Patent Application
20250007364
The present invention generally relates to high voltage electric fan systems, and components thereof, suitable for cooling applications, as well as associated methods of making and using the same.
Initiatives are underway to limit greenhouse gas emissions and other types of emissions, including CO2 and NOx emissions. 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. The power sources have an energy loss during the conversion of energy. For example, in the case of a battery, there is a loss of energy during the conversion of electricity to or from chemical energy during charging and dis-charging. In the case of a fuel cell, there is an energy loss during the conversion of hydrogen and oxygen to water. In both cases, energy loss in the form of heat (thermal energy) can be substantial and require significant cooling to protect impacted systems from thermal damage. Though particularly in the case of battery-powered vehicles, battery charging operations may have significant cooling demands even when the vehicle is otherwise idle. Operation of auxiliary systems such as supplemental braking mechanisms (e.g., for vehicle operation in mountainous areas) or various other on-board systems may also have cooling demands that extend beyond the basic powertrain and power source cooling demands.
Additionally, such drivetrains are presently intended to operate at high voltages in order to constrain the size of electrical conductors, typically in the range of approximately 650 to 900 volts direct current (VDC). Though because development of these drivetrains is ongoing, other relatively high voltages might be utilized as well, such as even higher voltages. On-board vehicle cooling systems will generally be powered by the same on-board energy sources as the electric powertrain, and will therefore operate at the same high voltages. However, equipment developed for use as electric traction motors in the vehicle powertrain is not readily suited to use in cooling systems. Vehicle traction motors have relatively high torque requirements and take up considerable space. In contrast, cooling systems that provide fan-driven air flows have lower torque requirements, and are subject to substantial space constraints. Bulky and heavy electric traction motor components used in a primary powertrain are therefore ill-suited to use in fan cooling systems that are, essentially, auxiliary systems. On the other hand, lower voltage systems are not directly adaptable to high-voltage use, particularly for use in vehicular applications. Indeed, there is a general lack of high voltage componentry suitable for the torque, space, and mass constraints that apply to fan cooling systems, in addition to a lack of available high voltage electric fan systems (as a whole) suitable for use in vehicular applications.
It is desired to provide a cooling system powered using high voltage electric power that occupies a relatively small amount of space and operates with relatively high efficiency. Such a high voltage cooling system should be suitable for use in vehicular applications, as well as comparable non-vehicular industrial cooling applications. Liquid cooling and a suitable frame for mounting and supporting various components are also desired as part of such a high voltage cooling system. Additionally, accommodation for both high and low voltage electrical components in the same system, while reducing electromagnetic interference and still providing a relatively compact physical electronics assembly, is desired. Moreover, it is desired to provide methods of making and using such a high voltage cooling system.
In one aspect, an electric cooling fan system can include a frame, a first fan, a first electric motor assembly supported by the frame and operably connected to the first fan, a second fan, a second electric motor assembly supported by the frame and operably connected to the second fan, and a liquid cooling path that passes adjacent to both a first stator of the first electric motor assembly and a second stator of the second electric motor assembly such that thermal energy is transferable from the first electric motor assembly and the second electric motor assembly to a liquid coolant present in the liquid cooling path.
In another aspect, a liquid-cooled electric fan system can include an electric motor, a fan, an electronics enclosure, and a liquid cooling channel. The electric motor can include a rotor with a rotor shaft, a stator, and a motor housing. The rotor can be positioned adjacent to the stator, and the motor housing can at least partially surround the rotor and the stator. The fan can be operably connected to the rotor shaft such that a torque output from the electric motor can rotate the fan. The electronics enclosure can be attached to the motor housing, with the electronics enclosure including inverter circuitry electrically connected to the electric motor. The liquid cooling channel can be positioned between the inverter circuitry and the stator, and the liquid cooling channel can contain a liquid coolant capable of accepting thermal energy from one or both of the electric motor and the inverter circuitry.
In another aspect, an electric cooling fan system can include a frame, a first electric motor, and a first fan. The frame can include a pair of crossbars spaced from each other in a substantially parallel arrangement and a plurality of legs each connected to both of the crossbars. At least one of the plurality of legs can include a tube having a nonlinear shape, and all tubular portions of the frame can be closed against liquid incursion. The first electric motor can be attached to both of the crossbars. The first fan can be operably connected to the first electric motor, such that a torque output from the first electric motor can rotate the first fan.
In another aspect, an electric fan system can include an electric motor, a fan, and an electronics assembly. The electric motor can include a rotor, a stator, and a motor housing. The rotor can be positioned adjacent to the stator, and the motor housing can at least partially surround the rotor and the stator. The fan can be operably connected to the electric motor such that a torque output from the electric motor can rotate the fan. The electronics assembly can include a base, a cover attached to the base, a high voltage electrical connector, a low voltage electrical connector, inverter circuitry, and communications circuitry. The base and the cover can enclose an interior volume, and the electric fan system can be configured such that the interior volume is sealed against liquid incursion. The high voltage electrical connector can pass through either the base or the cover, and the low voltage electrical connector can pass through either the base or the cover. The inverter circuitry can be located in the interior volume and electrically connected to both the electric motor and the high voltage electrical connector, and the inverter circuitry can be configured to generate a power output at greater than or equal to 850 Volts DC. The communications circuitry can be located in the interior volume and electrically connected to both the inverter circuitry and the low voltage electrical connector, and the communications circuitry can be configured to operate at less than 500 Volts DC.
An electronics assembly can include an enclosure having an interior volume and being liquid-tight, inverter circuitry located within the interior volume with at least a portion of the inverter circuitry configured to operate at high voltages greater than 600 VDC, communications circuitry located within the interior volume and configured to operate at low voltages less than 500 VDC, high voltage electromagnetic interference (EMI) filter circuitry located within the interior volume and electrically connected between a high voltage power input and the inverter circuitry, and low voltage EMI filter circuitry located within the interior volume and electrically connected between a low voltage power input and the communications circuitry. The high voltage EMI filter circuitry can include at least one common mode choke inductor coil, at least one differential mode X capacitor, and at least one common mode Y capacitor. The low voltage EMI filter circuitry can include at least one common mode choke inductor coil and at least one common mode Y capacitor. The low voltage EMI filter circuitry can have a different configuration than the high voltage EMI filter circuitry.
In yet another aspect, a method of making an electric cooling fan system can include bending metallic tubes to form a plurality of legs having nonlinear shapes, securing a pair of crossbars spaced from each other in a substantially parallel arrangement to each of the plurality of legs, after the pair of crossbars are secured to the plurality of legs, welding end pieces to open ends of the plurality of legs to create a frame, such that all tubular portions of the frame are closed against liquid incursion, attaching a first electric motor assembly to each of the crossbars after the frame is created, and operably connecting a first fan to the first electric motor assembly. Each of the end pieces can have a fastener opening to accept a mechanical fastener suitable to mount the frame at a mounting location.
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.
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. In 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.
In general, the design of the presently-disclosed high voltage electric cooling fan system includes one or more electrically driven fans designed to operate on direct current supply voltages between approximately 500-1200 Volts direct current (VDC), such as at approximately 900 VDC. During operation, the high voltage electric cooling fan system can generate airflows, for instance, moving cooling air past a heat exchanger. The overall system includes at least one fan, a motor assembly, an electronics assembly (with power electronics including a motor drive or inverter, electromagnetic interference filtering hardware, plus communications circuitry, etc.), and structural components sufficient to accept the various components and secure the overall system to a mounting location. In a typical vehicular application, the motor assembly can be secured with a mounting structure that allows it to be mounted to a heat exchanger or some other on-board structural member. In some embodiments, the cooling fan system includes a guard to keep fingers and other appendages or objects from contacting the rotating fan blades. In order to allow for different implementations, the electronics assembly can be positioned differently in relation to the motor assembly. In some embodiments, the motor assembly and an enclosure of the electronics assembly can be structurally attached together as a combined unit while, in other embodiments, the inverter can be remotely mounted and be linked to the motor via cables, hoses, and/or the like. A primary consideration for this difference is the amount of space available for the cooling system, particularly in an axial direction. A liquid cooling circuit can also be provided by the high voltage electric cooling fan system, in order to help regulate thermal operating conditions and cool the electronics assembly and/or the motor assembly. Numerous other features and benefits will be appreciated by those of ordinary skill in the art in light of the entirety of the present disclosure, including the accompanying figures.
In some applications the high voltage electric cooling fan system is carried on board a vehicle with an electrically-powered powertrain, such as inside a motor compartment that could additionally contain an electrically-powered traction motor, at least one heat exchanger assembly, and/or other on-board components. It should be noted, however, that the high voltage electric cooling fan system can also be utilized in non-vehicular industrial cooling applications as well, such as to cool manufacturing equipment in a factory, for example.
The present application claims priority to U.S. provisional patent application Ser. No. 63/269,575, filed Mar. 18, 2022, which is hereby incorporated by reference in its entirety.
The electric motor assembly or assemblies 34-1 to 34-n are each operable to produce torque to drive a corresponding fan 38-1 to 38-n, with variable control over fan speed, rotational direction, and the like. In the embodiment of
The frame 32 supports at least the electric motor assembly or assemblies 34-1 to 34-n, which in turn support the corresponding fan(s) 38-1 to 38-n. The electronics assembly or assemblies 36 or 36-1 to 36-n can be supported by the frame 32 or, alternatively, supported elsewhere (that is, remote from the frame 32), in different embodiments. In the illustrated embodiments, a liquid cooling circuit C is fluidically connected to each of the electric motor assemblies 34-1 to 34-n and each electronics assembly or assemblies 36 or 36-1 to 36-n to form a single or common fluid circuit, though in alternate embodiments multiple, separate liquid cooling circuits could be utilized for certain components of the system 30 or 30′.
The high voltage electric cooling fan system 30 or 30′ is electrically powered by an external power supply (not shown in
It should be noted that
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.
As shown in
A single-fan embodiment of a high voltage electric cooling fan system 130 is shown in
Most of the discussion that follows refers to dual-fan embodiments shown in other figures (see, e.g.,
In general, multi-fan embodiments can include two or more fans and two or more associated high voltage electric fan motors (providing a fan array) that are attached and mounted to a common frame. One advantage of a multi-fan configuration (such as a dual-fan embodiment) is that smaller fans and fan motors can occupy less axial space than a single larger fan with a larger fan motor. The more compact (and, especially, more axially compact) configuration of a multi-fan embodiment can help accommodate packaging and installation space constraints, which are often significant in on-board vehicular applications. The fans and fan motors utilized in multi-fan embodiments can each be the same size and power in some embodiments. Though, in further embodiments, the fans and/or fan motors could alternatively be different sizes (and/or have different power capabilities). Each fan and electric motor assembly in the multi-fan array (see, e.g.,
As shown in the illustrated embodiment, the frame 232 includes first and second crossbars 232C1 and 232C2 (which can also be referred to as main tubes in some embodiments), first and second legs 232L1 and 232L2, and lifting eyelets 232E. The crossbars 232C1 and 232C2 can be arranged substantially parallel to each other and spaced from each other (e.g., spaced vertically) and can extend generally horizontally when the frame 232 is installed at a desired mounting location. The legs 232L1 and 232L2 can each be connected to each of the crossbars 232C1 and 232C2, such as with the legs 232L1 and 232L2 welded or brazed at or near opposite ends of the crossbars 232C1 and 232C2. In the illustrated embodiment, the crossbars 232C1 and 232C2 each have a substantially linear shape and be configured as tubes while the legs 232L1 and 232L2 each have a nonlinear shape with a middle section and ends that are offset from the middle section by way of bends (e.g., curved portions). At least portions of each of the legs 232L1 and 232L2 and/or the crossbars 232C1 and 232C2 can be configured as tubes, that is, hollow, and can be made of a metallic material such as steel. In the illustrated embodiment, tubes forming the legs 232L1 and 232L2 and the crossbars 232C1 and 232C2 have a substantially rectangular (e.g., square) cross-sectional profile. The nonlinear shapes of the legs 232L1 and 232L2 can allow the frame 232 to be mounted to a structure located generally in front of the electric cooling fan system 230 (e.g., a heat exchanger such as the heat exchanger assembly 57 shown in
The frame 232 can also include provisions for lifting the entire electric cooling fan system 230, which can facilitate assembly within a vehicle compartment in which other installed components present obstacles to the maneuvering of the system 230. Because the frame 232 and components of the system 230 carried by it can have a relatively large mass in total, the lifting eyelets 232E can be provided, such as on at least upper ends of the legs 232L1 and 232L2, which can facilitate attaching a lifting mechanism like a hoist or crane to lift and maneuver the frame 232 and frame-supported components of the electric cooling fan system 230 into place in a desired mounting location, such as in a motor compartment of a vehicle, where space constraints due to the presence of other objects may limit maneuverability. The provision of multiple eyelets 232E in different locations can facilitate lifting frame 232 and attached components of the system 230 in different orientations, such as horizontal and vertical. In some embodiments, lifting eyelets facing in different directions (for example, orthogonal to each other) can be provided to allow lifting the system 230 in different orientations, such as with the system 230 in either a horizontal or vertical orientation.
Furthermore, there is a desire to keep moisture out of the inside of the mounting structure in order to prevent internal corrosion. In vehicular and similar applications, for instance, the frame 232 may be exposed to extreme environmental conditions. In some embodiments, for example, one or more tubular portions of the frame 232 can be closed or otherwise sealed to block liquid incursion. As shown in the illustrated embodiment in
Additionally, or in the alternative, thread forming screws or the like can be used to help prevent liquid from entering hollow portions of the frame 232 in embodiments where such screws or similar fastener elements connect the electric motor assemblies 234-1 and 234-2 to the crossbars 232C1 and 232C2 and pierce the tubular crossbars 232C1 and 232C2. However, use of thread forming screws can be limited to only the attachment of relatively smaller components like the electric motor assemblies 234-1 and 234-2, and omitted from attachment points for mounting the entire frame 232 to a desired mounting location, due to the need for greater forces to secure the mass of most or all of the electric cooling fan system 230.
Alternatively, end plugs inserted into and secured to tubular end portions of the legs can be used in further embodiments to provide stiffening to help prevent the leg tubes from collapsing when mounting fasteners (e.g., screws, bolts, rivets, etc.) are tightened. Such end plugs can also act as a barrier for fluids to enter the mounting structure through an end opening or through fastener openings. In some embodiments, fastener openings can pass through both the end plugs and the tubing. In further embodiments, end flanges can be provided at ends of the tubular portions 232T of the legs 232L1 and 232L2 that both close the ends of the tubing (with or without plugs extending into the tubing) and which can provide attachment points oriented at an angle (e.g., at) 90° relative to the tubing of the corresponding leg, such as shown in
The frame 232 can serve multiple functions. First and foremost, the frame 232 supports the fans 238-1 and 238-2 and the electric motor assemblies 234-1 and 234-2 and places them in desired positions relative to a mounting location of the system 230, such as to properly position the fans 238-1 and 238-2 relative to a vehicle heat exchanger assembly (e.g., the heat exchanger assembly 57 of
The first and second electric motor assemblies 234-1 and 234-2 are each high voltage motor assemblies that are capable of generating torque to rotate the corresponding first and second fans 238-1 and 238-2. In the illustrated embodiment, the first and second electric motor assemblies 234-1 and 234-2 are substantially identical to each other and are arranged side-by-side in a horizontal mirror image relationship, although they can differ from each other and/or be arranged differently in further embodiments. Other components of the electric motor assemblies 234-1 and 234-2 are discussed later in the present disclosure. A number of hoses 260A, 260B, and 260C can be provided to connect liquid cooling channels of each of the electric motor assemblies 234-1 and 234-2 to the liquid cooling circuit C. Moreover, cables 262-1 and 262-2 can electrically connect the respective electric motor assemblies 234-1 and 234-2 to the electronics assembly 236, as explained further below. Some or all of the hoses 260A, 260B, and 260C and the cables 262-1 and 262-2 can be secured to the frame 232 with suitable fittings 260F (e.g., harnesses, clamps, tethers, or the like). By attaching components like the electric motor assemblies 234-1 and 234-2 to a frame 232 that has spaced apart crossbars 232C1 and 232C2 and legs 232L1 and 232L2, airflows can pass around, between, and/or through such components, which can facilitate cooling the electric motor assemblies 234-1 and 234-2 and also help to limit obstruction or interference with cooling airflows used to cool nearby objects like the heat exchanger assembly 57 (see
In the illustrated embodiment, the electronics assembly 236 is a shared or common assembly that can control and power both the first and second electric motor assemblies 234-1 and 234-2, and which can be located remotely from the first and second electric motor assemblies 234-1 and 234-2 and the frame 232. That is, in the illustrated embodiment, the electronics assembly 236 is not directly attached to the frame 232 or otherwise supported or carried by the frame 232, but rather is supported at a different, remote mounting location, such as at a different location within a motor compartment of the vehicle 51. Although in further embodiments the electronics assembly 236 could be supported on the frame 232 or otherwise be located in close proximity to the electric motor assemblies 234-1 and 234-2.
The electronics assembly 236 can include an enclosure 250 with a base 250B and a cover 250C, inlet and outlet ports 256A and 256B fluidically connected to a liquid cooling channel 258, a high voltage input connector 264H, a low voltage connector 264L, and output electrical connectors 266-1 and 266-2. Internal components of the electronics assembly 236 are discussed later in the present disclosure. As shown (see also
The cables 262-1 and 262-2 for the electric motor assemblies 234-1 and 234-2 can each be connected to one of the output electrical connectors 266-1 and 266-2 of the electronics assembly 236, and thereby create electrical connections between the electronics assembly 236 and both of the electric motor assemblies 234-1 and 234-2. In this way the cables 262-1 and 262-2 facilitate having the electronics assembly 236 located remotely from the electric motor assemblies 234-1 and 234-2. Suitable electrical cables (not shown) can be connected to the high voltage input connector 264H and the low voltage connector 264L in order to provide power input to electronics within the interior volume of the electronics enclosure 250 and further provide electrical signals for communications, typically via the low voltage connector 264L. The electronics within the interior volume of the electronics enclosure 250 can in turn power and communicate with the electric motor assemblies 234-1 and 234-2 via the output electrical connectors 266-1 and 266-2. In some embodiments, the output electrical connectors 266-1 and 266-2 and/or the low voltage connector 264L can be combined connectors for both electrical power and electrical signal transmission, as explained further later in the present disclosure. Further, electrical grounding can be provided to the electronics assembly 236 through the high voltage input connector 264H and an associated input cable, for example.
The cables 262-1 and 262-2 that electrically connect the electronics assembly 236 to the electric motor assemblies 234-1 and 234-2 can carry both the phase wires to power each electric motor and signal wires to monitor the temperature of associated stator(s). Grounding of the electric motor assemblies 234-1 and 234-2 can also be provided through these same cables 262-1 and 262-2, as discussed further below. The phase wires can carry high voltage current (e.g., 600 VDC or more, such as approximately 900 VDC), whereas the signal wire(s) can operate at significantly lower voltages (e.g., significantly below 500 VDC). Each cable 262-1 and 262-2 can have individual shielded twisted pair wires in addition to an outer shield for the entire cable 262-1 and 262-2. The outer shield of each cable 262-1 and 262-2 can be connected to a cable gland and electrical connector with a 360° attachment. This facilitates an electromagnetic compatibility (EMC) strategy to help meet radiated emissions objectives and requirements.
The liquid cooling channel 258 can extend through at least one wall of the base 250B or the enclosure 250 (e.g., an external wall), and be separated from the interior volume V. In some embodiments, the liquid cooling channel 258 can be located in a bottom external wall of the base 250B opposite the cover 250C and associated opening, although other arrangements are possible in further embodiments. A liquid coolant present in the liquid cooling channel 258 can conductively absorb thermal energy from the electronics assembly 236, such as waste heat from power electronics located within the interior volume V, the heated liquid coolant can flow or be pumped along a liquid flow path in the liquid cooling circuit C to be dissipated, for instance at the radiator 57B (see
During operation, the electronics assembly 236 can drive and control energization of the first and second electric motor assemblies 234-1 and 234-2. An external controller, such as a vehicle controller on-board the vehicle 51, can in turn send signals that control the electronics assembly 236 or are otherwise utilized by the electronics assembly 236 for operation. For instance, an external controller (not shown) can provide a cooling demand signal and/or an enable/disable signal to the electronics assembly 236, which the electronics assembly 236 uses to selectively energize one or both of the electric motor assemblies 234-1 and 234-2 to rotate one or both of the fans 238-1 and 238-2 at desired speed(s), etc., and such control can occur on a fully variable basis.
The first and second fans 238-1 and 238-2 are operatively connected to the first and second electric motor assemblies 234-1 and 234-2, such that the electric motor assemblies 234-1 and 234-2 can selectively rotate the fans 238-1 and 238-2 as governed, at least in part, by the electronics assembly 236. The first and second guards 240-1 and 240-2 can partly or completely enclose the fans 238-1 and 238-2. Because the fans 238-1 and 238-2 might begin rotating unexpectedly, even under conditions when the system 230 is in a vehicle that is not being driven or otherwise moving, the guards 240-1 and 240-2 help prevent nearby persons from having fingers or other appendages too close to the fans 238-1 and 238-2. The guards 240-1 and 240-2 can be supported directly or indirectly by the frame 232. In the illustrated embodiment, the guards 240-1 and 240-2 are only at a rear side of the fans 238-1 and 238-2 but guard covers (not shown) can further be provided at the front of the fans 238-1 and 238-2 to fully enclose them.
The electric motor assembly 234-1 includes a housing 270, a stator 272, and a rotor 274 with a rotor shaft 276. An optional fan adapter 278 can also be provided, to facilitate attachment of the fan 238-1 to the electric motor assembly 234-1. The rotor shaft 276 carries components of the rotor 274 on bearings 280F and 280R, allowing the rotor 274 and the rotor shaft 276 to rotate relative to the stator 272 and the housing 270. Moreover, a temperature sensor (not shown) and/or other sensor(s) can be incorporated into the electric motor assembly 234-1, such as in or near the stator 272. The electric motor assembly 234-1, specifically the rotor 274 and the stator 272, can have a permanent magnet synchronous motor configuration such as a brushless DC (BLDC) design. More specifically, the electric motor assembly 234-1 can be a three phase BLDC design in some embodiments. The stator 272 and the rotor 274 can be procured as a set, using commercially-available components. For instance, in the illustrated embodiment, the stator 272 includes multiple windings (shown only schematically in
In the illustrated embodiment, the stator 272 has three windings out of phase by 120°. The windings of the stator 272 can be situated around steel flux elements to direct a magnetic field during operation. The stator 272 can be potted in a hardened resin to protect it from environmental conditions such as temperature, moisture, and vibration. A sensor, such as a temperature sensor, can also be potted with the stator 272. The stator 272 is generally situated wholly, or at least partially, inside an interior volume of the housing 270.
The rotor 274 of the illustrated embodiment includes the rotor shaft 276 and further includes a number of permanent magnets situated at or near an outer diameter. The permanent magnets are located in the area of the rotor shaft 276 that sits directly radially inside of the stator 272 in the illustrated embodiment. The rotor and associated permanent magnets are also located wholly or at least partially inside the housing 270. The rotor shaft 276 can be longer than the stator 272 and can extend far enough beyond the permanent magnets at each end to place at least one of the bearings 280F and/or 280R between rotor shaft 276 of the rotor 274 and the housing 270. One end of the rotor shaft 276 can extend sufficiently beyond the nearest bearing (e.g., the front bearing 280F) to permit the direct or indirect attachment of the fan 238-1 outside the housing 270 and, in that sense, at least one end of the rotor shaft 276 can extend through and outside of the housing 270. The rotor shaft 276 is rotatable relative to the stator 272 and the housing 270, and defines the axis of rotation A1 of the rotor 274 and the fan 238-1.
In some embodiments, the fan adapter 278 (also called a fan mount) is secured to the rotor shaft 276 and the fan 238-1 is attached to the fan adapter 278, such that the fan 238-1 is indirectly secured to the rotor shaft 276 and rotates with the rotor 274 when the electric motor assembly 234-1 generates a torque output. The fan adapter 278 can be attached at or near one end of the rotor shaft 276, such as at a front end as shown in the illustrated embodiment, in a rotationally fixed manner. When utilized, the fan adapter 278 provides an externally exposed fan mounting location while the permanent magnets of the rotor 274 and the windings of the stator 272 remain enclosed within the housing 270. As shown in
In the illustrated embodiment, the fan 238-1 can include a cup-like center section or hub 238-1H, which can at least partially wrap around the housing 270 of the electric motor assembly 234-1 and which can place a significant portion of the electric motor assembly 234-1 within the axial space of the fan 238-1. Further, the cup-like shape of the hub 238-1H allows blades 238-1B of the fan 238-1 to be positioned axially rearward, such as with leading edges of the blades 238-1B positioned no further axially forward than the front end of the rotor shaft 276 and/or where the fan 238-1 is attached to the fan adapter 278, such as being axially rearward of the fan adapter 278 and/or the front end of the rotor shaft 276. Such a wrap-around configuration helps reduce an axial length of the overall high voltage electric fan cooling system 230. Additionally, the fan 238-1 can be configured to allow stacking when not installed in the system 230, to help reduce space occupied when in storage. During operation, the fan 238-1 is rotationally driven by the rotor shaft 276 when the electric motor assembly 234-1 produces a torque output.
The housing 270 of the electric motor assembly 234-1 can include at least a body (or base) 270B, and, as shown in the illustrated embodiment, can further include a cover 270C (though in alternate embodiments an opening in a housing body of a motor assembly can be covered by a component shared with an enclosure for an electronics assembly, as discussed further below). The body 270B of the housing 270 can provide an interior volume in which the stator 272 and the rotor 274 are positioned, at least partially. In the illustrated embodiment, the body 270B can have a cup-like shape with a rear-facing opening. A seal can be provided between the body 270B and the cover 270C, and motor enclosure provided in part by the housing 270 can be liquid-tight to seal against liquid incursion. The body 270B is the portion that sits generally around the stator 272 and the cover 270C closes the body 270B at an end (e.g., rear end) of the electric motor assembly 234-1. The cover 270C can be secured to the body 270B with suitable fasteners, and, in the illustrated embodiment, the cover 270C includes one or more flanges to allow the housing 270 to be secured to the frame 232 with suitable fasteners. In the illustrated embodiment, the bearing 280R rotatably supports the rotor shaft 276 of the rotor 274 on the cover 270C (or on a shared component that serves as the motor housing cover in alternative embodiments) and the bearing 280F rotatably supports the rotor shaft 276 of the rotor 274 on the body 270B of the housing 270. Suitable bearing pilots 282F and 282R can be provided on the body 270B and the cover 270C, respectively, to accept and help secure the respective bearings 280F and 280R. At least in embodiments in which the electric motor assembly 234-1 and the electronics assembly 236-1 are separated, the cover 270C can further include a cap 284, which can be removable, that allows access to a cavity 286 for terminating motor winding wires (see
The housing 270 (e.g., the cover 270C) can include a provision for cooling. As shown in
The liquid cooling channel 290 can be fabricated, for example, by connecting a series of holes (e.g., by drilling or casting) to create a pathway through the cover 270C (with suitable plugs to create a desired fluid circuit). In the illustrated embodiment, three holes (with suitable end plugs) are provided in the cover in generally a U-shape that surrounds the wire termination cavity 286 on three sides, though other shapes and arrangements are possible in further embodiments.
It should be noted that the shape of the liquid cooling channel 290 is shown merely by way of example and not limitation. Various alternative configurations are possible in further embodiments, such as with more complex serpentine cooling paths. For instance, different numbers and arrangements of passages can be used in the liquid cooling channel 290, and multiple separate cooling channels could also be provided in alternate embodiments. Furthermore, serpentine or other more complexly-shaped passages can be used, which could be created by casting, machining, or other suitable manufacturing processes. Moreover, pins, strips, or other structures can be incorporated in or with the liquid cooling channel 290 to increase the amount of surface area available to conductively transfer thermal energy to the coolant, and/or to generate turbulence to enhance convective cooling effects. Additionally, the liquid cooling channel 290 could pass through the body 270B in further embodiments.
The housing 270 serves many functions. First, the housing 270 provides a mounting structure for securing the electric motor assembly 234-1 to a structural element (such as the frame 232). Second, the housing 270 locates the stator 272 relative to the rotor 274. The housing 270 also conducts heat away from interior components of the electric motor assembly 234-1, such as the stator 272.
While the embodiment of the electric motor assembly 234-1 shown in
In multi-fan embodiments, such as with the electric cooling fan system 230 having a dual fan configuration, the liquid cooling circuit C can have different configurations to provide liquid coolant to the fan motors (e.g., the electric motor assemblies 234-1 and 234-2) and/or the electronics assembly or assemblies (e.g., the electronics assembly 236) either in series or parallel, and combinations of series and parallel portions.
During operation of the series-connected embodiment of
In still further embodiments with more than two fans and more than two electric motor assemblies, it is possible to utilize combinations of series and parallel liquid cooling paths through various portions of the liquid cooling circuit C, such as to have liquid cooling paths through some electric motor assemblies configured in series while liquid cooling paths through other electric motor assemblies are configured in parallel. Furthermore, the liquid cooling path through the liquid cooling channel 258 of the electronics assembly 236 can be fluidically connected to other parts of the liquid cooling circuit C that include the liquid cooling path through the first and second electric motor assemblies 234-1 and 234-2 in either series or parallel, regardless of whether the liquid cooling path through the first and second electric motor assemblies 234-1 and 234-2 is arranged in series (as shown in
Use of liquid cooling, in general, helps protect the components of the electric motor assemblies 234-1 and 234-2, particularly the windings of the stators 272, from thermal damage and degradation. For example, conventional diesel internal combustion engine compartments typically have a 100-110° C. operating range, and the present liquid cooling circuit C can similarly allow components of electric cooling fan system 230 to operate at no more than a 100-110° C. operating range, or, alternatively, at a lower thermal operating range, such as approximately 85° C. or less. Additionally, it has been found that electric fan motor and overall electric cooling fan system 230 efficiency (in terms of torque output) is increased through such liquid cooling of the electric motor assemblies 234-1 and 234-2. For example, testing has shown that initial estimates of approximately 6.2 Nm motor torque outputs were able to be unexpectedly increased to approximately 10.6 Nm as a result of use of the liquid cooling circuit C. Such benefits are realized when the system 230 operates using high voltages.
In general, the enclosure 250 can contain and protect the inverter and communications circuitry 294 and other electrical equipment, such as to protect against environmental conditions that may be experienced in vehicular applications. In some embodiments, the interior volume V of the enclosure 250 can be sealed to be substantially liquid-tight, when the cover 250C is secured, while the various connectors 264H, 264L, 266-1 and 266-2 still allow for electricity and/or electrical signals to be transmitted in and/or out of the interior volume V of the enclosure 250. The seal 294E can be provided between the base 250B and the cover 250C to facilitate liquid-tight scaling. For example, in some embodiments, a hermetic seal is provided by the enclosure 250, while in alternative embodiments only partial sealing is provided. For example, in a further embodiment, the enclosure 250 can include a liquid-tight (e.g., waterproof), air-permeable membrane or valve, which could be located in an opening through the base 250B or the cover 250C. Such a membrane or valve can help account for thermal shock conditions, acceptable air ingress, and/or other conditions that do not pose a risk to components within the interior volume V of the enclosure 250 without compromising the liquid-tight seal. Pressure fluctuations due to thermal shocks might compromise a fully hermetic seal, whereas a semi-permeable membrane, for instance, can help equalize pressures between the interior volume V and exterior environment while still providing protection from potentially damaging liquids.
Low voltage (LV) and high voltage (HV) inputs into the enclosure 250 (and associated connectors 264L and 264H) can be configured with the HV input accepting DC power in a high voltage range of approximately 500-900 Volts DC or more (e.g., at approximately 900 VDC or approximately 850 VDC) and the LV input operating below that high voltage range (e.g., with power and/or electric signals significantly below 500 VDC).
The inverter and communications circuitry 296, and the EMI filter circuitry 298 can be implemented on one or more circuit boards. In the illustrated embodiment of
The inverter and communications circuitry 296, and the inverter circuitry in particular, can be located adjacent to an external wall of the enclosure 250. In the illustrated embodiment, the inverter and communications circuitry 296 (and associated circuit board(s)) are positioned adjacent to a bottom wall of the base 250B of the enclosure 250 in close proximity to the liquid cooling channel 258. Such an arrangement allows for conductive heat transfer to liquid coolant flowable through the liquid cooling channel 258. Inverter circuitry switches high voltage current at a very high frequency. Because of the rapid switching, the inverter portion of the inverter and communications circuitry 296 has energy losses in the form of heat. As such, inverter circuitry 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 inverter and communications circuitry 296, in between the inverter and communications circuitry 296 and the liquid cooling channel 258 and an associated wall of the enclosure 250, to facilitate thermal energy transfer from the inverter and communications circuitry 296 to the liquid coolant present in the liquid cooling channel 258. Because the EMI filter circuitry 298 and/or other electrical components located in the interior volume V of the enclosure 250 tend to generate less waste heat than the inverter circuitry, such components can be arranged inside the interior volume V further away from the liquid cooling channel 258. In further embodiments, however, the liquid cooling channel 258 could extend through multiple walls of the enclosure 250 and/or multiple discrete cooling channels could be provided.
The frame 332 of the illustrated embodiment includes crossbars 332C1 and 332C2 (which can also be referred to as main tubes in some embodiments), legs 332L1 and 332L2, and auxiliary legs 332A1 and 332A2. The frame 332 can be at least partially made of hollow tubing, with certain modifications that make such bent tubing suitable for the conditions experienced in vehicular applications. As shown, the crossbars 332C1 and 332C2 can be generally linear and arranged horizontally, while the legs 332L1 and 332L2 and the auxiliary legs 332A1 and 332A2 can each have nonlinear shapes. The legs 332L1 and 332L2 are arranged and connected at or near the ends of the crossbars 332C1 and 332C2 while the auxiliary legs 332A1 and 332A2 are arranged and connected at middle portions of the crossbars 332C1 and 332C2 with each auxiliary leg 332A1 or 332A2 located directly adjacent to a corresponding one of the combined units U1 or U2. The crossbars 332C1 and 332C2 can have elongate shapes and considerable length to allow the electric motor assemblies 334-1 and 334-2 to be connected and arranged in a side-by-side configuration while still allowing the fans 338-1 and 338-2 to rotate without interference, such as in a side-by-side arrangement with the fans 338-1 and 338-2 having respective axes of rotation A1 and A2 (axis A2 is not visible in the drawings) that can be substantially parallel to each other. Solid ends 332S can be provided at ends of each of the legs 332L1 and 332L2 and the auxiliary legs 332A1 and 332A2 to close the tubular portions of the frame 332 against liquid incursion. In the illustrated embodiment, the solid ends 332S are configured as plates with fastener openings 332F oriented at an angle (e.g., approximately) 90° to the adjacent tubular portion and with a sealed (e.g., welded or brazed) joint 332J between them. The combined units U1 and U2 can be mounted generally in between the crossbars 332C1 and 332C2 and also in between the legs 332L1 and 332L2 and/or the auxiliary legs 332A1 and 332A2. In general, the frame 332 can function similar to the frame 232 as discussed above. Moreover, in some embodiments, the frame 332 can be fabricated by bending the legs 332L; and 332L2 and the auxiliary legs 332A1 and 332A2 to desired shapes, then securing the crossbars 332C1 and 332C2 to the legs 332L1 and 332L2 and/or the auxiliary legs 332A1 and 332A2, such as by welding or brazing or alternatively with mechanical attachments such as fasteners, clamps, or the like, and then, subsequently, the solid end portions 332S can be attached to the legs 332L1 and 332L2 and/or the auxiliary legs 332A1 and 332A2.
In general, components of the electric motor assembly 334-1 and the electronics assembly 336-1 of the combined unit U1 can be similar or identical to those of the electric motor assemblies 234-1 and 234-2 and the electronics assembly 236 described above, with reference numbers generally increased in value by one hundred, with certain exceptions as noted herein regarding integrations as the combined units U1 and U2. For instance, apart from omission of the cover 270C as described further later in the present disclosure, the electric motor assembly 334-1 can be identical or substantially similar to the electric motor assembly 234-1 described above, in some embodiments. However, unlike the system 230, which in the illustrated embodiment uses a single shared (and remotely located) electronics assembly 236 to control and drive multiple electric motor assemblies 234-1 and 234-2, the system 330 can utilize a separately, dedicated electronics assembly 336-1 and 336-2 for each corresponding electric motor assembly 334-1 and 334-2. Components of each of the combined units U1 and U2 can be similar or identical to each other, and in the illustrated embodiment the combined units U1 and U2 differ only with respect to the arrangement of certain electrical connectors and liquid cooling ports. Other aspects of electrical components of the electronics assemblies 336-1 and 336-2 are discussed further elsewhere in this disclosure (see, e.g.,
As shown in the illustrated embodiment of
The electronics assembly 336-1 includes the enclosure 350, which in turn includes the base 350B formed by a plurality of walls and the removable cover 250C to allow access to electrical components located inside (it should be noted that
Also, in the illustrated embodiment the liquid cooling channel 358 is positioned axially in between the stator 372 of the electric motor assembly 334-1 (and the rear end of the rotor shaft 376) and an interior volume V of the electronics assembly enclosure 350 where inverter and communications circuitry 396, EMI filter circuitry 398, and/or other electrical components can be located. Such liquid cooling channel(s) 358 can provide liquid cooling to the electric motor assembly 334-1 in a manner similar to the cooling channels that can be used with the dedicated electric motor assembly 234-1 or 234-2 as described above. Moreover, such liquid cooling channel(s) 358 can be positioned in or adjacent to both assemblies 334-1 and 336-1 in order to concurrently provide cooling to both components of the electronics assembly 336-1 and components of the electric motor assembly 334-1. Additional details of the liquid cooling channel 358 are discussed later in the present disclosure.
A wiring opening 399 can be provided in a wall of the enclosure 350 facing the electric motor assembly 334-1 (e.g., adjacent to the stator 372), and which further can be positioned within a sealing perimeter formed by the seal 394M, for instance. In the illustrated embodiment, the wiring opening 399 has an arcuate, slot shape, like a crescent, with cased and/or rounded edges. The liquid cooling channel 358 can at least partially surround that wiring opening 399 without intersecting the wiring opening 399. Because electrical wiring passing through the wiring opening 399 is protected from environmental conditions, it is not necessary to have exterior, environmentally-protected electrical cables (like the cables 262-1 and 262-2) or connectors (like the connectors 266-1 and 266-2) to connect the electric motor assembly 334-1 to the electronics assembly 336-1.
A cold plate 396C and/or a thermal material (e.g., a thermal paste or thermal pad) 396P can be positioned in between the liquid cooling channel 358 and electrical components in the interior volume V of the enclosure 350, such as the inverter and communications circuitry 396. In the illustrated embodiment (see
As previously discussed, at least one liquid cooling channel 358 can be provided in the shared portion of the electronics assembly enclosure's base 350B. The liquid cooling channel 358 and an associated liquid flow path through the combined unit U1 can be fluidically connected to the liquid cooling channel 358 and associated liquid flow paths through the combined unit U2 in a liquid cooling circuit C of the system 330 either in series or in parallel, in a manner similar or identical to that discussed above with respect to
It is advantageous to mount an inverter circuit board of the inverter and communications circuitry 396, specifically its high-speed inverter switching portion (e.g., IGBTs or SiC MOSFETS), in close proximity to a liquid coolant, such as directly above liquid cooling channel(s) 358 in the wall(s) of the enclosure 350. This liquid cooling path through the liquid cooling channel 358 provides convective cooling via the liquid cooling circuit C as liquid coolant is circulated between the combined units U1 and U2 and a heat exchanger (e.g., the radiator 57B) by a suitable pump (e.g., the circulating pump 30P), as shown in
Packaging the electronics assembly 336-1 with the electric motor assembly 334-1 in the combined unit U1 has several advantages. First, there are fewer electrical connections and cables required in such a configuration. A single high voltage power line (e.g., a single power cable) enters the combined motor assembly/electronics assembly unit U1. The wires that connect the windings of the stator 372 of the electric motor assembly 334-1 to the inverter and communications circuitry 396 of the electronics assembly 336-1 (e.g., passing through the wiring opening 399) can be completely contained within the combined unit U1, which eliminates the need for expensive electrical cables and connectors to link remotely located housings and enclosures in areas that might be exposed to environmental conditions. Such cables and connectors for high voltage applications can be particularly costly due to the unique requirements and demands of high voltage industrial and vehicular applications. The liquid cooling channel 358, which can have a single inlet and single outlet formed by the inlet and outlet ports 356A and 356B in some embodiments, can be used to cool both the electronics assembly 336-1 and the electric motor assembly 334-1 concurrently. This eliminates extra liquid coolant plumbing required when they are separated and each device needs cooling lines to run independently. It is also important to note that extra cooling lines lead to higher pressure losses through the lines and potentially require a larger circulating pump, such that a combined unit can further allow use of a relatively smaller, lighter, and/or less powerful liquid coolant circulating pump (e.g., as the circulating pump 30P as shown in
More details of the electrical components of the electronics assemblies of the inventive high voltage cooling fan system will now be discussed. As already mentioned, the electric motor assemblies are each driven and controlled by an electronics assembly, which can be either dedicated to (and optionally combined with) a corresponding electric motor assembly or shared by multiple electric motor assemblies (and optionally located remotely from the electric motor assemblies). In general, the electronics assembly provides communication with the equipment being cooled by the high voltage electric fan system, such as by communicating with an on-board vehicle computer, communication with various sensor(s) within the high voltage cooling fan system, as well as provides a power electronics subsystem with an inverter to drive fan motor(s), provide electrical filtering functions, etc. The provision of both high voltage and low voltage electrical equipment together, packaged in a way that allows for protection against environmental conditions while also allowing for regulation of thermal operating conditions, control of EMI, and the like, presents a number of challenges that are addressed by embodiments of the presently disclosed high voltage cooling fan system.
As shown, the LV connector 264L is a single integrated input/output connector that includes low voltage power line connections (+/−), configured to operate at low voltages such as below 500 VDC, communications signal line connections such as an “enable” line, high and low communication lines (e.g., for Controller Area Network (CAN) high/low signals), and a plurality of HV interlock loop (HVIL) signal lines. The LV connector 264L can be connected to an external electrical cable (not shown) that can be electrically connected to a low voltage power supply and/or an external controller, such as the external ECU 65 (see
In the illustrated embodiment, LV power input (+/−) electrical connections from the LV connector 264L are made to the LV EMI filter circuitry 298L and then to all of the inverter circuitry 296B1 and 296B2 as well as the communications circuitry 296A. In some embodiments, the communications circuitry 296A can be integrated on one or more circuit boards for the inverter circuitry 296B1 and/or 296B2, such that low voltage power is supplied to the communications circuitry 296A via circuit boards for the inverter circuitry 296B1 and/or 296B2. The enable signal line can be electrically connected to all of the inverter circuitry 296B1 and 296B2. CAN high/low signal lines are electrically connected to the communications circuitry 296A, which in turn is electrically connected to all of the inverter circuitry 296B1 and 296B2. The optional ferrites 297-1, 297-2, 297-3, and 297-4 can be arranged generally after electrical lines have left the LV connector 264L but before those electrical lines reach other electrically connected components such as the LV EMI filter circuitry 298L, the inverter circuitry 296B1 and 296B2, and the communications circuitry 296A. As shown in the illustrated embodiment, the ferrite 297-1 is used for the enable signal line and the LV+ power line, the ferrite 297-2 is used for the LV-power line, the ferrite 297-3 is used for all of the HVIL loop lines, and the ferrite 297-4 is used with the CAN high/low signal lines. In some embodiments, each ferrite 297-1 to 297-4 can comprise a pair of ferrite beads arranged at approximately 90° to each other, and can optionally have a wirewound configuration. The ferrites 297-1 to 297-4 help to reduce noise and interference within the interior volume V. However, use of the ferrites 297-1 to 297-4 is optional and they might be omitted, for instance, when many, most, or all of the electrical components in the interior volume V are provided on printed circuit boards, which tend to reduce ringing and have improved EMI and electromagnetic compatibility (EMC) performance over electrical connections made through individual wires. Other aspects of the ferrites 297-1 to 297-4 are discussed further later in the present disclosure.
The HV connector 264H of the illustrated embodiment includes high voltage power line connections (+/−), configured to operate at high voltages such as at 600 VDC or more (e.g., approximately 850 VDC or approximately 900 VDC), a plurality of HVIL loop signal lines, and a ground line. As shown the HV connector 264H is separate and distinct from the LV connector 264L. The HV connector 264H can be connected to an external electrical cable (not shown) that can be electrically connected to a high voltage power supply and/or an external controller, such as the external ECU 65 (see
In the illustrated embodiment, HV power input (+/−) electrical connections from the HV connector 264H are made to the feedthrough capacitors 295, then to the HV EMI filter circuitry 298H, and then to all of the inverter circuitry 296B1 and 296B2.
The combined electrical connectors 266-1 and 266-1, as shown in the illustrated embodiment, each provide three-phase high voltage power output lines, sensor electrical signal lines, and HVIL loop signal lines. Each combined electrical connector 266-1 or 266-2 can be electrically connected to a corresponding one of the electric motor assemblies 234-1 or 234-2 with a cable 262-1 or 262-2. A ground line could optionally be provided between the electronics assembly 236 and the electric motor assemblies 234-1 and 234-2 through the cables 262-1 and 262-2 in some embodiments. The three-phase high voltage power output lines of a given combined electrical connector 266-1 or 266-1 are electrically connected to corresponding inverter circuitry 296B1 or 296B2, which can each generate high voltage three-phase power output. Moreover, the sensor lines of a given combined electrical connector 266-1 or 266-1 are electrically connected to corresponding inverter circuitry 296B1 or 296B2, which in turn can be electrically connected to the communications circuitry 296A. In general, each combined electrical connector 266-1 or 266-2 can thus be associated with given dedicated inverter circuitry 296B1 or 296B2 and a given electric motor assembly 234-1 or 234-2.
The communications circuitry 296A provides a module that allows the electronics assembly 236 of the high voltage electric cooling fan system 230 to receive instructions or requests from the ECU of the equipment being cooled by the system 230 (e.g., from an on-board vehicle computer such as ECU 65 of vehicle 51) such as rotational speed, rotational direction, and/or other signals that might be relevant, and to externally convey information about operational conditions of the high voltage electric cooling fan system 230. The most common communication protocol for vehicular applications is Controller Area Network (CAN). A typical CAN implementation suitable for use with the presently-disclosed system 230 is defined by the Society of Automotive Engineers (SAE) standard SAE J1939. In one embodiment, CAN signals originating externally are utilized to command general cooling requirements and govern the overall operation of the high voltage fan cooling system 230. The communications circuitry 296A in turn instructs the inverter circuitry 296B1 and/or 296B2, which, in some embodiments, involves converting CAN signals into suitable signals that govern operation of the inverter circuitry 296B1 and/or 296B2. The communications circuitry 296A can be integrated into one or more circuit board(s) for the inverter circuitry 296B1 and/or 296B2, or, alternatively, can be implemented as stand-alone circuitry, such as on a dedicated communications circuit board. In alternate embodiments, the communications circuitry 296A can be a Di+® controller available from Horton, Inc, (Roseville, MN, USA). As already noted, a low voltage communication cable can be electrically connected to the communications circuitry 296A that can be used for electrical communication signals (e.g., CAN signals, sensor signals, etc.) between the electronics assembly 236 and other external devices (e.g., an on-board vehicle computer such as ECU 65). Moreover, sensor signals from the electric motor assemblies 234-1 and/or 234-2 (e.g., a motor temperature signal) can be sent to the communications circuitry 296A, such as via the cables 262-1 or 262-2 and the inverter circuitry 296B1 or 296B2.
The inverter circuitry 296B1 and 296B2 (which can include one or more discrete inverter circuit boards or the like) provides power electronics circuitry modules that each contain high-speed electronic switching devices known as IGBTs or SiC MOSFETs. These devices are able to turn a constant direct current (DC) input voltage signal into a (pseudo-alternating current) pseudo-sinusoidal phased voltage output. Pulse-width modulation (PWM) commands can be used to switch power transistors of the inverter circuitry 296B1 and 296B2 to control on/off intervals to create pulse waves with different widths that are combined into a pseudo sine wave that outputs alternating current (AC) power with varying voltage and frequency. In doing so, three phases of pseudo-sinusoidal signals can be sent to the three windings of the stator 272 of the corresponding electric motor assembly 234-1 or 234-2 causing the stator windings to selectively be energized to generate magnetic fields that interact with the permanent magnets of the rotor 274 to induce rotation and produce torque to rotate the associated cooling fan 238-1 or 238-2. In presently-disclosed embodiments, the inverter circuitry 296B1 and 296B2 can operate at high voltages in the range of approximately 500-1200 Volts DC, such as approximately 600 VDC or more, approximately 850 VDC or more, or approximately 900 VDC or more.
As shown, the LV connector 364L is a single integrated input/output connector that includes low voltage power line connections (+/−), configured to operate at low voltages such as below 500 VDC, communications signal line connections such as an “enable” line, high and low communication lines (e.g., for CAN high/low signals), and a plurality of HVIL loop signal lines. The LV connector 364L can be connected to an external electrical cable (not shown) that can be electrically connected to a low voltage power supply and/or an external controller, such as the external ECU 65 (see
In the illustrated embodiment, LV power input (+/−) electrical connections from the LV connector 364L are made to the LV EMI filter circuitry 398L and then to the inverter circuitry 396B as well as the communications circuitry 396A. In some embodiments, the communications circuitry 396A can be integrated on one or more circuit boards for the inverter circuitry 396B, such that low voltage power is supplied to the communications circuitry 396A via circuit boards for the inverter circuitry 396B. The enable signal line can be electrically connected to the inverter circuitry 396B. CAN high/low signal lines are electrically connected to the communications circuitry 396A, which in turn is electrically connected to the inverter circuitry 396B. The optional ferrites 397-1, 397-2, 397-3, and 397-4 can be arranged generally after electrical lines have left the LV connector 364L but before those electrical lines reach other electrically connected components such as the LV EMI filter circuitry 398L, the inverter circuitry 396B, and the communications circuitry 396A. As shown in the illustrated embodiment, the ferrite 397-1 is used for the enable signal line and the LV+ power line, the ferrite 397-2 is used for the LV-power line, the ferrite 397-3 is used for all of the HVIL loop lines, and the ferrite 397-4 is used with the CAN high/low signal lines. In some embodiments, each ferrite 397-1 to 397-4 can comprise a pair of ferrite beads arranged at approximately 90° to each other, and can optionally have a wirewound configuration. The use of the ferrites 397-1 to 397-4 is optional and they might be omitted, for instance, when many, most, or all of the electrical components in the interior volume V are provided on printed circuit boards. Other aspects of the ferrites 397-1 to 397-4 are discussed elsewhere in the present disclosure.
The HV connector 364H of the illustrated embodiment includes high voltage power line connections (+/−), configured to operate at high voltages such as at 600 VDC or more (e.g., approximately 850 VDC or approximately 900 VDC), a plurality of HVIL loop signal lines, and a ground line. As shown the HV connector 364H is separate and distinct from the LV connector 364L. The HV connector 364H can be connected to an external electrical cable (not shown) that can be electrically connected to a high voltage power supply and/or an external controller, such as the external ECU 65 (see
Grounding for the electronics assembly 336-1 can also be provided through the HV input connector 364H and an associated cable, which can ground at least the external wall of the enclosure 350 and, in turn, the electronics assembly 336-1 can optionally provide grounding to the electric motor assembly 334-1. Additionally, a safety ground 1000 can be provided that also electrically grounds the wall of the enclosure 350. The safety ground 1000 can provide a redundant ground path when the HV connector 364H is connected to ground (e.g., to a vehicle chassis) via an engaged wire or cable.
Three-phase high voltage power output lines, sensor electrical signal lines, and HVIL loop signal lines can pass out of the enclosure 350 of the electronics assembly 336-1 and to the associated electric motor assembly 334-1 through the wiring opening 399, in some embodiments. In embodiments in which the electronics assembly 336-1 and the electric motor assembly 334-1 are provided as a combined unit U1, there is no need to have an external cable and instead simpler interior-grade wires or other similar electrical lines can be used when they are located inside a scaled boundary of the combined unit U1. A ground line could optionally be provided between the electronics assembly 336-1 and the electric motor assembly 334-1 through the wiring opening 399 in some embodiments. The three-phase high voltage power output lines are electrically connected to the inverter circuitry 396B, which can generate high voltage three-phase power output. Moreover, the sensor lines can be electrically connected to the inverter circuitry 396B, which in turn can be electrically connected to the communications circuitry 396A. In general, the inverter circuitry 396B can be electrically connected to a dedicated electric motor assembly 334-1, such as part of the combined unit U1. It should be understood that another combined unit U2 can be provided with another inverter in another enclosure of another electronics assembly 336-2 to power and drive another electric motor assembly 334-2.
The communications circuitry 396A provides a module that allows the electronics assembly 336-1 of the high voltage cooling fan system 330 to receive instructions or requests from the ECU of the equipment being cooled by the system 330 (e.g., from an on-board vehicle computer such as ECU 65 of vehicle 51) such as rotational speed, rotational direction, and/or other signals that might be relevant, and to externally convey information about operational conditions of the high voltage electric cooling fan system 230. For example, SAE standard SAE J1939 can be utilized for CAN communications in one embodiment. In one embodiment, CAN signals originating externally are utilized to command general cooling requirements and govern the overall operation of the high voltage electric cooling fan system 330. The communications circuitry 396A in turn instructs the inverter circuitry 396B, which, in some embodiments, involves converting CAN signals into suitable signals that govern operation of the inverter circuitry 396B. The communications circuitry 396A can be integrated into one or more circuit board(s) for the inverter circuitry 396B, or, alternatively, can be implemented as stand-alone circuitry, such as on a dedicated communications circuit board. In alternate embodiments, the communications circuitry 396A can be a Di+® controller. As already noted, a low voltage cable can be electrically connected to the communications circuitry 396A that can be used for electrical communication signals (e.g., CAN signals, sensor signals, etc.) between the electronics assembly 336-1 and other external devices (e.g., an on-board vehicle computer such as ECU 65). Moreover, sensor signals from the electric motor assembly 334-1 (e.g., a motor temperature signal) can be sent to the communications circuitry 396A, such as via the inverter circuitry 396B. In the illustrated embodiment, the communications circuitry 396A may handle only communications associated with operation of the electric motor assembly 334-1, and not any other electric motor assemblies of the system 330.
The inverter circuitry 396B contains a power electronics circuitry module with high-speed electronic switching devices known as IGBTs or SiC MOSFETs, the operation of which was briefly described already. In general, the inverter can generate three phases of pseudo-sinusoidal signals that can be sent to the three windings of the stator 372 of the corresponding electric motor assembly 334-1 causing the stator windings to selectively be energized to generate magnetic fields that interact with the permanent magnets of the rotor 374 to induce rotation and produce torque to rotate the associated cooling fan 338-1. In presently-disclosed embodiments, the inverter circuitry 396B can operate at high voltages in the range of approximately 500-1200 Volts DC, such as approximately 600 VDC or more, approximately 850 VDC or more, or approximately 900 VDC or more.
Example HV EMI filter circuitry suitable for use as the HV EMI filter circuitry 298H or 398H is shown schematically in
Example LV EMI filter circuitry suitable for use as the LV EMI filter circuitry 298L or 398L is shown schematically in
The HV and LV EMI filter circuitry described with respect to
The ferrite beads 1097A1, 1097A2, 1097B1, 1097B2, 1097C1, and 1097C2 can be generally cylindrical. The holder 1097H can arrange the ferrite beads in pairs (1097A1 and 1097A2; 1097B1 and 1097B2; and 1097C1 and 1097C2) arranged at approximately 90° to each other. Electrical wires W can be wrapped through and around given pairs of the ferrite beads 1097A1 and 1097A2; 1097B1 and 1097B2; and/or 1097C1 and 1097C2 (and parts of the holder 1097H) in a wirewound configuration. For instance, a given set of the wires W can be wrapped in two to three passes, such as three times through and twice around a given pair of the ferrite beads 1097A1 and 1097A2; 1097B1 and 1097B2; or 1097C1 and 1097C2. Use of the ferrite beads 1097A1, 1097A2, 1097B1, 1097B2, 1097C1, and/or 1097C2 can help quiet electrical noise and EMI, particularly for LV circuitry.
In alternative embodiments, the ferrite assembly 1097 could instead be integrated into one or more circuit boards suing on-board ferrite beads or the like.
During operation of the high voltage electric cooling fan system 30, 130, 230, or 330, cooling demand signals from an external system such as the ECU 65 can be received by communications circuitry of a given electronics assembly and used to selectively power one or more associate electric motor assemblies to generate torque to rotate associated fan(s) to achieve desired cooling.
It is generally desirable to control the fan motor(s) to specific speeds, such as a speed setpoint. Increased fan speed will increase the amount of cooling air moved by the fan(s) (for instance, increasing the amount of cooling air that moves across or past a vehicle heat exchanger). But because fan power requirements increase at a cubic rate with speed, it is also desirable to maintain the lowest possible fan speed in order to keep fan power consumption to a relative minimum. Closed loop control can be employed in this situation to spin the fan(s) at a desired speed (or speeds). It is also preferable to keep the fan speed as constant as possible. If the fan speed is hunting or oscillating, it can make a noticeable and undesirable noise. Closed loop control requires the detection of the speed the fan motor is running at. The control electronics will essentially compare the actual speed to the desired speed and then adjust control gain parameters depending on factors such as the difference between actual and desired fan speed, the amount of time the difference is maintained, as well as the rate of change in the speed of the motor. This is commonly referred to as a Proportional, Integral, Derivative (PID) control system. Such control electronics can be provided by one of, or alternatively some combination of, the communications circuitry, the inverter circuitry, and/or an external ECU.
Speed measurement can be achieved without a speed sensor by, for example, measuring a voltage change in each of the motor's phase wires when they are not energized. There are three general states for each of the phase windings during operation. The first is a powered state causing attraction of the magnet on the rotor for propulsion. The second is a de-energizing state where the induced energy in the phase winding is dissipated. The collapse of the magnetic field during this second state causes a spike in voltage from the winding and some current that dissipates the built-up electromagnetic energy. This is known as back electromotive force (back EMF). The final state is where there is no voltage applied to the winding and the induced energy has been dissipated in the second state. During this final state, a change in voltage can be measured due to the movement of magnets on the rotor that are rotationally approaching or moving away from the winding. This is another form of back EMF that is derived from the magnets rotating within the winding of the stator, and is the same principle that is used to generate electricity. The speed of the rotor can be determined by counting the frequency at which this final-state phenomenon occurs. The speed determined by the frequency of the voltage changes in the non-energized windings can then be fed into the PID control loop and used to adjust the control parameters. The sensed fan motor speed can also be sent back through the communications system (and optionally to external systems) for other purposes, such as diagnostics. In further embodiments, other types of sensorless speed measurement techniques can be used, or a speed sensor could be utilized.
In light of the discussion above and the accompanying figures, persons of ordinary skill in the art will appreciate the present invention also includes methods of making and using a high voltage electric cooling fan system, and components thereof. Of note is that electric motor assemblies according to embodiments of the present invention can allow for fabrication using a generally axial stack-up assembly procedure. That is, many of the components can be installed and secured together generally along or substantially parallel to an axis of rotation of the electric motor. This can help simplify assembly. Furthermore, many of the components of embodiments of the high voltage cooling fan system can have a modular, or semi-modular configuration. This allows different components to be utilized in multiple different overall system configurations. For example, the housing body (or base), stator, and rotor of embodiments of the electric motor assembly can be utilized with both remotely located electronics assembly configurations as well as embodiments with a combined unit incorporating both an electronics assembly and an electric motor assembly. Various assemblies are also usable with different numbers of fans, that is, the number of fans and associated motor and electronics assemblies can be scaled up and multiplied as desired for particular applications.
An electric cooling fan system can include: a frame; a first fan; a first electric motor assembly supported by the frame and operably connected to the first fan; a second fan; a second electric motor assembly supported by the frame and operably connected to the second fan; and a liquid cooling path that passes adjacent to both a first stator of the first electric motor assembly and a second stator of the second electric motor assembly such that thermal energy is transferable from the first electric motor assembly and the second electric motor assembly to a liquid coolant present in the liquid cooling path.
The electric cooling fan 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:
A liquid-cooled electric fan system can include: an electric motor including a rotor with a rotor shaft, a stator, and a motor housing, the rotor can be positioned adjacent to the stator, and the motor housing can at least partially surround the rotor and the stator; a fan operably connected to the rotor shaft such that a torque output from the electric motor can rotate the fan; an electronics enclosure attached to the motor housing, the electronics enclosure including inverter circuitry electrically connected to the electric motor; and a liquid cooling channel positioned between the inverter circuitry and the stator, the liquid cooling channel can contain a liquid coolant capable of accepting thermal energy from one or both of the electric motor and the inverter circuitry.
The liquid-cooled electric fan 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:
An electric cooling fan system can include: a frame that includes a pair of crossbars spaced from each other in a substantially parallel arrangement and a plurality of legs each connected to both of the crossbars, at least one of the plurality of legs can comprise a tube having a nonlinear shape, and all tubular portions of the frame can be closed against liquid incursion; a first electric motor attached to both of the crossbars; and a first fan operably connected to the first electric motor.
The electric cooling fan 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:
An electric fan system can include: an electric motor including a rotor, a stator, and a motor housing, with the rotor positioned adjacent to the stator, and with the motor housing at least partially surrounding the rotor and the stator; a fan operably connected to the electric motor such that a torque output from the electric motor can rotate the fan; and an electronics assembly. The electronics assembly can include: a base; a cover attached to the base, such that the base and the cover enclose an interior volume, with the electric fan system (as a whole) configured such that the interior volume is sealed against liquid incursion; a high voltage electrical connector that passes through either the base or the cover; a low voltage electrical connector that passes through either the base or the cover; inverter circuitry located in the interior volume and electrically connected to both the electric motor and the high voltage electrical connector, with the inverter circuitry being configured to generate a power output at greater than or equal to 850 Volts DC; and communications circuitry located in the interior volume and electrically connected to both the inverter circuitry and the low voltage electrical connector, with the communications circuitry being configured to operate at less than 500 Volts DC.
The electric fan 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:
An electronics assembly can include: an enclosure having an interior volume, which can be liquid-tight; inverter circuitry located within the interior volume, with at least a portion of the inverter circuitry configured to operate at high voltages greater than 600 VDC; communications circuitry located within the interior volume, with the communications circuitry configured to operate at low voltages less than 500 VDC; high voltage electromagnetic interference (EMI) filter circuitry located within the interior volume and electrically connected between a high voltage power input and the inverter circuitry, the high voltage EMI filter circuitry including at least one common mode choke inductor coil, at least one differential mode X capacitor, and at least one common mode Y capacitor; and low voltage EMI filter circuitry located within the interior volume and electrically connected between a low voltage power input and the communications circuitry, the low voltage EMI filter circuitry including at least one common mode choke inductor coil and at least one common mode Y capacitor, with the low voltage EMI filter circuitry having a different configuration than the high voltage EMI filter circuitry.
The electronics assembly of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components:
A method of making an electric cooling fan system can include: bending metallic tubes to form a plurality of legs having nonlinear shapes; securing a pair of crossbars spaced from each other in a substantially parallel arrangement to each of the plurality of legs; after the pair of crossbars are secured to the plurality of legs, welding end pieces to open ends of the plurality of legs to create a frame, such that all tubular portions of the frame are closed against liquid incursion, wherein each of the end pieces has a fastener opening to accept a mechanical fastener suitable to mount the frame at a mounting location; attaching a first electric motor assembly to each of the crossbars after the frame is created; and operably connecting a first fan to the first electric motor assembly.
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:
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 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.
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.
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 described or shown with respect to one embodiment can generally be utilized with other disclosed embodiments. Components such as liquid coolant hoses, electrical cables, connectors, ports, supports, and the like can be repositioned in different locations as desired for particular applications. Moreover, certain disclosed features and structures are optional and can be omitted in alternative embodiments. Lastly, persons of ordinary skill in the art will recognize that additional components, features, and steps that are not specifically discussed or illustrated can be utilized with the present invention as desired for particular applications.
| Number | Date | Country | |
|---|---|---|---|
| 63269575 | Mar 2022 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/US2023/064617 | Mar 2023 | WO |
| Child | 18829558 | US |
