil, ethylene glycol, and water.

[0090] An electric motor assembly unit may include an electric motor extending along a longitudinal axis between a first axial end and a second axial end, the electric motor including: a stator assembly; a rotor assembly that rotates relative to the stator assembly; and a motor shaft operatively coupled to the rotor assembly, the motor shaft extending along the longitudinal axis of the electric motor beyond the first axial end; and a heat exchanger mounted to the electric motor for being disposed between the first axial end and the second axial end of the electric motor and structurally supported by the electric motor, the heat exchanger including an exchanger housing and coolant paths disposed within the exchanger housing, the exchanger housing extending radially outward from the electric motor.

[0091] In some examples, the heat exchanger surrounds the stator assembly around the longitudinal axis of the motor.

[0092] In some examples, the heat exchanger extends only a portion of the circumference of the stator assembly.

[0093] In some examples, the coolant path within the heat exchanger is a first coolant path, and the first coolant path is fluidly connected to a second coolant path within the motor.

[0094] In some examples, the second coolant path includes a groove extending through a cooling jacket surrounding the rotor assembly and the stator assembly.

[0095] In some examples, the second coolant path includes a slot that extends through a portion of the stator core of the stator assembly.

[0096] In some examples, the second coolant path extends to the coolant pump installed in the electric motor.

[0097] In some examples, the coolant pump is mounted to the motor shaft.

[0098] In some examples, the coolant pump is at least partially recessed into the motor housing that covers the rotor assembly.

[0099] In some examples, the motor assembly also includes a planetary gear train disposed within the motor, such that the planetary gear train is enclosed within a stator assembly and a rotor assembly, wherein the planetary gear train includes: a sun gear; a carrier coupled to a plurality of planetary gears meshing with the sun gear; and an outer ring having inwardly facing teeth meshing with the planetary gears, wherein at least one of the sun gear, the carrier, and the outer ring rotates in unison with a drive shaft.

[0100] In some examples, the motor assembly also includes a third coolant path that supplies coolant to the planetary gear train, the third coolant path being fluidly connected to a coolant path that extends through the exchanger housing.

[0101] In some examples, a coolant pump is mounted to an electric motor, and the coolant pump is coupled to the first gear stage of a planetary gear train, which rotates at a different speed than the drive shaft.

[0102] In some examples, the coolant pump is mounted to the drive shaft.

[0103] In some examples, the electric drive is located on the outer surface of the stator assembly.

[0104] In some examples, the coolant path is fluidly connected to the corresponding coolant path of the electric drive.

[0105] In some examples, the electric motor includes an axial flux motor.

[0106] An aircraft propulsion system may include: a propeller operatively coupled to a drive shaft extending along a longitudinal axis; an electric motor including a rotor assembly that rotates relative to a stator assembly to rotate the drive shaft; a heat exchanger mounted to the electric motor such that the heat exchanger extends radially outward from the electric motor and extends along the longitudinal axis between opposing first and second axial ends; and a flow path along which airflow generated by the propeller flows to the first axial end of the heat exchanger.

[0107] In some examples, the motor is one of a plurality of motors that apply torque to the drive shaft, each of which is aligned along a longitudinal axis and operatively coupled to the drive shaft; and the heat exchanger is one of a plurality of heat exchangers, each of which is mounted to a corresponding one of the motors.

[0108] In some examples, each of the heat exchangers extends radially outward from the circumferential portion of the corresponding motor, wherein the heat exchangers are circumferentially staggered such that the corresponding first axial end of each of the heat exchangers is accessible to the flow path.

[0109] In some examples, a nacelle is provided that surrounds a portion of the drive shaft and is spaced apart from the propeller along the longitudinal axis of the drive shaft, with an electric motor and a heat exchanger located within the nacelle, wherein the flow path includes a first flow path extending into the nacelle and a second flow path extending around the nacelle, the first flow path extending to a first axial end of the heat exchanger.

[0110] In some examples, the heat exchanger and the electric motor share a coolant path.

[0111] In some examples, the planetary gear system is housed within the electric motor, and the electric motor and the planetary gear system share the coolant path.

[0112] An electric motor assembly unit may include an electric motor, a planetary gear train, and a coolant pump. The electric motor extends along a longitudinal axis between a first axial end and a second axial end. The electric motor includes: a stator assembly; a rotor assembly that rotates relative to the stator assembly; a motor shaft operatively coupled to the rotor assembly; and a motor housing surrounding the rotor assembly and the stator assembly. The motor shaft extends along the longitudinal axis of the electric motor beyond the first and second axial ends. The planetary gear train is disposed within the motor housing between the first and second axial ends of the electric motor. The planetary gear train includes: a sun gear; a carrier coupled to a plurality of planetary gears meshing with the sun gear; and an outer ring having inwardly facing teeth meshing with the planetary gears. Each of the sun gear, the carrier, and the outer ring forms a corresponding gear stage of the planetary gear train, wherein at least one of the sun gear, the carrier, and the outer ring rotates in unison with a drive shaft. The coolant pump is mounted to the electric motor and coupled to another gear stage of the planetary gear train that rotates at a different speed than the drive shaft.

[0113] In some examples, a coolant path is provided that extends from the coolant pump through the electric motor to the rotary gear train, wherein the coolant path is at least substantially contained within the motor housing of the electric motor.

[0114] In some examples, the coolant pump is located outside the motor housing at the first axial end of the motor.

[0115] In some examples, the motor housing includes a heat exchanger and a coolant pump integrated with the heat exchanger.

[0116] Various other aspects will be set forth in the description listed below. Aspects of the invention relate to various features and combinations of features. It should be understood that the foregoing general description and the following detailed description are merely exemplary and illustrative, and do not limit the broad inventive concept on which the examples disclosed herein are based. Attached Figure Description

[0117] Several aspects of this disclosure are illustrated in conjunction with the accompanying drawings, which are included in and form part of this specification.

[0118] Figure 1 This is a schematic diagram of an exemplary prior art system for providing thermal management to an electric motor.

[0119] Figure 2 This is a perspective view of an exemplary motor assembly unit including a motor and a heat exchanger configured according to the principles of this disclosure.

[0120] Figure 3 yes Figure 2 The side front view of the motor assembly unit shown.

[0121] Figure 4 It is along Figure 2 A perspective view of an exemplary cross-section of the motor assembly unit taken by line 4-4.

[0122] Figure 5 Is it suitable for and Figure 2 A perspective view of an exemplary stator assembly used in conjunction with an electric motor.

[0123] Figure 6 Is it suitable for and Figure 5 A perspective view of an exemplary stator core used in conjunction with stator components.

[0124] Figure 7 Is it suitable for and Figure 5 A perspective view of an exemplary coil used in conjunction with a stator assembly.

[0125] Figure 8 This is a perspective view of an exemplary electric motor assembly unit, except that the motor shaft is defined by a gear train mounted within the electric motor, and the electric motor assembly unit is... Figure 2 The motor component units are basically the same.

[0126] Figure 9 Is it suitable for and Figure 2 A perspective view of an exemplary magnetic rotor used in conjunction with the rotor assembly of an electric motor.

[0127] Figure 10 yes Figure 9 A perspective view of an exemplary permanent magnet of a magnetic rotor.

[0128] Figure 11 This is a partial view of the cross-section of the motor assembly unit, which covers an exemplary coolant path.

[0129] Figure 12 It is installed within the cabin of an exemplary aircraft propulsion system and constructed in accordance with the principles of this disclosure. Figure 2 A schematic diagram of the motor assembly unit.

[0130] Figure 13 Showing settings Figure 12 The cabin contains multiple electric motors, each with a corresponding heat exchanger that is circumferentially staggered relative to another heat exchanger.

[0131] Figure 14 It is a section taken along line 14-14. Figure 13 A partial view of the cross-section of the drive shaft.

[0132] Figure 15 It is a section taken along line 4-4. Figure 2 A cross-sectional view of the motor assembly unit.

[0133] Figure 16 Is it suitable for and Figure 2 A perspective view of a portion of a planetary gear system used together with an electric motor assembly unit.

[0134] Figure 17 This is a schematic diagram of an exemplary end view of another motor assembly unit constructed in accordance with the principles of this disclosure.

[0135] Figure 18 yes Figure 2 A schematic diagram of the rotating gear system and related components of the electric motor assembly unit.

[0136] Figure 19 yes Figure 2 A schematic diagram of the alternative arrangement of the rotating gear system and related components of the electric motor assembly unit.

[0137] Figure 20 yes Figure 2 A schematic diagram of the cooling system for the motor assembly unit.

[0138] Figure 21 yes Figure 6 The diagram shows a perspective view of a general type of stator core, which also includes internal channels.

[0139] Figure 22 yes Figure 6 The view shown is of a general type of stator core, which also includes internal channels and spray channels.

[0140] Figure 23 yes Figure 22 A cross-sectional view of the stator core, showing Figure 1 The installation state inside the axial flux motor.

[0141] Figure 24 yes Figure 6 The diagram shows a perspective view of a general type of stator core and coil, with an intermediate cooling layer between them.

[0142] Figure 25 yes Figure 24 A schematic cross-sectional view of the stator core, coils, and intermediate cooling layer shown.

[0143] Figure 26 yes Figure 4 and Figure 11 A schematic cross-sectional view of a general type of stator assembly is shown, in which cooling channels are shown as the radially inner and radially outer sides adjacent to the coils.

[0144] Figure 27 yes Figure 2 A schematic partial cross-section of the motor assembly, in which an end plate with internal cooling channels is provided.

[0145] Figure 28 yes Figure 27 The schematic partial cross-section of the component shown also illustrates the cooling channel. Detailed Implementation

[0146] Various examples will be described in detail with reference to the accompanying drawings, wherein the same reference numerals denote the same parts and components in several views. The reference numerals to the various examples do not limit the scope of the appended claims. Furthermore, any examples set forth in this disclosure are not intended to be limiting, but merely illustrate some of the many possible examples of the appended claims. Referring to the accompanying drawings, the same reference numerals correspond to the same or similar parts throughout the various drawings.

[0147] General Motor Description

[0148] Reference will now be made in detail to exemplary aspects of this disclosure as illustrated in the accompanying drawings. Throughout the drawings, the same reference numerals will be used wherever possible to denote the same or similar parts.

[0149] This disclosure relates to a motor assembly unit 100 comprising a motor 110 having one or more integrated thermal management components. The motor assembly unit 100 extends along a longitudinal axis L between opposing first axial ends 102 and second axial ends 104. In the illustrated example, the motor assembly unit 100 has a generally circular cross-sectional region with a diameter varying along the longitudinal axis L. However, in other examples, the motor assembly unit 100 may have other cross-sectional shapes (e.g., rectangular, elliptical, etc.). In some embodiments, the motor 110 is an axial flux motor 110. In other embodiments, the motor 110 is a radial flux motor.

[0150] like Figures 2 to 4 As shown, the electric motor 110 includes a motor shaft 112, a stator assembly 114, and a rotor assembly 116. The motor shaft 112 extends along the longitudinal axis L of the motor assembly unit 100. The rotor assembly 116 is adapted to rotate relative to the stator assembly 114 about the longitudinal axis L. The motor shaft 112 is operatively coupled to the rotor assembly 116 to rotate about the longitudinal axis L as the rotor assembly 116 rotates. In some embodiments, the motor shaft 112 rotates in unison with the rotor assembly 116. In other embodiments, the motor shaft 112 rotates with a different gear sequence than the rotor assembly 116. In some embodiments, a motor housing 118 encloses the stator assembly 114 and the rotor assembly 116. An end 113 of the motor shaft 112 projects outwardly from the motor housing 118 along the axis of rotation L.

[0151] Figures 5 to 7An example stator assembly 114 suitable for use with the electric motor 100 described herein is shown. The stator assembly 114 includes a plurality of electromagnets 120 circumferentially spaced about a rotation axis L. Each electromagnet 120 includes a stator core 122 around which a coil 124 is wound (e.g., as shown in the diagram). Figure 7 (The copper winding shown). Figure 6 Stator core 122 is shown. Each stator core 122 includes a core body 126 extending along a core axis 128 between first and second opposing axial ends 130, 132 of the core body 126. The first axial end 130 defines a first end face 134 facing a first axial direction 136, and the second axial end 132 defines a second end face 135 facing a second axial direction 138 opposite to the first axial direction 136. A coil 124 is wound around the core axis 128 and located between the first axial end 136 and the second axial end 138 of the core body 126. The first axial end 130 and the second axial end 132 of each stator core 122 are adapted to define opposite magnetic poles of each corresponding electromagnet 120.

[0152] Figures 8 to 9 An exemplary rotor assembly 116 suitable for use with the electric motor 100 described herein is shown. The rotor assembly 116 includes a first magnetic rotor 140 and a second magnetic rotor 142 disposed at opposite axial ends of a stator assembly 114. The first magnetic rotor 140 and the second magnetic rotor 142 are adapted to rotate coherently about a rotation axis L. In some specific embodiments, the first magnetic rotor 140 and the second magnetic rotor 142 are identical to each other.

[0153] Each of the magnetic rotors 140 and 142 is supported by a corresponding rotor carrier 144, which includes a rotor plate 146 (e.g., a rotor flange) projecting radially outward from a central hub portion 148. The central hub portions 148 of the first magnetic rotor 140 and the second magnetic rotor 142 are preferably fastened (e.g., bolted) together to define the hub of the rotor assembly 116. The hub can be mounted to rotate relative to the stator core 122 via one or more rotary bearings 150. As depicted, the rotary bearings 150 can be mounted between the hub and a sleeve 152 fixed at the inner diameter of the stator assembly 114. In one example, the electromagnet 120 can be secured around the sleeve 152 by an adhesive material such as thermally conductive epoxy resin.

[0154] In some embodiments, the motor shaft 112 is coupled to the rotor assembly 116. For example, the motor shaft 112 may include a flange 113 that is fastened (e.g., bolted) to the hub 148 of the rotor assembly 116. In such embodiments, it should be understood that the motor shaft 112 and the rotor assembly 116 are adapted to rotate relative to each other about a rotational axis L relative to the stator assembly 114. In other embodiments, a gear train (e.g., a planetary gear train as will be described in more detail herein) operably couples the motor shaft 112 to the hub 148 such that the motor shaft 112 rotates at a different speed and / or torque than the hub 148.

[0155] Figure 9 Exemplary specific embodiments of magnetic rotors suitable for use as a first magnetic rotor 140 and / or a second magnetic rotor 142 are shown. Magnetic rotors 140, 142 include a plurality of permanent magnets 154 carried by rotor plates 148 of respective carriers 144 (e.g., see...). Figure 10 The permanent magnets 154 are circumferentially spaced around the rotation axis L. The permanent magnets 154 of the first magnetic rotor 140 have a first permanent magnet end face 156 positioned opposite a first axial end face 134 of the stator core 122. The permanent magnet end face 156 and the first axial end face 134 of the stator core 122 are separated by a first air gap. The permanent magnets 154 of the second magnetic rotor 142 have a second permanent magnet end face positioned opposite a second axial end face of the stator core 122. The second permanent magnet end face and the second axial end face of the stator core 122 are separated by a second air gap.

[0156] Return to reference Figures 2 to 4 The motor housing 118 encloses the stator assembly 114 and the rotor assembly 116 to form the exterior of the motor assembly unit 100. The motor housing 118 includes a first axial wall 160 and a second axial wall 162, which respectively cover the carrier 144 of the first magnetic rotor 140 and the second magnetic rotor 142. In some examples, the first axial wall 160 and the second axial wall 162 preferably have a metallic (e.g., aluminum) construction. The first axial wall 160 defines a central opening 164 through which the end 113 of the motor shaft 112 extends. The motor housing 118 also includes a circumferential wall extending between the first axial wall 160 and the second axial wall 162. In one example, the second axial wall 162 may be integrally connected to the circumferential wall, while the first axial wall 160 may be configured as a removable axial end cap.

[0157] In some examples, the heat exchanger 166 shares structural support with the motor 110, thereby reducing the overall weight of the motor assembly unit 100. For example, the heat exchanger 166 may be structurally supported by the motor 110 (e.g., by the stator assembly 114 and / or by the circumferential wall of the motor housing 118). In some examples, the heat exchanger 166 forms a circumferential wall of the motor housing 118, thereby reducing the number of parts to be manufactured and assembled in the system and reducing the overall weight of the system.

[0158] Figures 12 to 14 An exemplary environment (e.g., aircraft propulsion system 200) is shown, in which electric motor assembly unit 100 can be utilized. Propulsion system 200 includes a propeller 202 or other thrusters operatively coupled to a drive shaft 204 driven by electric motor assembly unit 100. In some specific embodiments, electric motor assembly unit 100 is disposed within the interior 208 of nacelle 206 or within another body disposed around drive shaft 204. When propeller 202 rotates, propeller 202 generates airflow that produces thrust for the aircraft.

[0159] In the example shown, a first portion F1 of the airflow generated by propeller 202 enters the opening 210 of nacelle 206 and flows toward motor assembly unit 100. Motor assembly unit 100 is disposed within nacelle 206 concurrently with the first portion F1 of the airflow. Therefore, the first portion F1 of the airflow assists heat exchanger 166 in dissipating heat by flowing through heat exchanger 166 and carrying heat away from coolant path 172, as discussed in more detail below. A second portion F2 of the airflow generated by propeller 202 flows around nacelle 206. In some examples, the first portion F1 is substantially smaller than the second portion F2.

[0160] like Figure 13 and Figure 14 As shown, multiple electric motors 110 can cooperate to apply torque to the drive shaft 204. Each electric motor 110 may have a corresponding heat exchanger 166. In some specific embodiments, the heat exchangers 166 may be arranged to allow a first portion F1 of the airflow to reach each of the heat exchangers 166 (e.g., arranged such that no heat exchanger 166 obstructs any of the other heat exchangers 166). Figure 13 As shown, the first motor 110a is arranged in accordance with the second motor 110b and the third motor 110c. Each of the motors 110a-110c has a corresponding heat exchanger 166a-166c, which extends only along the circumferential portion of the motors 110a-110c. Figure 14 As shown, heat exchangers 166a, 166b, and 166c can be circumferentially staggered, so that the axial end face of each heat exchanger 166a, 166b, and 166c can be approached by the first airflow F1.

[0161] refer to Figure 15 , Figure 16 and Figure 18 The coolant pump 180 can be integrated into the motor assembly unit 100. For example, the coolant pump 180 can be directly mounted to the motor 100 (e.g., to the motor shaft 112). In some embodiments, the coolant pump 180 can be operated by rotating the motor shaft 112. In such embodiments, the coolant pump 180 drives the coolant based on the speed at which the rotor assembly 116 rotates relative to the stator assembly 114. However, in other embodiments, the coolant pump 180 can be operatively coupled to the rotor assembly 116 via a gear train to change the torque and / or speed applied to the coolant pump 180.

[0162] In some embodiments, the coolant pump 180 may be operatively coupled to the rotor assembly 116 via a planetary gear train 190. The planetary gear train 190 includes a sun gear 192 that meshes with a plurality (e.g., three) of planetary gears 194 surrounding the sun gear 192. The planetary gears 194 mesh with internal teeth 195 of a surrounding ring. In the illustrated example, the internal teeth 195 are disposed on an inner surface of a sleeve or hub region defined by the rotor assembly 116, within which the planetary gear train 190 is located. In some embodiments, the planetary gears 194 are held in position around the sun gear 192 by a gear housing 196 relative to which they rotate. The gear housing 196, which serves as a carrier for the planetary gears 194, may be rotatably fixed relative to the stator assembly 114 and / or the motor housing 118.

[0163] In some embodiments, the planetary gear train 190 is disposed within the electric motor 110. For example, the planetary gear train 190 may be disposed within the rotor assembly 116. In some examples, the central hub portion 148 of the magnetic rotors 140, 142 may include internal teeth to form a surrounding ring of the planetary gear train 190. Therefore, the sun gear 192 rotates at a different speed and / or with a different torque than the rotor assembly 116. If the motor shaft 112 is directly coupled to the rotor assembly 116, the sun gear 192 rotates at a different speed and / or with a different torque than the motor shaft 112.

[0164] In some embodiments, the sun gear 192 may include a shaft 198 extending outward from the sun gear 192 along its axis of rotation. In the example, the axis of rotation of the sun gear 192 is the longitudinal axis L of the motor assembly unit 100. In some examples, the shaft 198 is coupled to a coolant pump 180 (e.g., see...). Figure 15For example, coolant pump 198 may be coupled to sun gear 192 to optimize pump rotation speed for efficiency and weight. In such an example, motor shaft 112, coupled to rotate in unison with rotor assembly 116, extends from the opposite side of motor 110 from coolant pump 180 (see, for example, see...). Figure 4 ).

[0165] In other embodiments, the coolant pump 180 may be coupled to rotate in unison with a carrier rotated by the planetary gear 194. In some examples, the coolant pump 180 may be embedded within the motor shaft 112. In such examples, the motor shaft 112 may be defined by the shaft 198 of the sun gear 192 (see, for example, see...). Figure 8 In other embodiments, the coolant pump 180 may be coupled to rotate in unison with the rotor assembly 116, such as... Figure 11 and Figure 19 As shown. In this configuration, the planetary gear train 190 can be used to interconnect the rotor assembly 116 with the motor shaft 112, such that the output speed / torque of the motor shaft 112 is the same as that shown. Figure 11 and Figure 19 The output speed / torque of the rotor assembly 116 shown is different.

[0166] In some embodiments, the electric actuator 178 for the electric motor 110 may be integrated with the electric motor assembly unit 100. In such embodiments, the electric actuator 178 may share thermal management with the electric motor 110. In some examples, the electric actuator 178 may be positioned toward the inner circumferential surface of the heat exchanger 166. Coolant directed to the heat exchanger 166 may collect heat via the electric actuator. In other examples, the electric actuator 178 may be mounted to a cooling jacket extending over a portion of the circumference of the electric motor 110 (e.g., see...). Figure 17 The heat exchanger 166 may extend over the rest of the circumferential portion of the electric motor 110. In some examples, the electric motor housing 118 may include a cover extending over the electric drive 178 between the circumferential edges of the heat exchanger 166.

[0167] Examples of how an electric drive 178 can be adapted to be mounted externally to an electric motor 110 are shown and described in U.S. Provisional Application Serial No. 62 / 946,172, filed December 10, 2019, entitled “Cooling Jacket Integrated with Cold Plate”, and PCT Application Serial No. PCT / EP2020 / 025570, filed December 10, 2020. The full disclosure of these applications is incorporated herein by reference.

[0168] Figure 11 and Figure 20 cooling system

[0169] refer to Figure 11 and Figure 20 A cooling system 170 is shown, in which a coolant pump 180 circulates a working fluid (e.g., water, glycol, and oil) between heat exchangers 166. The working fluid is cooled by air flowing through the heat exchangers to various components within the motor assembly 110, and absorbs heat from the components. In one aspect, the heat exchanger 166 has an exchanger housing 168 and a coolant path 172 arranged within the exchanger housing 168. In some embodiments, one or more cooling plates or fins 171 form part of the heat exchanger 166, and the coolant path 172 delivers heated coolant to the cooling plates or fins 171. In other embodiments, the coolant path 172 may extend through a monolithic structure (e.g., a corrugated structure) within the exchanger housing 168. In some examples, the monolithic structure forms the exchanger housing 168. In some embodiments, the heat exchanger 166 extends circumferentially around (e.g., the stator assembly 114) the entire motor 110. In other embodiments, the heat exchanger 166 may extend only a portion of the circumference. In such embodiments, a cooling jacket 167, including a circumferential internal channel 167a surrounding the stator assembly 114, may extend around the remainder of the circumference to form the motor housing 118. Additional details of the cooling jacket construction are further shown and described in U.S. Provisional Patent Application Serial No. 62 / 931,712, filed November 6, 2019, entitled “Axial Flux Motor with Cooling Jacket,” and PCT Application Serial No. PCT / EP2020 / 025497, filed November 6, 2020, the entire contents of which are incorporated herein by reference.

[0170] In some embodiments, coolant path 172 through heat exchanger housing 168 is fluidly connected to another coolant path 174 via motor 110, which directs coolant pump 180. In some examples, coolant path 174 extends through a slot defined in motor housing 118. In some examples, coolant path 174 extends through components contained within motor housing 118. Coolant pump 180 circulates coolant through coolant paths 172 and 174. Because heat exchanger 166 forms part of motor housing 118, coolant paths 172 and 174 are designed to be fluidly connected together within motor 110. In one aspect, coolant path 172 is used to dissipate heat from the working fluid flowing through it, while coolant path 174 is used to absorb heat from internal components of motor 110.

[0171] Containing coolant paths 172 and 174 within the motor assembly unit 100 eliminates the need for external piping and fittings between external pipes and various components. Furthermore, eliminating external piping and positioning it within the integrated unit reduces the amount of coolant required to traverse the paths. Reducing the required piping and coolant volume saves on costs associated with cooling the motor assembly unit 100. Additionally, reducing these components also reduces the weight associated with the motor assembly unit 100.

[0172] In one aspect, the coolant pump 180 is connected to coolant paths 172 and 174 via supply and return branches 172a, 172b, 174a, and 174b, which in turn connect to other supply and return branches to cool various components of the motor 110. In one example, the supply and return branches 172a, 172b, 174a, and 174b extend radially and / or circumferentially, allowing working fluid to be distributed throughout the motor 110. In another example, multiple supply and return branches 172a, 172b, 174a, and 174b are radially distributed at various locations within the motor 110, allowing working fluid to be distributed to various cooling circuits throughout the motor 110.

[0173] In one example, and as previously discussed, coolant path 172 defines a cooling circuit 220 connected to supply and return branches 172a, 172b, wherein the cooling circuit 220 is formed by a plurality of internal channels 220a defined within a heat exchanger 166 of motor 120. In one example, heat exchanger 166 is configured with fins, ribs, or other surface area maximizing features to allow air flowing through motor 110 to cool cooling heat exchanger 130, thereby aiding in the removal of heat from the working fluid within the internal channels 220a. Thus, heat exchanger 166 can be configured to function as an air-liquid heat exchanger.

[0174] In the illustrated example, cooling circuits 222, 224, 226, and 228 are also shown connected to supply and return branches 174a and 174b. As shown, cooling circuit 222 is shown as including an internal channel 222a adjacent to the inside of coil 124, allowing heat to be transferred from coil 124 to the working fluid. As shown, cooling circuit 224 is shown as including an internal channel 224a within and / or around each of the stator core bodies 122, allowing heat to be transferred from coil 124 to the stator core body 122 and then to the working fluid. As shown, cooling circuit 226 is shown as including an internal channel 226a adjacent to the outside of coil 124, allowing heat to be transferred from coil 124 to the working fluid. In one example, cooling circuit 224 and internal channel 226a are defined as the aforementioned cooling jacket 167 and internal channel 167a. As shown, cooling circuit 228a is illustrated as including an internal channel 228a adjacent to the outer side of the planetary gear train 190, allowing heat to be transferred from the planetary gear train 190 to the working fluid. When cooling circuits 222, 224, 226, 228 are connected to branches 174a, 174b, warm or heated working fluid can circulate from cooling circuits 222, 224, 226, 228 to cooling circuit 220, where the fluid can be cooled and then returned to circuits 222, 224, 226, 228 via pump 180. Although cooling system 110 is shown with paths 172, 174 and circuits 222, 224, 226, 228, other configurations include more or fewer circuits without departing from the concepts disclosed herein. For example, cooling system 170 may be provided with multiple branches arranged parallel to each other and connected to pump 180, for example, via manifolds, to reduce pressure drop losses of the cooling fluid. In one example, an external heat exchanger may be used in conjunction with or in place of cooling circuit 220. In some configurations, motor 110 may also be provided with a reservoir 175 connected to one or more return branches 172b, 174b, thereby collecting heated cooling fluid, such as spray fluid, and returning it to pump 180.

[0175] Figure 21 Stator cooling structure

[0176] refer to Figure 21 The stator core body 126 is shown separately to illustrate the features of the stator core 122 that forms part of the cooling circuit 224. As shown, an internal channel 224a of the cooling circuit 224 is guided through the stator core body 126, wherein an inlet end 224b and an outlet end 224c extend through an end face 135. The cooling circuit 224 includes additional paths or branches extending between the inlet end 224b and the outlet end 224c of each stator core 122 and branches 174a, 174b, such as... Figure 11and Figure 20 As shown schematically, the cooling circuit 224 includes multiple sub-circuits associated with each stator core body 126, wherein inlet 224b and outlet 224c are connected together such that pumped working fluid is delivered to each stator core body 126. Although Figure 21 The arrangement of channel 224a as a single U-shaped channel is schematically shown; however, it should be understood that channel 224a may include multiple channels provided in any number of various shapes, such as a serpentine shape. Channel 224a may further include multiple inlet ends 224b and outlet ends 224c. Furthermore, channel 224a may include a large cavity within the stator core body 126, such that the interior of the stator core body 126 is substantially filled with cooling fluid. By providing one or more internal channels 224a within the stator core body 126 of the stator assembly 114, the working fluid can remove heat very close to the heating coils 124 to improve the cooling of the motor 110. It should be noted that the shape of the stator core body 126 and the number of stator core bodies 126 provided in the motor 110 may differ from those shown in the figures without departing from the concept presented herein.

[0177] Figure 21 The stator core body 126 can be manufactured in various ways. For example, a solid stator core body 126, such as a solid metal stator core body, can be initially formed and subsequently machined to form internal channels 224a, inlet 224b, and outlet 224c using a drill bit or other tools. The stator core body 126 can also be formed using additive manufacturing techniques.

[0178] Figure 22 and Figure 23 Stator cooling structure

[0179] refer to Figure 22 A separate stator core 122 is shown to illustrate additional features of the stator core body 126 that forms part of the cooling circuit 224. Figure 23 Show Figure 22 The diagram shows a cross-sectional view of the stator core body 126 in an installation environment, with coils 124 wound around the stator core body 126. Figure 21 The stator core 122 shown is the same. Figure 22 and Figure 23The stator core 122 includes an internal channel 224a. As shown, in this example, the internal channel 224a includes four internal channels extending to an inlet end 224b on the end face 135 of the stator core body 126. In an alternative configuration, the channel 224a may be internally connected within the stator core body 126, such that only a single inlet 224b is generated. As shown, the channel 224a is also provided with a plurality of outlet ends 224c arranged along the length of the channel 224a and passing through opposite sides 126a, 126b of the stator core body 38. The outlet ends 224c may be provided on one side 126a, 126b or on both sides 126a, 126b of the stator core body 126. The outlet ends may also be provided on opposite sides adjacent to sides 126a, 126b. In one aspect, the outlet end 224c may be characterized as a nozzle. In operation, as the working fluid is delivered to the internal channel 224a via the inlet end 224a, and as the cooling fluid exits the outlet end 224c, the cooling fluid is sprayed or otherwise directed to the coil 124 and adjacent magnets. It should be noted that the shape of the stator core body 126 and the number of stator core bodies 126 disposed in the motor 110 may differ from those shown in the figures without departing from the concepts presented herein. In the disclosed method, improved heat transfer and overall cooling of the motor 110 are achieved when the cooling fluid is in direct contact with the heating wires 124. As previously described, the cooling circuit 224 includes additional paths or branches extending between the inlet end 224b and outlet end 224c of each stator core 122 and the branches 174a, 174b, such as... Figure 11 and Figure 20 As shown schematically, the cooling circuit 224 includes a plurality of sub-circuits associated with each stator core body 126, wherein inlet 224b and outlet 224c are connected together such that pumped working fluid is delivered to each stator core body 126.

[0180] Figure 22 and Figure 23 The stator core body 126 can be manufactured in various ways. For example, a solid stator core body 126, such as a solid metal stator core, can be initially formed and then processed to form internal channels 224a, inlet 224b, and outlet 224c using a drill bit or other tools. Figure 22 and Figure 23 The stator core body 126 can also be formed using additive manufacturing technology.

[0181] Figure 24 and Figure 25 Stator cooling structure

[0182] refer to Figure 24 and 25 The separate stator core body 126 and the wound coil 124 are shown separately to illustrate additional features of the stator assembly 114, which may form part of the cooling circuit 224. Figure 24 and Figure 25 The stator core body 126 can be roughly as follows Figure 6 As shown, the intermediate cooling layer 230 is wound around the sides 126a, 126b, 126c, and 126d of the stator core body 126, such that the intermediate cooling layer 230 is located laterally between and adjacent to the coil 124 and the stator core body 126. Therefore, the intermediate cooling layer 230 is very close to the stator core body 126 and the winding 124 to maximize heat transfer. The intermediate cooling layer 230 can also be referred to as a cooling wrap arrangement. The intermediate cooling layer 230 is adapted to the shape of the stator core / tooth 126 and can be manufactured from multiple parts. In one aspect, and as in... Figure 25 As can be schematically seen, the intermediate cooling layer 230 has a main body 230a with internally embedded channels (e.g., microgrooves) 230b fed by one or more inlets 230c and outlets 230d. Thus, working fluid from the cooling system 170 can be guided through the internal channels 230b to allow heat transfer from the winding 124 to the working fluid. The body 230a may also be provided with a separator 232e, which is part of the main body 230a, and this separator may extend between each individual coil to increase the surface area in direct contact with the coil 124. Additional geometric modifications can be added to the intermediate cooling layer 230 to facilitate optimal design. This intermediate cooling layer 230 can also be used for the purpose of thermal insulation. Ideally, such a material will have high thermal conductivity for optimal thermal performance and high dielectric strength with high voltage capability, such as a thermally conductive, silicone-based material. The intermediate cooling layer 230, including the internal cooling channel 230b, main body 230a, inlet 230c and outlet 230d, and separator 230e, can be manufactured using additive manufacturing processes, but other manufacturing methods are not excluded. It should be noted that the shape of the stator core body 126 and the number of stator cores 122 disposed in the motor 110 may differ from those shown in the figures without departing from the concepts presented herein. As previously mentioned, the cooling circuit 224 includes additional paths or branches extending between the inlet end 224b and outlet end 224c of each stator core intermediate cooling layer 230 and branches 174a, 174b, such as... Figure 11 and Figure 20 As shown schematically, the cooling circuit 224 includes multiple sub-circuits associated with each stator core body 126, wherein inlet 224b and outlet 224c are connected together such that pumped working fluid is delivered to the intermediate cooling layer 230 of each stator core.

[0183] Figure 26 Stator cooling structure

[0184] refer to Figure 18The diagram presents a schematic cross-sectional view of a stator assembly 114 having a stator core 122 and windings 124, the stator assembly also having additional features that can form portions of cooling circuits 222, 226. In one aspect, cooling circuit 222 is formed as a circumferential ring or loop located near the radially inner side of windings 124 of stator core 122, while cooling circuit 226 is also formed as a circumferential ring or loop located near the radially outer side of windings 124 of stator core 122. In the particular example shown, cooling circuits 222, 226 are formed of a thermally conductive material (such as epoxy resin) for maximum heat transfer of cooling fluid from windings 124 to channels 222a, 226a of cooling circuits 222, 226. In one example process, epoxy resin is applied directly to windings 124 to form bodies 222b, 226b, within which windings 124 are embedded and internal channels 222a, 226a are also formed. In this configuration, not only is heat transfer maximized, but the epoxy resin also provides structural rigidity to the motor 110, while minimizing the additional weight due to the cooling system 170. A housing, such as housing 168, could be provided to provide structural rigidity and inlet / outlet ends, among other features, but in this case, housing 168 need not include cooling channels 226a. Furthermore, Figure 26 The cooling channels 222a and 226a shown can be designed to allow flow in any direction. It should also be noted that the motor 110 and the associated cooling system 170 can be configured to include only cooling circuit 222, only cooling circuit 226, or both cooling circuits 222 and 226. For example, Figure 26 The depicted cooling circuit 222 can be associated with, including, Figure 4 and Figure 20 The cooling jacket 167 and the circuit 226 of the channel 167a shown here are used together.

[0185] There are several possible ways to manufacture the cooling channels 222a and 226a within the corresponding bodies 222b and 226b. For example, one method is to utilize a soluble material embedded in the thermally conductive material 222b and 226b, and then dissolve the soluble material to create cavities 222a and 226a. Another alternative would be to embed high thermal conductivity pipes within the thermally conductive material, and then use those pipes as cooling channels 222a and 226a. Other methods of manufacturing such machines / stators are not excluded.

[0186] Figure 27 and Figure 28 Stator cooling structure

[0187] refer to Figure 27 and Figure 28 A schematic cross-sectional view is presented of a stator assembly 114 having a stator core 122 and windings 124, as well as additional features that can form an additional cooling circuit 170, the stator assembly being combined with Figure 4and Figure 20 The disclosed cooling jacket 167 in the configuration shown works together. As previously described, the cooling circuit 226 and the corresponding channel 226a can be provided in the form of cooling jacket 167 and internal channel 167a. Figure 27 and Figure 28 The structure shown is built upon this concept by providing cooling end plates 250, 252 that are adjacent to and in contact with the end faces 134, 135 of the stator core 126, which are respectively incorporated into internal cooling grooves 250a, 252a disposed within the annular main bodies 250b, 252b. Figure 27 As shown, cooling plate 20 may include interconnecting channels, such as channel 250c, to position the internal channels 167a of cooling jacket 167 in fluid communication with the internal cooling slots 250a, 252a. When cooling plates 250, 252 are in direct contact with the stator core body 126, heat transfer is maximized beyond what the cooling jacket 167 alone could achieve. It should be noted that the internal slots 250a, 250b may be interconnected to the internal channels 167a at multiple locations 250c, minimizing the length of any given slot or channel, thereby reducing the associated pressure drop that pump 180 must overcome. Channels 250a, 252a can be arranged in various ways, for example, channels 250a, 252a may be arranged in a serpentine or spiral shape. Although two cooling end plates 250, 252 are shown, cooling system 170 may also include a single cooling end plate 250, 252. In some examples, the cooling end plate is formed of a polymer or plastic material (e.g., a thermoplastic material such as polyetheretherketone (PEEK)).

[0188] Although this disclosure covers certain motor types and geometries, the general cooling concept area is also applicable to other motor topologies and geometries.

[0189] As will be apparent from the foregoing detailed description, modifications and variations may be made to aspects of this disclosure without departing from the spirit or scope thereof. While the best models for implementing many aspects of this teaching have been described in detail, those skilled in the art relating to this teaching will recognize various alternative aspects for practicing this teaching within the scope of the appended claims.

Claims

1. A motor assembly, the motor assembly comprising: a) Motor shaft; b) A rotor assembly comprising two magnetic rotors; c) A stator assembly comprising a plurality of stator cores around which coils are wound, and a thermally conductive material of each stator core is radially located between each stator core and a corresponding coil, the stator assembly defining a ring having radially inner and radially outer sides, wherein the thermally conductive material is wound around a side of a stator core body of each stator core, and the thermally conductive material includes a heat-insulating material; and d) A first cooling circuit for cooling the radially inner side of the stator assembly and a second cooling circuit for cooling the radially outer side of the stator assembly, the first cooling circuit including a plurality of first internal fluid channels around the axis of rotation on the radially inner side of the stator assembly, each first internal fluid channel being defined within the thermal insulation material and located on the radially inner side, the first internal fluid channels being configured to receive cooling fluid, the first cooling channels being spaced apart from each other along the axial dimension of the motor assembly; e) The second cooling circuit includes a plurality of second internal fluid channels, the second cooling circuit including a plurality of second internal fluid channels around the axis of rotation on the radially outer side of the stator assembly, the second cooling channels being spaced apart from each other along the axial dimension of the motor assembly; f) wherein the stator assembly is axially located between the two magnetic rotors; g) An electric motor housing that surrounds the radially outer side of a stator assembly, the electric motor housing including a heat exchanger, wherein both a first cooling circuit and a second cooling circuit are in fluid communication with the heat exchanger.

2. The motor assembly of claim 1, wherein the first internal fluid passage and the second internal fluid passage each include at least one fluid inlet and at least one fluid outlet.

3. A stator assembly for an electric motor, the stator assembly comprising: a) A plurality of stator cores, a coil wound around each stator core, and a thermally conductive material radially located between each stator core and the coil, wherein the thermally conductive material is wound around a side of the stator core body of each stator core, and the thermally conductive material includes a thermally insulating material, the stator assembly defining a ring having a radially inner side and a radially outer side; as well as b) A first cooling circuit for cooling the radially inner side of the stator assembly and a second cooling circuit for cooling the radially outer side of the stator assembly, the first cooling circuit including a plurality of first internal fluid channels around the axis of rotation on the radially inner side of the stator assembly, each first internal fluid channel being defined within the thermally conductive material and located on the radially inner side of the stator assembly, the first internal fluid channels being configured to receive cooling fluid, the first cooling channels being spaced apart from each other along the axial dimension of the motor assembly; c) The second cooling circuit includes a plurality of second internal fluid channels, the second cooling circuit including a plurality of second internal fluid channels on the radially outer side of the stator assembly around the axis of rotation, the second cooling channels being spaced apart from each other along the axial dimension of the motor assembly; d) A motor housing surrounding the radially outer side of a stator assembly, the motor housing including a heat exchanger, wherein both a first cooling circuit and a second cooling circuit are in fluid communication with the heat exchanger.

4. The stator assembly of claim 3, wherein the first internal fluid passage and the second internal fluid passage each include at least one fluid inlet and at least one fluid outlet.

5. A method for cooling a stator assembly of a motor assembly according to claim 1 or 2, the method comprising: a) Cooling fluid is delivered through a first cooling circuit and a second cooling circuit to multiple stator cores, with coils wound around each stator core; as well as b) The cooling fluid is directed through one or more internal channels of a thermally conductive material located between and adjacent to at least one stator core and the coil; The thermally conductive material is wound around a side of the stator core body of each of the plurality of stator cores, and the thermally conductive material includes a thermally insulating material. The first cooling circuit includes a plurality of first internal fluid channels, and the second cooling circuit includes a plurality of second internal fluid channels. The first internal fluid channels are defined within the thermally conductive material on the radially inner side of the stator assembly, and the second internal fluid channels are defined within the thermally conductive material on the radially outer side of the stator assembly. Both the first cooling circuit and the second cooling circuit are in fluid communication with the heat exchanger.

6. The method of claim 5, wherein the delivery step is performed using a pump.

7. The method of claim 5 or 6, wherein the delivery step is performed using a pump driven by the motor.

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