Electric fan liquid cooling

Abstract

A system (52; 152; 252) includes an electric motor assembly (172; 272), an electronics assembly (170; 270), inlet and outlet ports (180A and 180B; 280-1 to 280-4), and an internal liquid cooling path (CI; CI'; CI") between the inlet and outlet ports. The electric motor assembly includes a stator (172-2; 272-2) with a winding, a rotor (172-3; 272-3), a motor housing (172-1; 272-1), and a jacket passage (186; 286) located in the motor housing and positioned radially outward from the winding. The stator and the rotor are each positioned at least partially within the motor housing. The electronics assembly includes inverter circuitry (170-3I; 270-3I), a housing base, and a cavity (182; 282) located at least partially in the housing base. The inverter circuitry is located at least partially within the housing base and adjacent to the cavity. The internal liquid cooling path passes through the jacket passage and the cavity.

Description

ELECTRIC FAN LIQUID COOLINGCROSS-REFERENCE TO RELATED APPLICATION(S)

[0001] The present application is based on and claims the benefit of and priority to U.S. provisional patent application Serial No. 63 / 670,328, filed July 12, 2024.FIELD

[0002] The present invention generally relates to liquid cooling for electric systems, including liquid cooling for high voltage electric fan systems, and encompasses both an apparatus and method for liquid cooling the same. Additionally, the present invention relates to an electric fan system and method of making and using the same.BACKGROUND

[0003] Initiatives are underway to limit greenhouse gas emissions and other types of emissions, including CO2 and NOXemissions. In pursuit of those objectives, alternative powertrains are being developed to replace an internal combustion engine. These include powertrain applications for vehicles like heavy-duty trucks and off-highway vehicles such as construction and mining equipment (for example, excavators, graders, loaders, and mining vehicles) with relatively high torque capacities. A need exists to provide cooling for a variety of systems on these types of equipment and vehicles. Electric powertrains on such vehicles typically consist of motors, electronic drives (often referred to as inverters), and mechanical transmissions. These devices are powered by an energy source such as a battery or fuel cell. Those energy sources are typically carried on the vehicle along with the electric powertrain. Hybrid vehicles that include both an internal combustion engine and an alternative drive are also possible. All these types of vehicles can still require significant cooling to protect their on-board systems from thermal damage.

[0004] Many such electrically-powered drivetrains are intended to operate at high voltages in order to constrain the size of electrical conductors, such as in the range of (nominally) approximately 400 to 1200 volts direct current (VDC), or in the range of approximately 450 to 850 VDC or approximately 800 to 1200 VDC or approximately 1000 to 1200 VDC, as other examples.On-board vehicle cooling systems will generally be powered by the same on-board energy sources as the electric powertrain, and at least some cooling system components will therefore operate at the same high voltages.

[0005] Electric fan and inverter units (also called eFans) can be used to provide cooling airflows for zero emission vehicles (ZEVs) and similar off-highway equipment as well as in industrial applications. Such eFans can operate at relatively high voltages. However, operation of the fan and associated power electronics can generate a significant amount of heat, which must be handled in such a way as to provide for efficient operation without significant risk of damage or degradation of the eFan components (and potentially also nearby objects). Liquid cooling can be used to thermally regulate such an eFan system. An example of a high voltage electric fan system with liquid cooling is disclosed in commonly- as signed PCT International Patent App. Publication No. WO 2023 / 178301 Al, for example.

[0006] It is desired to provide improved liquid cooling for an electrically-powered system such as an electric fan system that allows for improved thermal management. Also, it is desired to provide an electric fan system with improved manufacturability.SUMMARY

[0007] In one aspect, a system according to the present invention can include an electric motor assembly, an electronics assembly, an inlet port, an outlet port, and an internal liquid cooling path extending between the inlet port and the outlet port. The electric motor assembly can include a stator including a winding, a rotor rotatable about an axis and positioned adjacent to the stator, a motor housing, with the stator and the rotor each positioned at least partially within the motor housing, and a jacket passage located in the motor housing and positioned radially outward from the winding. The electronics assembly can include inverter circuitry electrically connected to the winding to selectively power the electric motor assembly, a housing base, with the inverter circuitry located at least partially within the housing base, and a cavity located at least partially in the housing base, such that the inverter circuitry is located adjacent to the cavity. The internal liquid cooling path can be configured to pass through the jacket passage and the cavity.

[0008] In another aspect, a method of cooling an electric motor system can include operating electronic switching circuity, which generates waste heat, absorbing at least a portion of the waste heat in a liquid coolant passing along an internal liquid cooling path through a cavity locatedadjacent to the electronic switching circuitry, selectively powering an electric motor to generate an output torque as a function of operating the electronic switching circuitry, which further generates waste heat, absorbing at least a portion of the waste heat in the liquid coolant passing along the internal liquid cooling path through a jacket passage located adjacent to and radially outward from a winding of the electric motor, and passing the liquid coolant through an outlet port at a terminus of the internal liquid cooling path after absorbing the waste heat.

[0009] In yet another aspect, a system can include an electric motor assembly, an electronics assembly, and an internal liquid cooling path. The electric motor assembly can include a stator, a rotor rotatable about an axis, a motor housing, with the stator and the rotor each positioned at least partially within the motor housing, and a jacket passage located in the motor housing and extending circumferentially around at least a portion of the stator. The electronics assembly can include inverter circuitry electrically connected to the electric motor assembly, a housing base and a cover forming an enclosure with an internal cavity, with the inverter circuitry located at least partially within the internal cavity of the enclosure, and a liquid cooling cavity in the housing base, the liquid cooling cavity arranged to be axially offset from the jacket passage. The internal liquid cooling path can pass proximate to the inverter circuitry and at least one of the stator and / or the rotor to absorb waste heat, such that a first volume of a liquid coolant passing through internal liquid cooling path absorbs the waste heat from both the inverter circuitry and from at least one of the stator and / or the rotor.

[0010] In yet another aspect, an electric motor system includes an inlet port at an inlet of an internal liquid cooling path of the electric motor system, electronic switching circuity, a cavity located adjacent to the electronic switching circuitry, an electric motor with a winding operably powered by the electronic switching circuitry, a jacket passage located adjacent to and radially outward from the winding of the electric motor, and an outlet port at a terminus of the internal liquid cooling path. The internal liquid cooling path passes through the cavity and the jacket passage.

[0011] The present summary is provided only by way of example, and not limitation. Other aspects of the present invention will be appreciated in view of the entirety of the present disclosure, including the entire text, claims, and accompanying figures.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 is a schematic block diagram of an embodiment of a vehicle with a high voltage cooling fan system.

[0013] FIG. 2 is a perspective view of an embodiment of a portion of a high voltage cooling fan system.

[0014] FIG. 3 is a sectional view of the high voltage cooling system of FIG. 2, taken along line 3-3.

[0015] FIG. 4 is a perspective view of an internal liquid cooling path of the high voltage cooling system of FIGS. 2 and 3, shown in isolation.

[0016] FIG. 5 is a front elevation view of an inverter enclosure of the high voltage cooling system of FIGS. 2 to 4, shown in isolation.

[0017] FIG. 6 is a top plan view of the inverter enclosure of the high voltage cooling system of FIGS. 2 to 5, shown in isolation.

[0018] FIG. 7 is a top plan view of an internal portion of the high voltage cooling system of FIGS. 6.

[0019] FIG. 8A is a sectional view of an alternate embodiment of the high voltage cooling system.

[0020] FIG. 8B is a perspective view of a portion of an inverter enclosure of the high voltage cooling system of FIG. 8A.

[0021] FIG. 9 is a perspective view of another embodiment of a portion of a high voltage cooling fan system.

[0022] FIGS. 10 and 11 are sectional views of the high voltage cooling system of FIG. 9, taken along lines 10-10 and 11-11, respectively.

[0023] FIG. 12A is a perspective views of a high voltage power module cooling plate unit, shown in isolation.

[0024] FIG. 12B is a perspective view of another embodiment of a high voltage power module cooling plate unit, shown in isolation.

[0025] FIG. 13 is a perspective view of simulated liquid coolant flow through an embodiment of an internal liquid cooling path of the high voltage cooling system of FIGS. 9 to 12A.

[0026] FIG. 14 is a perspective view of simulated liquid coolant flow through another embodiment of an internal liquid cooling path of the high voltage cooling system.

[0027] While the above-identified figures set forth one or more embodiments of the present invention, other embodiments are also contemplated as noted in the discussion, hi all cases, this disclosure presents the invention by way of representation and not limitation. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art, which fall within the scope and spirit of the principles of the invention. The figures may not be drawn to scale, and applications and embodiments of the present invention may include features, steps, and / or components not specifically shown in the drawings.DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0028] In general, one aspect of the present invention provides a cooling system and method that is suitable for use with electrically-powered devices that include both an electric motor and associated control or driver electronics, such as an inverter, that generate significant waste heat and benefit from regulation of operational temperatures through liquid cooling. The cooling system can help cool multiple different locations (e.g., both electric motor winding(s) and inverter components spaced from the motor winding(s)) using an integrated liquid coolant flowpath and / or a single liquid coolant source. Such a cooling system may be particularly beneficial for high voltage electric cooling fan systems, including those usable in either on- and off-highway vehicles or in non- vehicular industrial applications, which can operate in the range of (nominally) approximately 400 to 1200 volts direct current (VDC), or more, approximately 450 to 850 VDC, or approximately 800 to 1200 VDC, or approximately 1000 to 1200 VDC, for example. The cooling system and method can involve a complex three-dimensional cooling path that can tailor cooling to hotter locations without significant stagnant flows, dead zones, or the like, and without the need for actively-controlled valves or special pumps (apart from a system-wide circulating pump). Increased surface areas, flow division or blockage, and / or turbulence-generators can also be utilized to tailor dynamic cooling performance, as explained herein. Some embodiments can also allow for single-inlet and single-outlet connections to a larger liquid cooling circuit that rejects waste heat from a liquid coolant, thereby allowing for relatively simple plumbing connections. At least some embodiments of the invention can help provide a relatively compact fan unit, particularly in an axial direction. Numerous other features and benefits will be recognized by persons of ordinary skill in the art in view of the entirety of the present disclosure, including the accompanying drawings.

[0029] FIG. 1 is a schematic block diagram of an embodiment of a vehicle 50 with a high voltage electric cooling fan system 52. As shown in the embodiment of FIG. 1, the vehicle 50 has various on-board systems including electrically-powered devices 53 (such as a traction motor, other types of electric motors, an electric heater, an electric pump, control / power electronics, etc.), a high voltage electrical power supply 55 (e.g., batteries and / or fuel cells), a heat exchanger assembly 57, and the high voltage electric cooling fan system 52 (shown with an optional associated circulating pump 52P). Various additional on-board systems, including a compressor 59C, an evaporator 59E, a pump 61, and an optional valve 63, are illustrated in FIG. 1 as examples of components that could be used as part of separate on-board cooling systems used in addition to the high voltage electric cooling fan system 52. Moreover, an example electronic control unit (ECU) 65 with processing and control functionality is shown (e.g., an on-board vehicle computer). Although not depicted separately in FIG. 1, the power supply 55 can include an inductive charging subsystem in some embodiments where the power supply 55 includes batteries. Certain electrical connections between components for power supply and / or communications signals are shown in dashed lines in FIG 1; however, for simplicity, not all electrical connections are specifically shown in FIG. 1 and additional electrical connections can be provided as desired and as would be understood by persons of ordinary skill in the art.

[0030] As shown in FIG. 1, the high voltage electric cooling fan system 52 can be positioned near the heat exchanger assembly 57 in order to move cooling air through the heat exchanger assembly 57. The high voltage electric cooling fan system 52 can include one or more motor(s), one or more fan(s), and one or more electronic control modules (often referred to simply as an inverter). In some embodiments, the high voltage electric cooling fan system 52 can be the same or similar to a configuration disclosed in commonly-assigned PCT International Patent Application Pub. No. WO 2023 / 178301 Al, for example. However, the present invention can also be used with other types or configurations of electrically powered systems, for vehicular and non-vehicular industrial applications.

[0031] In some embodiments, the heat exchanger assembly 57 can include multiple discrete liquid / air heat exchangers arranged as an axial stack and / or in a side-by-side array. FIG. 1 illustrates an embodiment with an axially stacked heat exchanger assembly 57 that includes first and second liquid-to-air heat exchangers (or radiators) 57A and 57B, and a condenser 57C. In embodiments where the high voltage electric cooling fan system 52 includes a liquid coolingcircuit C, that liquid cooling circuit C can be tied to at least one liquid / air heat exchanger (radiator) 57B in the heat exchanger assembly 57. The condenser 57C can operate with the compressor 59C and the evaporator 59E as part of a chiller or air conditioning system, and the heat exchanger 57A can remove waste heat from liquid coolant used to cool the vehicle’s traction motor (as one of the electrically-powered devices 53, but not shown more specifically in FIG. 1), for example. In various embodiments, the liquid cooling circuit C can operate at the same or a similar temperature range as a liquid cooling circuit associated with the heat exchanger 57A or alternatively at a different thermal operating range.

[0032] FIGS . 2 to 7 illustrate aspects of an embodiment of a portion of a high voltage cooling fan system 152 that includes an electronics assembly 170 and an electric motor assembly 172. The high voltage cooling fan system 152 can be utilized like the high voltage electric cooling fan system 52 in the vehicle 50, or in other applications. In the illustrated embodiment, the electronics assembly 170 is located adjacent to the electric motor assembly 172, with the electronics assembly 170 attached to the electric motor assembly 172 to form a combined unit. A fan (not shown) can be operatively attached to the electric motor assembly 172, to rotate about an axis A. A liquid cooling circuit C is also shown schematically, a portion of which passes through or adjacent to both the electronics assembly 170 and the electric motor assembly 172. The liquid cooling circuit C can extend through a heat exchanger (for example, the heat exchanger 57B) and can further pass through suitable hoses or the like (not shown). In that way, a liquid coolant present in the liquid cooling circuit C can accept thermal energy from the electronics assembly 170 and / or the electric motor assembly 172 to carry away waste heat and regulate operating temperatures of such components. One or more additional electric motor assemblies or other heat-generating components can optionally be connected to the liquid cooling circuit C as well, in some embodiments.

[0033] In the illustrated embodiment, the electronics assembly 170 includes a housing base 170-1 and a cover 170-2 that provide an enclosure for electronics circuitry 170-3 (shown only schematically in FIG. 3), which is positioned in an internal cavity of the electronics assembly 170. The housing base 170-1 and the cover 170-2 can each be made of a metallic material, such as aluminum. The electronics circuitry 170-3 can include high voltage inverter circuitry 170-31, filter circuitry, and optionally also low voltage communications circuitry, and can be implemented on one or more circuit boards. For example, the inverter circuitry 170-31 of the electronics circuitry170-3 can include power electronics with high-speed electronic switching devices known as insulated-gate bipolar transistors (IGBTs) or Silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs). Inverter circuitry switches high voltage current at a very high frequency. Because of the rapid switching, the inverter circuitry 170-31 has energy losses in the form of heat. As such, the inverter circuitry 170-31 is particularly prone to generating significant amounts of waste heat. A cold plate and / or thermal paste or a thermal pad can be positioned adjacent to the electronics circuitry 170-3, in between the electronics circuitry 170-3 (and the inverter circuitry 170-31) and a wall 180-1W (e.g., a generally radially-extending wall) of the housing base 170-1, to facilitate thermal energy transfer from the inverter circuitry 170-31 to liquid coolant present in the liquid cooling circuit C, as will be explained further. Low voltage portions of the electronics circuitry 170-3 tend to generate significantly less waste heat. Therefore, the inverter circuitry 170-31 can be positioned in close proximity to the liquid cooling circuit C to facilitate removal of waste heat, while low voltage circuitry and / or high voltage circuitry less prone to generating waste heat can be located relatively further away from the liquid cooling circuit C, in some embodiments.

[0034] The electric motor assembly 172 of the illustrated embodiment includes a motor housing 172-1, a stator 172-2, a rotor 172-3, an output member 172-4, bearings 172-5, and a mechanical fastener 172-6. The electric motor assembly 172 can have a permanent magnet synchronous motor configuration, such as a three-phase brushless DC (BLDC) design, with the stator 172-2 having a stator winding (shown in a simplified schematic manner in FIG. 3) and the rotor 172-3 having permanent magnets 172-3M. In the illustrated embodiment, the permanent magnets 172-3M are carried by a rotor wheel (or disc or the like) 172-3W that is engaged with the output member 172-4 to rotate together at all times. The engagement of the rotor wheel 172-3W and the output member 172-4 can be made using a mechanical fastener 172-6 (for example, a threaded bolt or screw) or alternatively with a swaged connection. The stator 172-2 and the rotor 172-3 can be mostly or entirely positioned within an interior cavity of the motor housing 172-1, and a rear face of the motor housing can be closed (in a sealed manner) by the housing base 170- 1 of the electronics assembly 170 in some embodiments. The output member 172-4 can be configured as a fan mount, such as with a generally axially-extending shaft portion and a generally radially extending attachment portion that can have or carry a fan pilot and / or fan attachment studs to permit attachment of a fan. The output member 172-4 extends outside the motor housing 172-1 and axially traverses a portion of the motor housing 172- 1. The output member 172-4 is rotatable about the axis A. In the illustrated embodiment, the bearings 172-5 are a single set of double-row bearings with common inner and outer races, respectively (but could instead be two closely adjacent single-row bearing sets in an alternate embodiment, for example). The bearings 172-5 rotatably support the output member 172-4 (and in turn the rotor 172-3) on the motor housing 172- 1. Such an arrangement of the bearings 172-5 in a middle portion of the rotatable components helps ease manufacturing and assembly and also helps permit an axially shorter motor assembly 172 (and overall high voltage cooling fan system 152) as compared to an arrangement with separate bearing sets at opposite ends of a rotor / output shaft. The motor housing 172-1 can be made of a metallic material such as aluminum. In some embodiments, the motor housing 172-1 can be attached to the housing base 170-1. Conductive grease can be used with the bearings 172- 5 to help reduce eddy currents.

[0035] An embodiment of an internal liquid cooling path Ci, which forms a portion of the liquid cooling circuit C that passes through the high voltage cooling fan system 152, is illustrated in FIGS. 3-5. As shown, the internal liquid cooling path Ci extends from an inlet port 180A in the housing base 170-1 of the electronics assembly 170 to a cavity (or liquid cooling cavity) 182 with pin fins 184 located proximate to the electronics circuitry 170-3 then to a jacket passage 186 in the motor housing 172-1 and then to an outlet port 180B in the housing base 170-1 of the electronics assembly 170 (at a terminus of the internal liquid cooling path Ci). The internal liquid cooling path Ci can have a complex three-dimensional shape. As shown in FIG. 5, the internal liquid cooling path Ci can pass from point Ci-1 at the inlet port 180A to point Ci-2 at one part of the cavity 182 to point Ci-3 at a different part (e.g., a generally opposite side) of the cavity 182 to point Ci-4 at an inlet of the jacket passage 186 to point Ci-5 at a circumferentially middle part of the jacket passage 186 to point Ci-6 at an outlet from the jacket passage 186 to point Ci-7 at the outlet port 180B. Moreover, as shown in FIG. 4, the internal liquid cooling path Ci can extend radially inward from the inlet port 180A to the cavity 182 (and optionally also traverse an axial distance).

[0036] The cavity 182 can be formed in the wall 170-1W of the housing base 170-1 (e.g., as a depression therein), which can define at least a portion of the boundary of the cavity 182, and a face of the cavity 182 can be closed (and sealed) by a cover 188. For example, the cavity 182 can have an open face (covered by the cover 188) that faces toward the electric motor assembly 172. In the illustrated embodiment, the cavity 182 has generally flat front and real' sides, and partiallyflat and partially curved perimeter in between the front and rear sides, although other shapes are possible in further embodiments. The cavity 182 can be shaped, sized, and positioned to extend along all or most of the inverter circuitry 170-31 in the radial circumferential direction (and optionally also in the circumferential direction) and in relatively close proximity in the axial direction. Further, in some embodiments, the cavity 182 can be arranged radially inward from the stator 172-2. As shown the cavity has an inlet 182A and an outlet 182B at generally opposite sides. The inlet 182A can be located proximate the inlet port 180A in the internal liquid cooling path Ci.

[0037] The pin fins 184 are shown in the illustrated embodiment as substantially cylindrical posts that extend axially from the wall 170- 1W at the side of the cavity 182 that faces the electronics circuitry 170-3. The pin fins 184 can extend across most but not an entire axial dimension of the cavity 182, such that the pin fins 184 extend close to but do not touch the cover 188. At least some of the pin fins 184 are positioned in between the cavity inlet and outlet 182A and 182B as an obstacle or interruption that effectively increases a length of the shortest fluid path through the cavity 182 between the inlet and outlet 182A and 182B. The pin fins 184 can be arranged in staggered rows. In further embodiments, the pin fins 184 can be canted, can have different shapes (e.g., chevron, frusto-conical, conical, pyramidal, frustum, rectangular box, obround, arced / curved, blade- or airfoil-like, and / or other suitable shapes), etc. The number of pin fins 184 can also vary as desired. The pin fins 184 help to increase surface area for conductive heat transfer to liquid coolant present in the cavity 182, and, moreover, can generate turbulence that can help promote convective heat transfer in liquid coolant present in the cavity 182.

[0038] The jacket passage 186 can have an annular shape and can extend generally circumferentially around the stator 172-2 and its winding(s) in close proximity to the stator 172-2 to absorb heat generated in the stator 172-2. In that way, liquid coolant in the jacket passage 186 provides a cooling jacket to help cool the electric motor assembly 172. In the illustrated embodiment, the jacket passage 186 is partially bounded by material of the motor housing 172-1 of the electric motor assembly 172 and partially by the wall 170- 1W of the housing base 170-1 of the electronics assembly 170, such that the internal liquid cooling path Ci is exposed to the housing base 170-1 and liquid coolant present therein is in contact with the housing base 170-1 along essentially the entire internal liquid cooling path CL hi an alternate embodiment the jacket passage 186 could be bounded essentially entirely by the motor housing 172-1 instead, and / or the internalliquid cooling path Ci could be spaced from the housing base 170-1 along part of the internal liquid cooling path CL The jacket passage 186 has an inlet 186A located proximate to the outlet 184B of the cavity 182 in the internal liquid cooling path Ci and an outlet 186B located at a circumferentially spaced location. In the illustrated embodiment, the jacket passage 186 is unbranched, and is positioned entirely radially outside the winding(s) of the stator 172-2, that is, the jacket passage 186 is located radially outward from the stator 172-2 in close proximity to winding(s) and other structures of the stator 172-2, although other configurations are possible in further embodiments. The jacket passage 186 can be axially and / or radially offset from the cavity 182, and the internal liquid cooling path Ci can traverse an axial distance and / or a radial distance in between the outlet 182B and the inlet 186A. In the illustrated embodiment, the jacket passage 186 extends circumferentially almost but less than 360°, such that a barrier 172- IB is present between opposite circumferential ends of the jacket passage 186. hi the illustrated embodiment, the barrier 172- IB completely circumferentially obstructs fluid flow, although in alternate embodiments a partial barrier (or divider) could be utilized instead that permits some liquid coolant to flow circumferentially 360° or more within the jacket passage 186. Moreover, in some embodiments, the inlet 186A and the outlet 186B are both located proximate the barrier 172- IB on circumferentially opposite sides of the barrier 172- IB. The outlet 186B can be located proximate to the outlet port 180B in the internal liquid cooling path CL The internal liquid cooling path Ci can optionally traverse an axial distance in between the outlet 186B and the outlet port 180B.

[0039] As shown in the illustrated embodiment (see FIG. 4), the barrier 172- IB and the cavity 182 are circumferentially arranged such that the internal liquid cooling path Ci extends circumferentially more than 360° between the inlet and outlet ports 180A and 180B. For example, in the illustrated embodiment, the barrier 172-1B and the inlet 186A are both located outside of a smallest circumferential arc 0 between the inlet and outlet ports 180A and 180B. Moreover, in some embodiments, the cavity 182, or at least a distance between the inlet 182A and the outlet 182B thereof, provides a portion of the internal liquid cooling path Ci that extends over a greater circumferential distance than does the barrier 172- IB, and the portion of the internal liquid cooling path Ci that extends through the cavity 182 can at least partially overlap with one or more portions of the jacket passage 186. Furthermore, in some embodiments, the internal liquid cooling path Ci can extend in the circumferential direction less than 360° through the electric motor assembly 172,-Ilalone, and also less than 360° through the electronics assembly 170, alone, but with a combined or total circumferential path through the entire high voltage cooling fan system 152 that extends circumferentially more than 360°. Furthermore, in some embodiments, the internal liquid cooling path Ci extends in one generally circumferential direction (e.g., clockwise) through both the cavity 182 and the jacket passage 186.

[0040] The internal liquid cooling path Ci, and portions thereof, can be made through casting and / or machining (such as drilling and / or milling), as well as through mechanical engagements between adjoining parts and the provision of suitable seals (for example, O-ring seals) at interfaces. Portions of the internal liquid cooling path Ci like the cavity 182 and the jacket passage 186 can, for instance, be cast into the housing base 170-1 and the motor housing 172-1 and optionally finish machined to follow, or instead be fully machined. The pin fins 184 can be integrally and monolithically made with adjoining structures, such as a portion of the housing base 170-1 along the cavity 182, or can alternatively be mechanically attached to the housing body in a suitable manner. Connecting passages of the internal liquid cooling path Ci between the cavity 182 and the jacket passage 186 can, for instance, be made with a number of drill operations in various directions, and certain portions of drilled passages plugged or otherwise sealed in order to define a desired shape of the internal liquid cooling path Ci with suitable fluidic connections between various portions of the internal liquid cooling path CL

[0041] During operation of the high voltage cooling fan system 152, electrical power is supplied to the electronics assembly 170, including to the electronics circuitry 170-3 and the inverter circuitry 170-31. Moreover, the electronics circuitry 170-3, and the inverter circuitry 170- 31 specifically, selectively power the electric motor assembly 172, including the winding(s) of the stator 172-2, in order to selectively generate torque and rotate the rotor 172-3 and the output member 172-4 as well as any attached cooling fan or other attached device that accepts torque output. In that sense, the electronics circuitry 170-3, including the inverter circuitry 170-31, is electrically connected to the electric motor assembly 172 (e.g., to the winding(s) of the stator 172- 2). Heat is generated by the electronics circuitry 170-3, particularly the inverter circuitry 170-31, and by the electric motor assembly 172, particularly the winding(s) of the stator 172-2, when electrically powered. Cooling is provided to the high voltage cooling fan system 152 by liquid coolant that flows along the liquid cooling circuit C and through the internal liquid cooling path CL Flow of the liquid coolant through the liquid cooling circuit C can be generated by thecirculating pump 52P, for example, in some embodiments. The internal liquid cooling path Ci can flow through each of the electronics assembly 170 and the electric motor assembly 172, and liquid coolant present in the internal liquid cooling path Ci can absorb thermal energy (that is, heat) to regulate temperatures of or within the high voltage cooling fan system 152. In the illustrated embodiment, the internal liquid cooling path Ci flows serially through the cavity 182 followed by the jacket passage 186, which allows a first volume (or a single common volume) of the liquid coolant to absorb heat from both the electric motor assembly 172 (e.g., from the stator 172-2 and / or the rotor 172-3) and the electronics assembly 170 (e.g., from the inverter circuitry 170-31). Such an arrangement prioritizes cooling to the electronics assembly 170 while also providing suitable cooling to the electric motor assembly 172. More particularly, in the illustrated embodiment, the internal liquid cooling path Ci flows from point Ci-1 at the inlet port 180A to point Ci-2 at one part of the cavity 182 to point Ci-3 at a generally circumferentially opposite side of the cavity 182 to point Ci-4 at an inlet of the jacket passage 186 to point Ci-5 at a circumferentially middle part of the jacket passage 186 to point Ci-6 at an outlet from the jacket passage 186 to point Ci-7 at the inlet port 180B. In this way, the liquid coolant flowing through the entire internal liquid cooling path Ci can travel more than 360° around the high voltage cooling fan system 152. In alternate embodiments, parallel or hybrid series / parallel flowpaths through the cavity 182 followed by the jacket passage 186 are possible. Moreover, the liquid cooling circuit C can optionally also flow through one or more additional discrete high voltage cooling fan systems and / or other heatgenerating components, and can do so in series, parallel, or a hybrid series / parallel flow relationship with the internal liquid cooling path Ci of the high voltage cooling fan system 152.

[0042] FIGS. 5 and 6 show internal portions of the high voltage cooling fan system 152. As illustrated in FIGS. 5 and 6, free ends 184F of the pins fins 184 are spaced from the cover 188 inside the cavity 182 by gaps G, and the gaps G can be arranged axially. In the illustrated embodiment, each of the free ends 184F of the pin fins 184 is spaced from cover 188 by the same or substantially the same distance, with the gaps G having a uniform size, although in alternative embodiments the size of the gaps G at different ones of the free ends 184F can vary. In one example embodiment (see FIG. 7), the pin fins 184 are cylindrical with a diameter of 2 mm and are configured in a regular 3 mm x 3 mm diagonal pattern in an X-Y Cartesian coordinate plane, that is, with approximately 4.24 mm on-center minimum spacing D, and with the gaps G all being 2 mm. It is believed that the gaps G aid in cooling by allowing the liquid coolant present in theintemal liquid cooling path Ci to better maintain velocity and to fully encapsulate the free ends 184F of the pin fins 184. Moreover, the staggered arrangement and relative size and spacing aspects of the configuration of the pin fins 184 shown in FIGS. 5-7 can help promote suitable cooling characteristics for certain applications.

[0043] FIGS. 8 A and 8B illustrate an alternate embodiment of a portion of the high voltage cooling fan system 152. More particularly, FIG. 8 A and 8B show an alternate configuration of a cavity 182’. As shown in the illustrated embodiment, the cavity 182’ includes a main portion 182’- 1, an inlet portion 182’ -2, and an outlet portion 182’ -3. In the illustrated embodiment, the main portion 182’ - 1 has a substantially rectangular shape, although other shapes are possible in further embodiments. The main portion 182’- 1 can contain a plurality of the pin fins 184, which, in some embodiments, can be configured in the same manner as described above with respect to another embodiment. For example, the main portion 182’ -1 can be aligned or substantially aligned with the inverter circuitry 170-31 and can have a similar or identical size and perimeter shape. The inlet portion 182’-2 is fluidically connected to the inlet 182A and the main portion 182’- 1 and can (at least partially) have a diverging shape, such that the inlet portion 182’-2 is larger at the main portion 182’-l than at the inlet 182A. In the illustrated embodiment, the inlet portion 182’-2 includes an upstream channel part that directly fluidically connects to the inlet 182A and is relatively narrow with a substantially constant size plus a downstream diverging part that directly fluidically connects to the main portion 182’-1. The upstream channel part of the inlet portion 182’ -2 can be canted, angled, curved, or otherwise include differently-oriented segments between the inlet 182A and the main portion 182’-! in some embodiments. The outlet portion 182’-3 is fluidically connected to the main portion 182’-1 and the outlet 182B and can (at least partially) have a converging shape, such that the inlet portion 182’ -2 is smaller at the outlet 182B than at the main portion 182’ - 1. In the illustrated embodiment, the outlet portion 182’ -3 includes an upstream converging part that directly fluidically connects to the main portion 182’-1 plus a downstream channel pail that is relatively narrow with a substantially constant size that directly fluidically connects to the outlet 182B. The downstream channel part of the outlet portion 182’ -3 can be canted, angled, curved, or otherwise include differently-oriented segments between the main portion 182’ - 1 and the in some embodiments. In the illustrated embodiment, the channel pail of the outlet portion 182’-3 includes multiple segments that are angled relative to each other.

[0044] At least one diverter 185 can be provided in the cavity 182’. In the illustrated embodiment, a diverter 185 is positioned in the diverging part of the inlet portion 182’ -2 adjacent to the main portion 182’- 1. In alternate embodiments, some or all of the diverter(s) 185) can be positioned in the main portion 182’-1 instead. The diverter 185 can have a wedge shape in some embodiments. The liquid coolant flowing through the cavity 182’ can be dispersed by the diverter(s) 185 to different parts of the main portion 182’- 1 and / or at or to different ones of the pin fin 184, to facilitate wider, more even, and / or more turbulent fluid flow to help absorb thermal energy. For instance, flows of the liquid coolant can be distributed in multiple different directions using the diverter(s) 185. The diverter(s) can be located upstream from the pin fins 184 in the internal liquid cooling path Ci, such that liquid coolant flows can be diverted in different directions prior to encountering the pin fins 184.

[0045] FIGS. 9 to 14 illustrate aspects of another embodiment of a portion of a high voltage cooling fan system 252. In general, the configuration and operation of the high voltage cooling fan system 252 is similar to that of the high voltage cooling fan system 152. Accordingly, similar reference numbers as used with respect to the high voltage cooling fan system 152 are utilized increased by one hundred for the high voltage cooling fan system 252, with notable differences explained below. A fan F is explicitly shown with the high voltage cooling fan system 252 in FIGS. 9-11, which can rotate about the axis A.

[0046] The motor assembly 272 in the illustrated embodiment includes two single-row bearings 272-5A and 272-5B that are spaced apart at generally axially opposite ends of a shaft portion of the rotor wheel 272-3 W (of the rotor 272-3). The fan F is secured to the output member 272-4, which in turn is engaged to the rotor wheel 272-3W, such that the fan F is rotatable when the motor assembly 272 produces a torque output.

[0047] The high voltage cooling fan system 252 of the illustrated embodiment has four liquid cooling ports 280-1, 280-2, 280-3, and 280-4, with the ports 280-1 and 280-2 located in or along the motor housing 272-1 and with the ports 280-3 and 280-4 located in or along the housing base 270-1. As illustrated, the ports 280-1 and 280-2 are located at the jacket passage 286 while the ports 280-3 and 280-4 are located at the cavity 282. The barrier 272-1B can be located circumferentially in between the ports 280-1 and 280-2. The jacket passage 286 of the illustrated embodiment is annular in shape and is tapered in the axial direction.

[0048] The cavity (or liquid cooling cavity) 282 can be defined in the wall 270- 1W of the housing base 270-1. As shown in the illustrated embodiment, the cavity 282 has an open face (covered by the cover 288) that faces away from the motor assembly 272 and toward the electronics circuitry 270-3 and the inverter circuitry 270-31. The pin fins 284 extend from the cover 288 toward the wall 270- 1W in the illustrated embodiment, as part of a high voltage power module cooling plate unit, with axial gaps between the wall 270- 1W and the pin fins 284. In some embodiments, the pin fins 284 can have configurations such as with arrangements, sizes, and relative spacings that are the same or similar to those described above with respect to FIGS. 6 and 7, or can have other configurations in further embodiments. Additionally, the cavity 282 and the jacket passage 286 are fluidically connected via bores 282-1 and 282-2. In the illustrated embodiment, the two bores 282-1 and 282-2 are arranged generally axially and are located at circumferentially opposite ends of the jacket passage 286 proximate opposite sides of the barrier 272- IB. Moreover, in the illustrated embodiment, the bore 282-1 is substantially circumferentially aligned with both of the ports 280-1 and 280-3 while the bore 282-2 is substantially circumferentially aligned with both of the ports 280-2 and 280-4, although other arrangements are possible in further embodiments.

[0049] A divider 290 can be provided in the cavity 282. In the illustrated embodiment of FIGS. 9 to 12A, the divider 290 is a wall or fin that can limit or block liquid flow (e.g., to block fluid flow in a generally circumferential direction) that extends from the cover 288 toward the motor assembly 272 and the wall 170- 1W, with a small axial gap between the wall 170- 1W and the divider 290. The gap between the wall 170- 1W and the divider 290 can be smaller than the gaps between the wall 170- 1W and the pin fins 284, in some embodiments, such that the pin fins 284 extend more than halfway, more than 66%, or more than 75% across the cavity 282 in the axial direction while the divider 290 extends almost entirely across the cavity 282 in the axial direction. Further, in some embodiments, the divider 290 can be substantially planar, although curved or otherwise non-planar configurations are possible in alternate embodiments. Moreover, pin-fins or partial pin-fins can be integrated with the divider 290, which can extend from sides of the divider 290 and function like the pin fins 284, in some embodiments. Additionally, the illustrated divider 290 extends radially across at least a portion of the cavity 282 at a location that is in a middle portion of the cavity 282 in between (e.g., in between in the circumferential direction) the liquid cooling ports 280-3 and 280-4. More particularly, in the illustrated embodiment thedivider 290 can extend very close to or contact a perimeter boundary of the cavity 282 at one end close to one or more ports 280-3 and / or 280-4, but has a substantial gap between an opposite end and an opposite portion of the perimeter boundary of the cavity 282 (e.g., in a generally radial direction). The divider 290 limits flow of the liquid coolant within the cavity 282 between regions on opposite sides of the divider 290, without completely blocking liquid flow between those regions. The divider 290 can help to distribute or circulate the liquid coolant within the cavity 282 and around the pin fins 284, to help cool the adjacent portion(s) of the electronics circuitry 270-3 (e.g., the inverter circuitry 270-31), and / or to limit a “short circuit” effect in embodiments where there are multiple bores or ports in relatively close proximity that each directly fluidically communicate with the cavity 282. Moreover, the divider 290, as well as the pin fins 284 and any other structures present in or along the cavity 282, can help tailor the dynamic fluid flow characteristics to help tailor cooling effectiveness. In alternate embodiments, such as shown in FIG. 12B, the divider 290 can be omitted.

[0050] An internal liquid cooling path of the high voltage cooling fan system 252, which forms part of the liquid cooling circuit C, is configurable in a number of different ways. Different ones of the liquid cooling ports 280-1 , 280-2, 280-3, and 280-4 can be connected as inlet and outlet portions to external portions of the liquid cooling circuit C, and other of the ports 280-1, 280-2, 280-3, and 280-4 plugged or sealed, in order to differentially prioritize cooling of either the electronics assembly 270 or the motor assembly 272. For example, either one of the liquid cooling ports 280-1 or 280-2 can be utilized as an inlet port, accepting incoming relatively cool liquid coolant flowable through the liquid cooling circuit C, in order to prioritize cooling of the motor assembly 272 (and the stator 272-2 thereof and winding(s) of that stator 272-2, shown in a simplified schematic manner in FIGS. 10 and 11). Alternatively, either one of the liquid cooling ports 280-3 or 280-4 can instead be utilized as the inlet port in order to prioritize cooling of the electronics assembly 270 (including the inverter circuitry 270-31 and / or other parts of the electronics circuitry 270-3). Furthermore, the sizes (e.g., diameter) of restrictions of the liquid cooling ports 280-1 or 280-2 can each be selected to help balance flow between the cavity 282 and the jacket passage 286 (and thus the cooling of the electronics assembly 270 relative to that of the motor assembly 272) to help optimize temperature reduction while reducing or minimizing system restriction and thus fluid pressure drop. In still further embodiments, a manifold or splitter can be used in the liquid cooling circuit C to deliver liquid coolant to multiple ones of the liquid coolingports 280-1, 280-2, 280-3, and / or 280-4 concurrently (e.g., to two of them), and one or more (e.g., two) of the remaining liquid cooling ports 280-1, 280-2, 280-3, and / or 280-4 can be used as outlets, which can help provide for fluidically parallel liquid cooling sub-paths.

[0051] FIG. 13 illustrates an internal liquid cooling path Cf in a flow simulation in which the liquid cooling port 280-3 is configured as an inlet and the liquid cooling port 280-2 is configured as an outlet, while the liquid cooling ports 280- 1 and 280-4 are plugged, sealed, or alternatively omitted entirely. The internal liquid cooling path Cf flows through the cavity 282 and the jacket passage 286 (which can happen in a combination serial and parallel manner, without a definite series / parallel flow distinction between the cavity 282 and the jacket passage 286). The divider 290 (and / or the pin fins 284) can help promote fluid flow from the cavity 282 to the jacket passage 286 (and back again) through the bores 282-1 and 282-2. The internal liquid cooling path Cf can provide a somewhat balanced distribution of cooling between the cavity 282 and the jacket passage 286, with cooling priority between the cavity 282 and the jacket passage 286 being adjustable by modifying (or omitting) the pin fins 284 and / or the divider 290 and / or other flow restrictions (e.g., the sizes of the bores 282-1 and 282-2).

[0052] FIG. 14 illustrates an internal liquid cooling path Ci” in a flow simulation in which the liquid cooling port 280-3 is configured as an inlet and the liquid cooling port 280-4 is configured as an outlet, while the liquid cooling ports 280-1 and 280-2 are plugged, sealed, or alternatively omitted entirely and the divider 290 is omitted (e.g., with the high voltage power module cooling plate unit having a configuration like that shown in FIG. 12B). The internal liquid cooling path Ci” prioritizes fluid flow within the cavity 282, while still permitting some fluid flow to the jacket passage 286 (which can happen in a combination serial and parallel manner, without a definite series / parallel flow distinction between the cavity 282 and the jacket passage 286). Flow restrictions within portions of the internal liquid cooling path Ci” can be adjusted to ensure that a desired amount of liquid coolant flow passes through the jacket passage 286.

[0053] Discussion of Possible Embodiments

[0054] A system can include: an electric motor assembly; an electronics assembly; an inlet port; an outlet port; and an internal liquid cooling path extending between the inlet port and the outlet port. The electric motor assembly can include: a stator including a winding; a rotor rotatable about an axis and positioned adjacent to the stator; a motor housing, with the stator and the rotor each positioned at least partially within the motor housing; and a jacket passage located in themotor housing and positioned radially outward from the winding. The electronics assembly can include: inverter circuitry electrically connected to the winding to selectively power the electric motor assembly; a housing base, with the inverter circuitry located at least partially within the housing base; and a cavity located at least partially in the housing base, such that the inverter circuitry is located adjacent to the cavity. The internal liquid cooling path can be configured to pass through the jacket passage and the cavity.

[0055] The system of the preceding paragraph can optionally include, additionally and / or alternatively, any one or more of the following features, configurations, and / or additional components:

[0056] a plurality of pin fins that extend into the cavity;

[0057] at least some of the plurality of pin fins can have free ends;

[0058] a cover positioned along the cavity, with the cover arranged at an opposite side of the cavity from the inverter circuitry;

[0059] the free ends of the at least some of the plurality of pin fins can be spaced from the cover by gaps;

[0060] a cover positioned along the cavity, with the cover arranged at a side of the cavity facing the inverter circuitry, and with the plurality of pin fins extending from the cover;

[0061] a divider positioned in the cavity;

[0062] a cover positioned along the cavity, with the cover arranged at a side of the cavity facing the inverter circuitry, and with the divider extending from the cover toward a wall of the housing base;

[0063] a plurality of pin fins that extend from the cover toward the wall of the housing base, with free ends of the plurality of pin fins separated from the wall by gaps;

[0064] a diverter (for example, a wedge-shaped diverter) located in the cavity to disperse liquid coolant flowing along the internal liquid cooling path to different portions of the cavity;

[0065] the jacket passage can have an annular shape and can extend less than 360° around the stator;

[0066] the jacket passage can be tapered;

[0067] the internal liquid cooling path can pass through the jacket passage and the cavity fluidically in series;

[0068] the internal liquid cooling path can pass through the cavity prior to the passing through the jacket passage;

[0069] the jacket passage can extend circumferentially and have opposite circumferential ends separated by a barrier;

[0070] the cavity can have an inlet and an outlet fluidically connected to the inlet and outlet ports, respectively, and a portion of the internal liquid cooling path through the cavity between the inlet and outlet can extend over a greater circumferential distance than does the barrier;

[0071] the internal liquid cooling path can traverse an axial distance between the cavity and the jacket passage;

[0072] the inlet port can be positioned proximate to the cavity, and the outlet port can be positioned proximate the jacket passage and axially offset from the inlet port.;

[0073] the jacket passage can extend circumferentially and have opposite circumferential ends separated by a barrier, and the inlet and outlet ports can be arranged on circumferentially opposite sides of the barrier;

[0074] an output member engaged with the rotor to rotate at the same speed at all times;

[0075] at least one bearing set to rotationally support the output member relative to the motor housing, wherein the at least one bearing set is located at an axially middle portion of the output member;

[0076] an output member engaged with the rotor to rotate when the electric motor assembly produces a torque output;

[0077] a fan connected to the output member; and / or

[0078] the motor housing and the housing base can be attached together such that the electronics assembly and the electric motor assembly form a combined unit.

[0079] A method of cooling an electric motor system can include operating electronic switching circuity, which generates waste heat; absorbing at least a portion of the waste heat in a liquid coolant passing along an internal liquid cooling path through a cavity located adjacent to the electronic switching circuitry; selectively powering an electric motor to generate an output torque as a function of operating the electronic switching circuitry, which further generates waste heat; absorbing at least a portion of the waste heat in the liquid coolant passing along the internal liquid cooling path through a jacket passage located adjacent to and radially outward from awinding of the electric motor; and passing the liquid coolant through an outlet port at a terminus of the internal liquid cooling path after absorbing the waste heat.

[0080] The method of the preceding paragraph can optionally include, additionally and / or alternatively, any one or more of the following features, configurations, and / or additional steps:

[0081] the internal liquid cooling path can pass through the cavity followed by the jacket passage in flow series;

[0082] the internal liquid cooling path can prioritize absorbing the waste heat from electronic switching circuitry over absorbing the waste heat from the winding;

[0083] passing the liquid coolant across an array of pin fins;

[0084] passing the liquid coolant over free ends of an array of pin fins;

[0085] at least partially limiting flow of the liquid coolant along a shortest path between an inlet and an outlet of the cavity;

[0086] distributing the liquid coolant to different regions of the cavity by diverting liquid coolant flow in at least two different directions;

[0087] rotating a fan with the torque output from the electric motor; and / or

[0088] passing the liquid coolant through a heat exchanger to cool the liquid coolant, the heat exchanger being a part of a liquid cooling circuit, and the internal liquid cooling path forming a portion of the liquid cooling circuit.

[0089] A system can include: an electric motor assembly; an electronics assembly; and an internal liquid cooling path. The electric motor assembly can include: a stator; a rotor rotatable about an axis; a motor housing, with the stator and the rotor each positioned at least partially within the motor housing; and a jacket passage located in the motor housing and extending circumferentially around at least a portion of the stator. The electronics assembly can include: inverter circuitry electrically connected to the electric motor assembly; a housing base and a cover forming an enclosure with an internal cavity, with the inverter circuitry located at least partially within the internal cavity of the enclosure; and a liquid cooling cavity in the housing base, the liquid cooling cavity arranged to be axially offset from the jacket passage. The internal liquid cooling path can pass proximate to the inverter circuitry and at least one of the stator and / or the rotor to absorb waste heat, such that a first volume of a liquid coolant passing through internal liquid cooling path absorbs the waste heat from both the inverter circuitry and from at least one of the stator and / or the rotor.

[0090] The system of the preceding paragraph can optionally include, additionally and / or alternatively, any one or more of the following features, configurations, and / or additional components:

[0091] the internal liquid cooling path can pass through the jacket passage and the liquid cooling cavity fluidically in series;

[0092] the jacket passage can be located adjacent to and radially outward from a winding of the stator; and / or

[0093] the liquid cooling cavity can be axially offset from the jacket passage.

[0094] An electric motor system can include: an inlet port at an inlet of an internal liquid cooling path of the electric motor system; electronic switching circuity; a cavity located adjacent to the electronic switching circuitry, wherein the internal liquid cooling path passes through the cavity; an electric motor operably powered by the electronic switching circuitry; a jacket passage located adjacent to and radially outward from a winding of the electric motor, wherein the internal liquid cooling path passes through the jacket passage; and an outlet port at a terminus of the internal liquid cooling path.

[0095] The system of the preceding paragraph can optionally include, additionally and / or alternatively, any one or more of the following features, configurations, and / or additional components:

[0096] the jacket passage can be located downstream of the cavity in flow series along the internal liquid cooling path.

[0097] Summation

[0098] It should be understood that the disclosed embodiments are provided merely by way of example and not limitation. Numerous other embodiments can be envisioned by persons of ordinary skill in the art in view of the entirety of the present disclosure, including the accompanying figures.

[0099] Any relative terms or terms of degree used herein, such as “substantially”, “essentially”, “generally”, “approximately”, and the like, should be interpreted in accordance with and subject to any applicable definitions or limits expressly stated herein. In all instances, any relative terms or terms of degree used herein should be interpreted to broadly encompass any relevant disclosed embodiments as well as such ranges or variations as would be understood by a person of ordinary skill in the art in view of the entirety of the present disclosure, such as to- l-encompass ordinary manufacturing tolerance variations, incidental alignment variations, transient alignment or shape variations induced by thermal, rotational, or vibrational operational conditions, transitory signal fluctuations, and the like. Moreover, any relative terms or terms of degree used herein should be interpreted to encompass a range that expressly includes the designated quality, characteristic, parameter, or value, without variation, as if no qualifying relative term or term of degree were utilized in the given disclosure or recitation.

[0100] The word “comprise”, or variations such as “comprises” or “comprising” are used in an open-ended manner herein and should be interpreted to refer to the inclusion of a stated element, feature, or step, or group of elements, features, or steps, but not the exclusion of any other element, feature, or step, or group of elements, features, or steps. Unless further expressly qualified, use of the word “comprise” or variations thereof does not, alone, exclude the present additional, unrecited elements, steps, or groups of elements or steps. Additionally, unless further expressly qualified, the words “a” and “an” as used herein refer to one or more and do not limit the identified element, feature, step, or the like to one and only one. However, use of the words “a” and “an” herein should be interpreted in accordance with and subject to any applicable further limits expressly stated in the context of any particular instance of usage, without extending such context-specific limits to all other uses generally.

[0101] Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. For example, features disclosed with respect to one embodiment can be utilized with any other disclosed embodiment. As one example, the internal liquid cooling path Cf or Ci” of the high voltage cooling fan system 252 can be utilized with the electronics assembly 170 and the electric motor assembly 172 of the high voltage cooling fan system 152 in further embodiments. And, as a further example, the electric motor assembly 172 can be utilized without liquid cooling, or with a different cooling arrangement in still further embodiments. Moreover, in other embodiments the electric motor assemblies 172 and 272 can have different configurations, such as a different type of synchronous electric motor design, or with the housing base 170-1 and motor housing 172-1 modified such that portions of the housing base 170-1 protrude to define portions of the jacket passage 186 and / or portions of the motor housing 172-1 define at least a portion of the cavity 182.

Claims

CLAIMS:

1. A system comprising: an electric motor assembly including: a stator including a winding; a rotor rotatable about an axis and positioned adjacent to the stator; a motor housing, wherein the stator and the rotor are each positioned at least partially within the motor housing; and a jacket passage located in the motor housing and positioned radially outward from the winding; an electronics assembly including: inverter circuitry electrically connected to the winding to selectively power the electric motor assembly; a housing base, wherein the inverter circuitry is located at least partially within the housing base; and a cavity located at least partially in the housing base, wherein the inverter circuitry is located adjacent to the cavity; an inlet port; an outlet port; and an internal liquid cooling path extending between the inlet port and the outlet port, wherein the internal liquid cooling path passes through the jacket passage and the cavity.

2. The system of claim 1, wherein the electronics assembly further comprises: a plurality of pin fins that extend into the cavity.

3. The system of claim 2, wherein at least some of the plurality of pin fins have free ends.

4. The system of claim 3, wherein the electronics assembly further comprises: a cover positioned along the cavity, wherein the cover is arranged at an opposite side of the cavity from the inverter circuitry, and wherein the free ends of the at least some of the plurality of pin fins are spaced from the cover by gaps.

5. The system of claim 2, wherein the electronics assembly further comprises: a cover positioned along the cavity, wherein the cover is arranged at a side of the cavity facing the inverter circuitry, and wherein the plurality of pin fins extend from the cover.

6. The system of claim 1, wherein the electronics assembly further comprises: a divider positioned in the cavity.

7. The system of claim 6, wherein the electronics assembly further comprises: a cover positioned along the cavity, wherein the cover is arranged at a side of the cavity facing the inverter circuitry, and wherein the divider extends from the cover toward a wall of the housing base; and a plurality of pin fins that extend from the cover toward the wall of the housing base, with free ends of the plurality of pin fins separated from the wall by gaps.

8. The system of claim 1, wherein the electronics assembly further comprises: a diverter located in the cavity to disperse liquid coolant flowing along the internal liquid cooling path to different portions of the cavity.

9. The system of claim 1, wherein the jacket passage has an annular shape and extends less than 360° around the stator.

10. The system of claim 1, wherein the jacket passage is tapered.

11. The system of claim 1, wherein the internal liquid cooling path passes through the jacket passage and the cavity fluidically in series.

12. The system of claim 11, wherein the internal liquid cooling path passes through the cavity prior to the passing through the jacket passage.

13. The system of claim 1, wherein the jacket passage extends circumferentially and has opposite circumferential ends separated by a barrier, wherein the cavity has an inlet and an outlet fluidically connected to the inlet and outlet ports, respectively, and wherein a portion of the internal liquid cooling path through the cavity between the inlet and outlet extends over a greater circumferential distance than does the barrier.

14. The system of claim 1, wherein the internal liquid cooling path traverses an axial distance between the cavity and the jacket passage.

15. The system of claim 1, wherein the inlet port is positioned proximate to the cavity, and wherein the outlet port is positioned proximate the jacket passage and is axially offset from the inlet port.

16. The system of claim 1, wherein the jacket passage extends circumferentially and has opposite circumferential ends separated by a barrier, wherein the inlet and outlet ports are arranged on circumferentially opposite sides of the barrier.

17. The system of claim 1, wherein the electric motor assembly further comprises: an output member engaged with the rotor to rotate at the same speed at all times; and at least one bearing set to rotationally support the output member relative to the motor housing, wherein the at least one bearing set is located at an axially middle portion of the output member.

18. The system of claim 1 and further comprising: an output member engaged with the rotor to rotate when the electric motor assembly produces a torque output; and a fan connected to the output member.

19. The system of claim 1, wherein the motor housing and the housing base are attached together such that the electronics assembly and the electric motor assembly form a combined unit.

20. A method of cooling an electric motor system, the method comprising; operating electronic switching circuity, wherein the operation of the electronic switching circuitry generates waste heat; absorbing at least a portion of the waste heat in a liquid coolant passing along an internal liquid cooling path through a cavity located adjacent to the electronic switching circuitry; selectively powering an electric motor to generate an output torque as a function of operating the electronic switching circuitry, wherein selectively powering the electric motor further generates waste heat; absorbing at least a portion of the waste heat in the liquid coolant passing along the internal liquid cooling path through a jacket passage located adjacent to and radially outward from a winding of the electric motor; and passing the liquid coolant through an outlet port at a terminus of the internal liquid cooling path after absorbing the waste heat.21 . The method of claim 20, wherein the internal liquid cooling path passes through the cavity followed by the jacket passage in flow series.

22. The method of claim 20, wherein the internal liquid cooling path prioritizes absorbing the waste heat from electronic switching circuitry over absorbing the waste heat from the winding.

23. The method of claim 20 and further comprising: passing the liquid coolant across an array of pin fins.

24. The method of claim 23 and further comprising: passing the liquid coolant over free ends of the pin fins.

25. The method of claim 20 and further comprising: at least partially limiting flow of the liquid coolant along a shortest path between an inlet and an outlet of the cavity.

26. The method of claim 20 and further comprising: distributing the liquid coolant to different regions of the cavity by diverting liquid coolant flow in at least two different directions.

27. The method of claim 20 and further comprising: rotating a fan with the torque output from the electric motor.

28. The method of claim 20 and further comprising: passing the liquid coolant through a heat exchanger to cool the liquid coolant, wherein the heat exchanger is part of a liquid cooling circuit, and wherein the internal liquid cooling path forms a portion of the liquid cooling circuit.

29. A system comprising: an electric motor assembly including: a stator; a rotor rotatable about an axis; a motor housing, wherein the stator and the rotor are each positioned at least partially within the motor housing; and a jacket passage located in the motor housing and extending circumferentially around at least a portion of the stator; an electronics assembly including: inverter circuitry electrically connected to the electric motor assembly; a housing base and a cover forming an enclosure with an internal cavity, wherein the inverter circuitry is located at least partially within the internal cavity of the enclosure; and a liquid cooling cavity in the housing base, wherein the liquid cooling cavity is axially offset from the jacket passage; and an internal liquid cooling path that passes proximate to the inverter circuitry and at least one of the stator and / or the rotor to absorb waste heat, such that a first volume of a liquid coolant passing through internal liquid cooling path absorbs the waste heat from both the inverter circuitry and from at least one of the stator and / or the rotor.

30. The system of claim 29, wherein the internal liquid cooling path passes through the jacket passage and the liquid cooling cavity fluidically in series.

31. The system of claim 29, wherein the jacket passage is located adjacent to and radially outward from a winding of the stator, and wherein the liquid cooling cavity is axially offset from the jacket passage.

32. An electric motor system comprising: an inlet port at an inlet of an internal liquid cooling path of the electric motor system; electronic switching circuity; a cavity located adjacent to the electronic switching circuitry, wherein the internal liquid cooling path passes through the cavity; an electric motor with a winding operably powered by the electronic switching circuitry; a jacket passage located adjacent to and radially outward from the winding of the electric motor, wherein the internal liquid cooling path passes through the jacket passage, and wherein the jacket passage is located downstream of the cavity in flow series along the internal liquid cooling path; and an outlet port at a terminus of the internal liquid cooling path.

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