VEHICLE WITH COIL COOLING SYSTEM AND COIL COOLING METHOD

Abstract

Vehicle (16), comprising: a gearbox housing (212) which has a coolant inlet (330); a coil assembly (14, 100) comprising a flange (206) which extends around an edge thereof; a thermally conductive cover (306) with a sealing surface (310) which forms a seal with the flange (206); a cavity (222) defined between the cover (306) and the coil assembly (14, 100) and designed to receive coolant from the coolant inlet (330); and a heat transfer material (406, 506) that is in contact with a surface of the cover (306) and a surface of the gearbox housing (212), wherein the heat transfer material (406, 506) is a solid layer having a thermal conductivity of at least 10 W·m -1 ·K -1exhibits, wherein the solid layer is in a state of compression between the surface of the cover (306) and the surface of the gearbox housing (212).

Description

TECHNICAL AREA

[0001] The present disclosure relates to systems and methods for coil cooling, for example for inverter coils of hybrid or electric vehicles. GENERAL STATE OF THE ART

[0002] In the sense used here, the term "electric vehicle" includes vehicles that incorporate an electric machine for propulsion, such as battery electric vehicles (BEVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs). A BEV includes an electric machine, where the energy source for the electric machine is a rechargeable battery, for example, from an external power grid. In a BEV, the battery is the energy source for propulsion. An HEV includes an internal combustion engine and one or more electric machines, where the energy source for the engine is fuel and the energy source for the electric machine is a battery. In an HEV, the engine can be the primary energy source for propulsion, with the battery providing supplementary energy for propulsion (e.g., for charging).The battery buffers fuel energy and recovers kinematic energy in electrical form. A PHEV is similar to a HEV, but the PHEV can have a larger-capacity battery that can be recharged from the external power grid. In a PHEV, the battery can be the primary energy source for propulsion until it is depleted to a low energy level; from that point on, the PHEV can operate like an HEV for propulsion.

[0003] Electric vehicles may include a voltage converter (DC / DC converter) connected between the battery and the electric motor. Electric vehicles that include AC electric motors may also include an inverter connected between the DC / DC converter and each electric motor. A voltage converter can increase ("step up") or decrease ("step down") the voltage potential to optimize torque performance. The DC / DC converter may include an inductor (or choke) assembly, switches, and diodes. A typical inductor assembly may include a conductive winding wound around a magnetic core. The inductor assembly generates heat as current flows through it. At least some of the generated heat may need to be dissipated for the inductor to operate effectively.

[0004] Document JP 2012-9565A describes a coil cooling structure. Document JP 2005-286020A discloses a water cooling system for a coil system of a HEV (Heat Electrifying Vehicle). Document US 2014 / 0266527A1 describes a vehicle with a coil system and a cooling device for cooling it. Document US 6392519B1 discloses a mounting system for an electromagnetic device with a cooling function. SUMMARY

[0005] In at least one embodiment, a vehicle is provided. The vehicle may include: a gearbox housing having a coolant inlet; a coil assembly comprising a flange extending around an edge thereof; a thermally conductive cover with a sealing surface forming a seal with the flange; a cavity defined between the cover and the coil assembly and designed to receive coolant from the coolant inlet; and a heat transfer material in contact with a surface of the cover and a surface of the gearbox housing.

[0006] The heat transfer material is a solid layer with a thermal conductivity of at least 10 W·m. -1 ·K -1In this embodiment, the heat transfer material can consist of a metal or a thermally conductive polymer. The heat transfer material can have a thickness of 0.5 to 10 mm. A first surface of the heat transfer material can be in contact with a lower surface of the cover over at least 75% of the surface area of ​​the lower surface. At least 95% of a second surface of the heat transfer material can be in contact with the surface of the gearbox housing. The solid layer is in a state of compression between the surface of the cover and the surface of the gearbox housing.

[0007] In another, unclaimed, embodiment, the heat transfer material is a layer of thermally conductive paste having a thermal conductivity of at least 10 W·m. -1 ·K -1The thermally conductive paste can be in contact with a lower surface of the cover over at least 95% of the surface area of ​​the lower surface. The thermally conductive paste can have a thickness of 0.05 to 1 mm. In one embodiment, the thermally conductive cover has a thermal conductivity of at least 10 W / m². -1 ·K -1 The thermally conductive cover can be made of metal. The heat transfer material can be designed to transfer heat from the thermally conductive cover to the surface of the gearbox housing.

[0008] In at least one embodiment, a vehicle is provided. The vehicle may include: a gearbox housing having a coolant inlet; a coil assembly; a thermally conductive cover sealed around an edge of the coil assembly; a cavity defined between the cover and the coil assembly and designed to receive coolant from the coolant inlet; and a compressed solid heat transfer material in contact with a lower surface of the cover and a surface of the gearbox housing.

[0009] The thermally conductive cover can be made of a metal, and the compressed solid heat transfer material can be made of an electrically insulating material. In one embodiment, a first surface of the compressed solid heat transfer material is in contact with the lower surface of the cover over at least 75% of the surface area of ​​the lower surface. The heat transfer material can be made of a thermally conductive polymer.

[0010] In at least one embodiment, a method is provided. The method may include, among other things: in a circulating mode, circulating coolant in a cavity defined between a flange around a coil assembly and a thermally conductive cover sealed to the flange, in order to cool a conductive winding of the coil assembly; and, in an accumulating mode, cooling the conductive winding by transferring heat from it to a vehicle transmission housing via accumulated coolant in the cavity, the thermally conductive cover, and a heat transfer material.

[0011] In circulating mode, the circulating coolant can come into direct contact with the conductive winding, and in accumulating mode, the accumulated coolant can come into direct contact with the conductive winding. In one embodiment, the circulating coolant and the accumulated coolant only come into direct contact with a lower section of the conductive winding; an upper section of the conductive winding is cooled by heat transfer to the lower section of the conductive winding. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a schematic diagram of a plug-in hybrid electric vehicle (PHEV) according to one embodiment; Fig. Figure 2 is a perspective view of a coil assembly according to one embodiment; Fig. Figure 3 is a cross-sectional view of the coil assembly made of Fig. 2; Fig. 4 is a top view of an upper section of a coil cooling system according to one embodiment; Fig. Figure 5 is a side view of the upper section. Fig. 4; Fig. Figure 6 is a perspective view of a base section of a coil cooling system according to one embodiment; Fig. 7 is a top view of the base section from Fig. 6; Fig. Figure 8 is a cross-sectional view of a coil cooling system with a composite upper and base section according to one embodiment; Fig. Figure 9 is a perspective view of an upper section of a coil cooling system according to one embodiment; Fig. 10A is a partially separated view of the upper section from Fig. 9; Fig. 10B is an enlarged view of a section of Fig. 10A; Fig. Figure 11 is a perspective view of a base section of a coil cooling system according to one embodiment; Fig. Figure 12 is a perspective view of a coil cooling system with a composite upper and base section according to one embodiment; Fig. Figure 13 is a cross-sectional view of the coil cooling system made of Fig. 12; Fig. Figure 14 is a cross-sectional view of a coolant inlet flow path of the coil cooling system. Fig. 12 according to one embodiment; Fig. Figure 15 is a bottom view of an upper section of a coil cooling system according to one embodiment; Fig. Figure 16 is a cross-sectional view of a coil cooling system with a composite upper and base section according to one embodiment; Fig. Figure 17 is a cross-sectional view of another coil cooling system with a composite upper and base section according to one embodiment. DETAILED DESCRIPTION

[0012] Depending on the requirements, detailed embodiments of the present invention are disclosed here; it is understood that the disclosed embodiments are merely exemplary for the invention, which can be implemented in various and alternative forms. The figures are not necessarily to scale; some features may be enlarged or reduced to show details of certain components. Accordingly, the specific structural and functional details disclosed here are not to be understood as limiting, but merely as a representative basis for teaching those skilled in the art the diverse uses of the present invention.

[0013] With reference to Fig. Figure 1 shows a transmission 12 in a plug-in hybrid electric vehicle (PHEV) 16, which is an electric vehicle powered by an electric machine 18 with the support of an internal combustion engine 20 and which can be connected to an external power grid. The electric machine 18 can be an AC electric motor that is in Fig. Figure 1 is shown as "power machine" 18. The electric machine 18 receives electrical power and provides drive torque for the vehicle propulsion. The electric machine 18 also functions as a generator to convert mechanical power into electrical power through regenerative braking.

[0014] The gearbox 12 can have a power-split configuration. The gearbox 12 includes the first electric machine 18 and a second electric machine 24. The second electric machine 24 can be an AC electric motor that is in Fig. 1 is depicted as “generator” 24. Like the first electric machine 18, the second electric machine 24 also receives electrical power and provides an output torque. The second electric machine 24 also functions as a generator to convert mechanical power into electrical power and to optimize the power flow through the gearbox 12.

[0015] The gearbox 12 includes a planetary gear unit 26, which comprises a sun gear 28, a planet carrier 30, and a ring gear 32. The sun gear 28 is connected to an output shaft of the second electric machine 24 to obtain generator torque. The planet carrier 30 is connected to an output shaft of the motor 20 to obtain motor torque. The planetary gear unit 26 combines the generator torque with the motor torque and provides a combined output torque around the ring gear 32. The planetary gear unit 26 functions as a continuously variable transmission without fixed or "stage" ratios.

[0016] The gearbox 12 can also include a one-way clutch (OWC) and a generator brake 33. The OWC is coupled to the output shaft of the motor 20 so that the output shaft can only rotate in one direction. The OWC prevents the gearbox 12 from driving the motor 20 in reverse. The generator brake 33 is coupled to the output shaft of the second electric machine 24. The generator brake 33 can be activated to slow down or prevent the rotation of the output shaft of the second electric machine 24 and the sun gear 28. Alternatively, the OWC and the generator brake 33 can be removed and replaced by control strategies for the motor 20 and the second electric machine 24.

[0017] The gearbox 12 includes a countershaft with intermediate gears, comprising a first gear 34, a second gear 36, and a third gear 38. A planetary gear output 40 is connected to the ring gear 32. The planetary gear output 40 engages with the first gear 34 to transmit torque between the planetary gear unit 26 and the countershaft. An output gear 42 is connected to an output shaft of the first electric machine 18.

[0018] The output gear 42 engages with the second gear 36 to transmit torque between the first electric motor 18 and the countershaft. A transmission output gear 44 is connected to a drive shaft 46. The drive shaft 46 is coupled via a differential 50 to a pair of driven wheels 48. The transmission output gear 44 engages with the third gear 38 to transmit torque between the transmission 12 and the driven wheels 48. The transmission also includes a heat exchanger or automatic transmission oil cooler 49 for cooling the transmission oil.

[0019] Vehicle 16 includes an energy storage device, such as a battery 52, for storing electrical energy. The battery 52 is a high-voltage battery capable of supplying electrical power to operate the first electric machine 18 and the second electric machine 24. The battery 52 also receives electrical power from the first electric machine 18 and the second electric machine 24 when they operate as generators. The battery 52 is a battery pack consisting of several (not shown) battery modules, each containing a plurality of battery cells (not shown). Other embodiments of Vehicle 16 incorporate other types of energy storage devices, such as capacitors and fuel cells (not shown), which supplement or replace the battery 52.A high-voltage bus electrically connects the battery 52 to the first electric machine 18 and to the second electric machine 24.

[0020] The vehicle includes a Battery Energy Control Module (BECM) 54 for controlling the battery 52. ​​The BECM 54 receives inputs indicating vehicle and battery conditions, such as battery temperature, voltage, and current. The BECM 54 calculates and estimates battery parameters such as state of charge and capacity. The BECM 54 provides outputs to other vehicle systems and controls (BSOC, P cap ) ready, which indicate a battery state of charge (BSOC) and battery power capacity.

[0021] The gearbox 12 includes a DC / DC converter or variable voltage converter (VVC) 10 and an inverter 56. The VVC 10 and the inverter 56 are electrically connected between the main battery 52 and the first electric machine 18, and between the battery 52 and the second electric machine 24. The VVC 10 raises or increases the voltage potential of the electrical power supplied by the battery 52. ​​It also lowers or decreases the voltage potential of the electrical power supplied by the battery 52. ​​The inverter 56 converts the DC power supplied by the main battery 52 (via the VVC 10) into AC power to operate the electric machines 18 and 24. In addition, the inverter 56 converts AC power, which is provided by the electric machines 18, 24, into DC in order to charge the main battery 52.Other embodiments of the gearbox 12 include multiple inverters (not shown), such as one inverter connected to each electric machine 18, 24. The VVC 10 has a coil assembly 14.

[0022] The transmission 12 includes a transmission control module (TCM) 58 for controlling the electric motors 18, 24, the VVC 10, and the inverter 56. The TCM 58 is designed, among other things, to monitor the position, speed, and power consumption of the electric motors 18, 24. The TCM 58 also monitors electrical parameters (e.g., voltage and current) at various points within the VVC 10 and the inverter 56. The TCM 58 provides output signals to other vehicle systems corresponding to this information.

[0023] Vehicle 16 incorporates a Vehicle System Controller (VSC) 60, which communicates with other vehicle systems and controllers to coordinate their function. Although shown as a single controller, the VSC 60 may include multiple controllers that can be used to control several vehicle systems according to an overall vehicle control logic or software.

[0024] The vehicle control units, including the VSC 60 and the TCM 58, generally contain any number of microprocessors, ASICs, ICs, memories (e.g., FLASH, ROM, RAM, EPROM, and / or EEPROM), and software code to work together to perform a range of operations. The control units also contain predefined data or "translation tables" based on calculations and test data, stored in memory. The VSC 60 communicates with other vehicle systems and control units (e.g., the BECM 54 and the TCM 58) via one or more wired or wireless vehicle connections using common bus protocols (e.g., CAN and LIN). The VSC 60 receives an input (PRND) representing the current position of transmission 12 (e.g., park, reverse, neutral, or drive). The VSC 60 also receives an input (APP) representing the position of the accelerator pedal.The VSC 60 provides the TCM 58 with an output representing a desired wheel torque, a desired motor speed, and a generator brake command; and the BECM 54 with contactor control.

[0025] The vehicle 16 includes a braking system (not shown) comprising a brake pedal, an auxiliary accelerator, a master cylinder, and mechanical links to the driven wheels 48 to effect friction braking. The braking system also includes position sensors, pressure sensors, or a combination thereof to provide information such as the brake pedal position (BPP) corresponding to a braking torque requirement by the driver. The braking system also includes a brake system control module (BSCM) 62, which communicates with the VSC 60 to coordinate regenerative braking and friction braking. The BSCM 62 can provide a regenerative braking command to the VSC 60.

[0026] The vehicle 16 includes an engine control module (ECM) 64 for controlling the engine 20. The VSC 60 provides the ECM 64 with an input (desired engine torque) based on several input signals, including the APP, and corresponding to a need for vehicle propulsion on the part of the driver.

[0027] The vehicle 16 can be configured as a plug-in hybrid electric vehicle (PHEV). The battery 52 receives AC energy at regular intervals from an external power supply or network via a charging port 66. The vehicle 16 also includes an internal charger 68, which receives AC energy from the charging port 66. The charger 68 is an AC / DC converter that converts the received AC energy into DC energy suitable for charging the battery 52. ​​The charger 68 then supplies the battery 52 with DC energy during charging.

[0028] Although the VVC 10 is presented and described in connection with a PHEV 16, it is understood that it can also be implemented in other types of electric vehicles such as an HEV or a BEV.

[0029] The gearbox 12 can also have a gearbox housing. As described above, the motor 20, the power unit 18, and the generator 24 can have output gears that mesh with corresponding gears of the planetary gear unit 26. These mechanical connections can be located within the gearbox housing. A power electronics housing can be mounted on an outer surface of the gearbox 12. The inverter 56 and the TCM 58 can be mounted inside a power electronics housing.

[0030] The VVC 10 is an assembly with components that can be mounted inside and / or outside a gearbox 12. The VVC 10 includes a coil assembly 14. In one embodiment, the coil assembly 14 can be located inside the gearbox housing. In other embodiments, the coil assembly 14 can be located outside or partially outside the gearbox. The VVC 10 can also include several switches and diodes, which are mounted in the power electronics housing located outside the gearbox 12 and which are operatively coupled to the coil assembly 14.

[0031] With reference to Fig. Figures 2-3 show a coil assembly 100, which is an embodiment of the one described in Fig. The coil assembly 100 can be the coil assembly 14 shown in Figure 1. The coil assembly 100 can be mounted at various locations on the vehicle, such as inside the transmission housing, the power electronics housing, or at any other suitable location. The coil assembly 100 has a conductor 102, which can be formed into windings 104. In one embodiment, the conductor 102 is formed into two adjacent tubular windings 104, as shown in the illustration. The coil assembly 100 can also have a core 106 and an insulator 108. The conductor 102, such as the windings 104, can be wound around the core 106, as shown in the illustration. The coil assembly 100 can have the insulator 108, which can be designed as a two-part holder and can hold the conductor 102 and the core 106.In addition, the insulator 108 can physically separate the conductor 102 from the core 106 and can be made of an electrically insulating polymeric material such as polyphenylene sulfide (PPS).

[0032] The conductor 102 can be made of an electrically conductive material such as copper or aluminum and wound into two adjacent helical windings 104. The windings 104 can be formed using an edge-wound winding process with rectangular (or flat) conductive wire. Input and output leads 110 can extend from the conductor 102 and connect to other components.

[0033] In one embodiment, the core 106 can be configured in a double “C” shape, with the core 106 having a first end 112 and a second end 114, each having a curved shape. The core 106 can also have a first leg 116 and a second leg 118 (not shown, opposite leg 116) for connecting the first end 112 to the second end 114 so that together they form an annular core 106. Each leg 116, 118 can have a plurality of core elements 120 spaced apart to define air gaps 122. The core 106 can be made of a magnetic material, such as an iron-based material or alloy. In one embodiment, the core 106 can be made of an iron-silicon alloy powder. Ceramic spacers 124 can be placed between the core elements 120 to maintain the air gaps 122.An adhesive can be applied to the core 106 to hold the ends 112, 114 and the legs 116, 118, including the core elements 120 and spacers 124, in position. Alternatively, a tape (not shown) can be secured around an outer circumference of the core 106 to hold the ends 112, 114 and the legs 116, 118 in position.

[0034] With reference to Fig. Figure 4-8 shows an embodiment of a coil cooling system 200. Fig. 4 and Fig. Figure 5 shows a top view and a side view of an upper section 202 of the system 200, to which the coil assembly 100 belongs. Fig. 6 and Fig. Figure 7 shows a perspective view or a top view of a base section or lower section 204 of the system 200. Fig. Figure 8 shows a cross-section of the 200 system.

[0035] In the representation in Fig. 4 and Fig. In Figure 5, the coil assembly 100 is installed in an upper section 202 of the cooling system 200. The upper section 202 can be coupled to a lower or base section 204, as described in more detail below. Although the system 200 is described as comprising an upper and a lower section, components described as part of one or the other are not limited to this configuration. In addition, more or fewer sections (e.g., 1, 3, 4, etc.) may be present. The coil assembly 100 can be at least partially enclosed at an outer edge or rim by a flange 206. In one embodiment, the flange 206 can enclose the entire coil assembly 100. The flange 206 can run parallel to the coil core 106. The flange 206 can, for example, be injection molded onto the coil assembly 100.In other embodiments, the flange 206 can be attached to the coil assembly by other means, such as an adhesive or mechanical fastener (e.g., screws, rivets, etc.). Another alternative is that the flange 206 is formed from two (or more) parts that interact to form a capsule around the flange 206 (e.g., two halves that interact).

[0036] The upper section 202 can have one or more fastening sections 208, which can also be referred to as retaining projections. The fastening sections 208 can have a passage or a bore 210 designed to receive a fastening element such as a bolt or screw. Depending on the type of fastening element used, the bore 210 can be threaded or smooth. The fastening section(s) 208 can be formed integrally (e.g., as a single piece) with the flange 206, or they can be formed separately and attached using any suitable method (e.g., adhesives or mechanical fasteners). In the embodiment shown, there are two fastening sections 208, one at each end of the upper section 202 or the coil assembly 100 (e.g., on the longitudinal axis). However,The fastening section(s) 208 can be located at any suitable position, and there can be more or fewer than two of them. For example, on the short axis, there can be two fastening sections 208, one on each side, or one fastening section 208 on each side. In one embodiment, the fastening section(s) 208 can extend upward from the flange 206, but not downward from the flange 206. In another embodiment, the fastening section(s) 208 can have a generally hollow cylindrical shape, with the bore 210 located in its center. The fastening section(s) 208 can be designed to allow the upper section 202 to be attached to or secured against the lower or base section 204 of the cooling system 200.

[0037] With reference to Fig. 6 and Fig. Figure 7 shows embodiments of a lower or base section 204 of the cooling system 200. In one embodiment, the base section 204 can be formed on a gearbox housing 212. The base section 204 can have a coil sealing wall 214 extending from a wall, surface, or section of the gearbox housing 212. The coil sealing wall 214 can include an upper sealing surface 216 designed to seal with the flange 206 of the upper section 202. As shown in Figure 7, the base section 204 can be formed on a gear housing 212. The coil sealing wall 214 can include an upper sealing surface 216 designed to seal with the flange 206 of the upper section 202. Fig. As shown in Figure 8, the sealing surface 216 can include a channel, groove, or recess 218 formed therein, which can accommodate a gasket or seal 220. The gasket 220 can be made of a deformable or adaptable material that can form a liquid-tight seal between the flange 206 and the sealing surface 216 when the upper and lower sections of the cooling system 200 are connected and assembled.

[0038] The coil sealing wall 214 can have an outer rim that defines an inner cavity or cooling chamber 222. The sealing wall 214 can be formed integrally with the gear housing 212, so that they are formed in one piece and from the same material. For example, if the gear housing 212 is formed by casting, the sealing wall 214 can be formed integrally with the gear housing 212 as part of the casting process. Alternatively, the sealing wall 214 can be formed separately from the gear housing 212 and attached to a wall, surface, or section of the gear housing 212 at a later time. For example, the sealing wall 214 can be attached to the gear housing by welding, brazing, adhesives, mechanical fastening, or other suitable attachment methods.The sealing wall 214 and the gearbox housing 212, whether integrally formed or subsequently joined, can form the cavity 222, with the gearbox housing 212 forming the lower wall of the cavity 222 and the sealing wall 214 providing the side wall. When the upper and lower sections 202, 204 of the cooling system are combined and assembled, the coil assembly 100 and the flange 206 can form the upper wall of the cavity 222, which can be sealed against coolant fluid except for an inlet 224 and an outlet 226.

[0039] The inlet 224 and outlet 226 allow a coolant, such as automatic transmission fluid (ATF), to enter or exit the cavity 222. The inlet 224 and / or outlet 226 can be formed integrally with the coil sealing wall 214 or attached to it using any suitable method (such as the one described above). In embodiments where the inlet 224 and / or outlet 226 is cast as part of the transmission housing, the channels can also be cast into it or machined into the inlet 224 and / or outlet 226 after casting. The same applies to any other cast-in components disclosed herein in which a bore, channel, passage, etc., is formed. The inlet 224 and outlet 226 can be in contact with the transmission housing 212 and allow the coolant to flow through a wall of it.In the embodiments described in . Fig. As shown in Figures 6-8, the inlet 224 is integral with one side of the sealing wall 214. As shown, the inlet 224 can generally have a cylindrical shape and include a central bore or opening therein to convey the coolant. However, the inlet 224 can have any suitable shape that allows coolant to flow from an external source into the cavity 222. The inlet 224 can extend from the sealing wall 214 (e.g., its outer edge) to a wall or surface of the gearbox housing 212. The inlet 224 can be perpendicular or substantially perpendicular to the wall or surface of the gearbox housing 212. The bore / opening / passage into the inlet 224 can extend through the wall / surface of the gearbox housing 212 (or abut an opening in the wall) and be designed to receive coolant from a pipe, hose, or other conduit.For example, a line can carry coolant from a tank or container, which can be pumped under pressure to the inlet 224 using a pump (e.g. a positive displacement pump).

[0040] The outlet 226 can be formed as part of the sealing wall 214 and extend to a wall or surface of the gearbox housing, for example, to a wall / surface that generally runs parallel to the flange 206 and / or perpendicular to the wall / surface where the inlet 224 is in contact with the coil assembly 100, or opposite to it. The outlet 226 can have a bore / passage / channel therein that extends through the wall or abuts an opening in the wall. The outlet 226 can be designed to transfer coolant from the cavity 222 into a pipe, hose, or other conduit. For example, a conduit can carry the coolant from the outlet 226 to a tank or container, which may be the same tank / container connected to the inlet 224 or a different one.A pump can be incorporated into the system to pump the coolant under pressure to the tank / container. Accordingly, the coolant can be pumped through inlet 224 into cavity 222, pass through cavity 222, and then exit cavity 222 through outlet 226. The coolant can form a closed circuit (e.g., flowing back to the same tank after being pumped out), or it can be pumped to another location (open circuit). One or more heat exchangers (e.g., heaters) can be arranged in the coolant circuit to remove heat from the coolant, thereby enabling its recirculation to cavity 222.

[0041] In one embodiment, the inlet 224 and the outlet 226 can be spaced apart or arranged at opposite ends of the sealing wall 214 or the cavity 222. In the embodiment shown Fig. In the embodiment shown in Figures 6-8, the inlet 224 is shown, for example, on the right side of the sealing wall 214, and the outlet 226 is shown on the left side. This can force the coolant to flow over the cavity 222 and over the windings 104 of the coil assembly 100 (described in more detail below). The inlet 224 and outlet 226 can be located at or near either end of the longitudinal axis of the sealing wall 214.

[0042] The base section 204 of the cooling system 200 may have one or more fastening sections 228, which may be similar to (and also referred to as retaining projections in) the fastening sections 208 of the upper section 202 of the cooling system 200. The fastening sections 228 may have a passage or bore 230 designed to receive a fastening element such as a bolt or screw. Depending on the type of fastening element used, the bore 230 may be threaded or smooth. The fastening section(s) 228 may be formed integrally (e.g., as a single piece) with the sealing wall 214, or they may be formed separately and attached using any suitable method (e.g., adhesives or mechanical fasteners). Alternatively, the fastening sections 228 may be separate from the sealing wall 214.In the illustrated embodiment, two fastening sections 228 are provided, one at each end of the base section 204 (e.g., on the longitudinal axis). However, the fastening section(s) 228 can be located at any suitable position, and there can be more or fewer than two. For example, on the short axis, two fastening sections 228 can be located on one side each, or one fastening section 228 can be located on each side. In one embodiment, the fastening section(s) 228 can extend upwards from a wall of the gearbox housing 212. In another embodiment, the fastening section(s) 228 can have a generally hollow cylindrical shape, in the center of which the bore 230 is located.

[0043] The fastening section(s) 228 of the base section 204 can be designed to align with the fastening section(s) 208 of the upper section 202 of the cooling system 200. The fastening section(s) 228 of the base section 204 can act as supports or beams for holding and receiving the fastening section(s) 208 of the upper section 202. An equivalent number of interacting fastening sections can be present in the upper and base sections. The fastening sections can be designed such that a single fastening element engages with or interacts with a fastening section 208 and a fastening section 228 to secure the upper section 202 to the base section 204.If there are two fastening sections in each of the upper section 202 and the base section 204, then accordingly two fastening elements can secure the upper and base sections to each other.

[0044] With reference to Fig. Figure 8 shows a cross-sectional view of the cooling system 200, in which the upper section 202 is secured to the base section 204. As shown, the sealing surface 216 of the sealing wall 214 can include a channel, groove, or recess 218 in which a gasket or seal 220 can be arranged. Alternatively, the channel / groove / recess can be formed in the base of the flange 206, or both the flange 206 and the sealing surface 216 can have a channel / groove / recess to accommodate the gasket 220. The gasket 220 can form a liquid-tight seal between the flange 206 and the sealing surface 216 when the upper and lower sections of the cooling system 200 are connected and assembled.

[0045] When the upper section 202 is secured to the base section 204, the cavity 222 can be closed / sealed except for the inlet 224 and outlet 226. A lower section 232 (e.g., only the lower section) of the conductor 102, shown as a pair of windings 104, of the coil assembly 100 can be arranged inside the cavity 222 when the system 200 is assembled. An upper section 234 of the conductor 102 can be arranged outside the cavity 222. The flange 206 can be the separating element between the upper and lower sections. As described above, a coolant, such as ATF, other oils, water-glycol mixtures, etc., can be pumped into the cavity 222 through an inlet 224 and exit the cavity 222 through an outlet 226. Accordingly, the coolant can circulate in / through the cavity 222. This means that the lower section 232 of the conductor 102 (e.g.,Since the windings 104 are arranged in the cavity 222, the coolant can be designed to come into direct contact with the lower part of the windings, thereby absorbing and dissipating heat from the windings as the coolant exits the cavity 222. The coolant can then dissipate the absorbed heat at a heat exchanger after exiting through the outlet 226. The coolant can be continuously pumped / circulated through the cavity and over the windings 104 to dissipate heat from the windings. In one embodiment, the coolant can be continuously pumped / circulated while the coil assembly 100 is in operation (e.g., in circulating mode). If the coil assembly 100 is not in operation, the coolant cannot be pumped. During this time, the coolant can accumulate in the cavity 222 (e.g., in accumulating mode).The accumulated coolant can transfer heat from the windings 104 to the gearbox housing 212, thereby providing passive cooling. In some embodiments, however, the coolant can be pumped continuously regardless of whether the coil assembly 100 is operating.

[0046] While the lower section 232 of the conductor / windings can be in direct contact with the coolant, the lower section 234 can be sealed off from the coolant. In one embodiment, the upper section 234 of the conductor can generally be sealed off from the environment, for example, by potting. This can protect the upper section 234 from contamination or potential damage. However, since the conductor / windings 104 are made of a thermally conductive material, heat generated in the upper section 234 can still be dissipated by the coolant in the cavity 222. As heat is dissipated from the lower section 232 of the conductor, the temperature gradient in the conductor will cause heat to be drawn / conducted from the upper section 234 into the lower section 232. This heat can then be dissipated by the coolant as it passes through the cavity 222.

[0047] Accordingly, the following can be added: Fig. The cooling system 200 shown in Figures 6-8 includes a coil assembly mounted on one or more walls / surfaces of a transmission housing. A cavity is formed between the transmission housing and the coil assembly, for example, by a sealing wall integral with the transmission housing and a flange cast onto the coil assembly. The lower portion of the coil assembly can extend into the cavity when the coil assembly is installed. A coolant, such as ATF, can be pumped / circulated into the cavity through an inlet in the transmission housing wall and come into direct contact with windings of the coil assembly to dissipate heat. The coolant can pass through the cavity and exit through an outlet in the transmission housing wall, where it can be cooled (e.g., by means of a heat exchanger) so that it can be reused.The sealed cavity formed between the coil assembly and the gearbox housing allows for continuous, direct cooling of the coil windings while the coil is operating. This cooling system eliminates the need for potting compound, which is used in conventional systems to encase or encase the coil windings and core. Instead, the coil windings (or at least a portion of them) can be cooled directly by the coolant.

[0048] With reference to Fig. Figure 9-14 shows an embodiment of a coil cooling system 300. Fig. 9 and Fig. Figure 10 shows a perspective view or a partially expanded view of an upper section 302 of the system 300, to which the coil assembly 100 belongs. Fig. Figure 11 shows a perspective view of a base section or lower section 304 of the system 300. Fig. Figures 12-14 show several views of the upper and base sections of System 300 after they have been secured and set up. The elements common to Systems 200 and 300 have been labelled with the same reference symbols and do not need to be described again in detail.

[0049] With reference to Fig. 9, Fig. 10A and Fig. Figure 10B shows the upper section 302 of the cooling system 300. Similar to system 200, system 300 may include a coil assembly 100, which may be at least partially enclosed by a flange 206. The upper section 302 may also have one or more mounting sections 208, which may also be referred to as retaining projections. The mounting sections 208 may have a passage or bore 210 designed to receive a fastener such as a bolt or screw. Depending on the type of fastener used, the bore 210 may be threaded or smooth. The mounting section(s) 208 may be formed integrally (e.g., as a single piece) with the flange 206, or they may be formed separately and created using any suitable method (e.g.,adhesives or mechanical fasteners) are attached. In the illustrated embodiment, two fastening sections 208 are provided, one at each end of the upper section 302 or the coil assembly 100 (e.g., on the longitudinal axis). However, the fastening section(s) 208 can be located at any suitable position, and there can be more or fewer than two. For example, on the short axis, two fastening sections 208 can be located on one side each, or one fastening section 208 can be located on each side. In one embodiment, the fastening section(s) 208 can extend upward from the flange 206, but not downward from the flange 206. In another embodiment, the fastening section(s) 208 can have a generally hollow cylindrical shape, in the center of which the bore 210 is located.The fastening section(s) 208 may be designed to allow the upper section 302 to be attached or secured to the lower or base section 304 of the cooling system 300.

[0050] The cooling system 300 may include a coil cover or coil housing 306, which forms a cavity 308 around the lower section 232 of the conductor. This differs from the cooling system 200, in which the cavity 222 around the lower section 232 of the conductor is formed between the coil assembly 100 and the gearbox housing 212. The cover 306 may be made of any suitable material, for example, a thermally conductive material (e.g., a metal such as Al or Cu). However, the cover 306 may also be made of a non-thermally conductive material such as a polymer. The cover 306 may include a sealing surface 310 (similar to the sealing surface 216) designed to contact the flange 206 and provide a seal against it.One or both of the flange 206 and the sealing surface 310 may include a channel, groove, or recess 312 formed therein, which can accommodate a gasket or seal 220. The gasket 220 may be made of a deformable or conformable material that can form a liquid-tight seal between the flange 206 and the sealing surface 310 when the cover 306 is attached to the remainder of the upper section 302. The gasket 220 may be attached (e.g., by means of an adhesive) to one of the covers 306 and the flange 206 before the cover 306 is secured to the flange 206. In the section 306, the gasket 220 is formed. Fig. 10, Fig. 13 and Fig. In the example shown in Figure 14, the gasket 220 is attached to the flange 206 and the sealing surface 310 has the recess 312. When the two components are secured together, a liquid-tight seal is formed.

[0051] The flange 206 in system 300 may differ from the flange in system 200 in that it may have a recess 314 formed therein to allow coolant to flow into the cavity 308. The recess 314 may be designed to correspond to, project beyond, or otherwise communicate with an opening or passage 316 in the cover 306. The opening 316 may be located in or defined within the sealing surface 310 of the cover 306. The cover 306 may have a passage 318 that communicates with the recess 314 and the cavity 308. Together, the recess 314, the opening 316, and the passage 318 may form an inlet flow path 320 that allows the coolant to enter the cavity 308 from the base section 304 of system 300. The coolant can initially enter through openings 316 (e.g.the base section 304) and then enter the recess 314 in the flange 206. From the recess, the coolant can flow through the passage 318 and into the cavity 308. An example of the flow path 320 and the components that form it is shown in . Fig. 10A, Fig. 10B, Fig. 13 and Fig. 14 shown.

[0052] The flange 206 and the cover 306 can have a similar structure to form an outlet flow path 322 through which the coolant exits the cavity 308. For example, the flange 206 can have a recess 324 formed therein to allow the coolant to flow out of the cavity 308. The recess 324 can be designed to correspond to, project beyond, or otherwise communicate with an opening or passage 326 in the cover 306. The opening 326 can be located in or defined within the sealing surface 310 of the cover 306. The cover 306 can have a passage 328 that communicates with the recess 324 and the cavity 308. After entering the cavity 318 from the passage 308, the coolant can pass through the cavity and cool the windings 104.The coolant can then enter the passage 328 and flow into the recess 324. From the recess 324, the coolant can flow through the opening 326 and out of the upper section 302 of the system 300.

[0053] The base section 304 of the system 300 may have one or more fastening sections 228, which may be similar to the fastening sections 208 of the upper section 202 of the cooling system 200 (and may also be referred to as retaining projections, supports, or beams). The fastening sections 228 may have a passage or bore 230 designed to receive a fastening element such as a bolt or screw. Depending on the type of fastening element used, the bore 230 may be threaded or smooth. The fastening section(s) 228 may be formed integrally (e.g., as a single piece) with the gearbox housing 212, or they may be formed separately and attached using any suitable method (e.g., adhesives or mechanical fasteners).In the illustrated embodiment, two fastening sections 228 are provided, one at each end of the base section 304 (e.g., on the longitudinal axis). However, the fastening section(s) 228 can be located at any suitable position, and there can be more or fewer than two. For example, on the short axis, two fastening sections 228 can be located on one side each, or one fastening section 228 can be located on each side. In one embodiment, the fastening section(s) 228 can extend upwards from a wall of the gearbox housing 212. In another embodiment, the fastening section(s) 228 can have a generally hollow cylindrical shape, in the center of which the bore 230 is located.

[0054] The fastening section(s) 228 of the base section 304 can be designed to align with the fastening section(s) 208 of the upper section 302 of the cooling system 300. An equivalent number of cooperating fastening sections can be present in the upper and base sections. The fastening sections can be designed such that a single fastening element engages with or cooperates with a fastening section 208 and a fastening section 228 to secure the upper section 302 to the base section 304. If two fastening sections are present in each of the upper section 302 and the base section 304, then accordingly two fastening elements can secure the upper and base sections to each other.

[0055] The base section 304 can also include a coolant inlet 330, which can be designed to receive coolant from outside the gearbox housing 212 and supply it to the cavity 308. Similar to the mounting sections 228, the coolant inlet 330 can be formed integrally with the gearbox housing, or it can be formed separately and attached using any suitable method (e.g., by means of adhesives or mechanical fasteners). The coolant inlet 330 can also be formed integrally with a mounting section 228, as shown. In one embodiment, the coolant inlet 330 can be cast as part of the gearbox housing. As shown in Fig. As shown in Figures 11-14, the coolant inlet 330 can have a first section 332 extending from a wall / surface of the gearbox housing 212, and a second section 334, which is generally perpendicular to the first section 332 and extends from another wall / surface of the gearbox housing 212. Each section can have a channel or bore 336 defined therein, and the channels 336 can be in fluid communication with each other to form a coolant inlet path 338. As described with respect to the system 200, the coolant inlet 330 can receive coolant from a line that can transfer the coolant from a reservoir or tank to the system 300 via a pump. In embodiments in which the coolant inlet 330 is cast as part of the gearbox housing, the bores 336 can also be cast in or machined in the coolant inlet 330 after casting.The same applies to any other cast-in components disclosed herein in which a bore, channel, passage, etc. is formed.

[0056] The base section 304 may further comprise a coolant outlet 340, which may be designed to receive coolant from the cavity 308 (e.g., through the passage 328) and allow it to flow back from the gearbox housing 212 to the tank or container from which it came, or to a separate location. Similar to the inlet 330, the coolant outlet 340 may be formed integrally with the gearbox housing, or it may be formed separately and attached using any suitable method (e.g., by means of adhesives or mechanical fasteners). The coolant outlet 340 may also be formed integrally with a mounting section 228, as shown. In one embodiment, the coolant outlet 340 may be cast as part of the gearbox housing. As shown in Fig. As shown in Figures 11-14, the coolant outlet 340 can extend from a wall of the gearbox housing 212. The coolant outlet 340 can have a channel or bore 342 defined therein, which can form a coolant outlet path 344.

[0057] The cover 306 can be in contact with the coolant inlet 330 and the coolant outlet 340, forming a seal with them. Similar to the seal between the flange 206 and the cover 306, the coolant inlet 330 can have a sealing surface 346 which may include a channel, groove, or recess 348 formed therein. A gasket or seal 350 can be arranged in the recess 348 to create a liquid-tight seal between the coolant inlet 330 and the cover 306. In one embodiment, the recess 348 and the gasket 350 can enclose the opening 316 in the cover 306, as shown in Fig. 10A, Fig. 10B, Fig. 13 and Fig. Figure 14 shows that, alternatively, the channel / groove / recess can be formed in the base of the cover 306, or both the cover 306 and the sealing surface 346 can have a channel / groove / recess to accommodate the gasket 350. The gasket 350 can form a liquid-tight seal between the cover 306 and the sealing surface 346 when the upper and lower sections of the cooling system 300 are connected and assembled. The cover 306 can similarly contact and seal the coolant outlet 340, which is why the same reference numerals are used.

[0058] When the cooling system 300 is in operation, coolant can enter the cavity 308 and cool the conductor in a similar manner to that described above with respect to the cooling system 200. When the upper section 302 is secured to the base section 304, the cavity 308 can be closed / sealed except for the inlet 330 and outlet 340. A lower section 232 (e.g., only a lower section) of the conductor 102, shown as a pair of windings 104 of the coil assembly 100, can be arranged inside the cavity 308 when the system 300 is assembled. An upper section 234 of the conductor 102 can be arranged outside the cavity 308. The flange 206 can be the separating element between the upper and lower sections. As described above, a coolant such as ATF can contain other oils, water-glycol mixtures, etc.The coolant is pumped / circulated into the cavity 308 via the passage 318 and inlet 330 and exits the cavity 308 through the passage 328 and outlet 340. With the lower section 232 of the conductor 102 (e.g., of the windings 104) located in the cavity 308, the coolant can be designed to come into direct contact with the lower part of the windings, thereby absorbing and dissipating heat from the windings as the coolant exits the cavity 308. The coolant can then dissipate the absorbed heat in a heat exchanger after exiting through the outlet 340. The coolant can be continuously pumped / circulated through the cavity and over the windings 104 to dissipate heat from the windings. In one embodiment, the coolant can be pumped continuously while the coil assembly 100 is in operation (e.g. in circulating mode).If the coil assembly 100 is not in operation, the coolant cannot be pumped / circulated. If it is not pumped / circulated, the coolant can accumulate in the cavity 308 (e.g., in accumulation mode). In some embodiments, however, the coolant can be pumped continuously regardless of whether the coil assembly 100 is operating.

[0059] While the lower section 232 of the conductor / windings can be in direct contact with the coolant, the lower section 234 can be sealed off from the coolant. In one embodiment, the upper section 234 of the conductor can generally be sealed off from the environment, for example, by potting. This can protect the upper section 234 from contamination or potential damage. However, since the conductor / windings 104 are made of a thermally conductive material, heat generated in the upper section 234 can still be dissipated by the coolant in the cavity 308. As heat is dissipated from the lower section 232 of the conductor, the temperature gradient in the conductor will cause heat to be drawn / conducted from the upper section 234 into the lower section 232. This heat can then be dissipated by the coolant as it passes through the cavity 308.

[0060] Accordingly, the following can be added: Fig. The cooling system 300 shown in Figures 9-14 comprises a coil assembly including a cover that encloses a lower portion of the coil windings, which is mounted on one or more walls / surfaces of a transmission housing. A cavity is formed between the cover and the coil assembly, for example, between the cover and a flange cast onto the coil assembly. The lower portion of the coil assembly can extend into the cavity when the coil assembly is installed. A coolant, such as ATF, can be pumped into the cavity through an inlet in the transmission housing wall and subsequently through a flow passage in the flange and cover, and come into direct contact with windings of the coil assembly to dissipate heat.The coolant can pass through the cavity and exit through another flow passage in the flange and cover, and then through an outlet in the gearbox housing wall, where it can be cooled (e.g., by a heat exchanger) so that it can be reused. The sealed cavity formed between the coil assembly and the cover allows for continuous, direct cooling of the coil windings while the coil is operating. This cooling system can eliminate the need for potting compound, which is used in conventional systems to encase or encase the coil windings. Instead, the coil windings (or at least a portion of them) can be cooled directly by the coolant.

[0061] With reference to Fig. Figures 15-16 show an embodiment of a coil cooling system 400. Fig. Figure 15 shows a bottom view of an upper section 402 of the system 400, to which the coil assembly 100 belongs. Fig. Figure 15 shows a perspective sectional view of the upper section 402 and a base section 404 of the system 400 after they have been secured and set up. The elements common to systems 200, 300, and 400 have been designated with the same reference numerals and do not need to be described again in detail. In the embodiment of system 400 shown, the system is essentially the same as the cooling system 300 described above, except that it additionally includes a thermal interface material (TIM) 406, which is described in more detail below. It is understood that the components of system 400 need not be identical to those of system 300. The person skilled in the art will recognize from the present disclosure that certain components of system 400 may be modified, rearranged, or omitted, or that additional components may be present.

[0062] In the representation in Fig. 15 A TIM 406 is arranged on a lower surface 408 of the cover 306. The lower surface 408 of the cover 306 can generally be parallel to the flange 206 and / or the wall / surface of the gearbox housing 212 to which the system 400 is attached. The lower surface 408 can generally be flat. In the illustration in Fig. In Figure 16, the TIM 406 is arranged between the lower surface 408 and a wall / surface of the gearbox housing 212. When the system 400 is assembled, the lower surface 408, the wall of the gearbox housing 212, and the opposing surfaces 410 of the TIM 406 can generally be parallel to each other. When the system 400 is assembled and in use, the TIM 406 can be in contact with the lower surface 408 on one of the opposing surfaces 410 and with the wall / surface of the gearbox housing 212 on the other of the opposing surfaces 410. The TIM 406 can thus enable heat to be transferred from the cover 306 to the gearbox housing 212. The TIM 406 can be a thermally conductive material, for example, a material with a thermal conductivity, as claimed, of at least 10 W / m². -1 ·K -1 , at least 50 W·m -1 ·K -1 or at least 100 W·m -1. K -1If it is not located in a gearbox housing, the TIM 406 can be in contact with another thermally conductive surface instead of the gearbox housing (which may be made of metal).

[0063] As shown, TIM 406 can generally be planar, with a relatively large length and width and a relatively small thickness. In the illustration, TIM 406 is a rectangular prism with a constant thickness, although it can have any suitable shape or be irregular. TIM 406 can be a solid layer of material, for example, a metal (e.g., aluminum or copper) or a conductive polymer (e.g., a polymer composite). However, TIM 406 can also be an unstressed liquid or a high-viscosity paste, for example, a thermal paste. The term thermal paste can refer to a polymerizable liquid matrix containing a thermally conductive filler. Example matrix materials include epoxides, silicones, urethanes, or acrylates, and example fillers include aluminum oxide, boron nitride, or zinc oxide.Alternatives to thermal paste include thermal adhesives, thermally conductive gap fillers, or thermal pads.

[0064] The thickness of TIM 406 can depend on the type of material used. A layer of thermal paste, for example, can be relatively thin, while a metal layer (e.g., Al or Cu) or a thermal pad can be relatively thick. In one embodiment, TIM 406 can have a thickness (e.g., the distance from the cover 306 to the gearbox housing 212) of 0.05 to 10 mm or any range in between. If TIM 406 is, for example, thermal paste or another paste-like substance, then the thickness can be from 0.05 to 2 mm or any range in between, such as 0.05 to 1 mm, 0.05 to 0.5 mm, 0.05 to 0.2 mm, or others. If the TIM 406 is a solid layer, then its thickness can range from 0.5 to 10 mm or any range in between, such as 0.5 to 5 mm, 1 to 10 mm, 1 to 5 mm, or others. The TIM 406 can have a substantially constant thickness.

[0065] The TIM 406 (e.g., one of the surfaces 410) can cover or overlap at least part of the lower surface 408 of the cover 306. The opacity of the TIM 406 can depend on the type of material it is made of. For example, a thermal paste or other paste-like substance can be applied to substantially the entire lower surface 408 (e.g., at least 95%). A solid-layer TIM can have a more geometric shape and may cover as large an area as a paste (although it can). In one embodiment, the TIM 406 can cover or overlap at least 50% of the lower surface 408 (e.g., by area), such as at least 60%, 70%, 75%, 80%, 85%, or 95% of the lower surface 408. The surface 410 of the TIM 406 that is in contact with the gearbox housing can be in substantially complete contact with the gearbox housing (e.g., at least 95% or 100%).

[0066] As described above, the TIM 406 can be in contact with both the lower surface 408 of the cover 306 and a wall of the gearbox housing 212, thereby transferring heat from the former to the latter. If the wall of the gearbox housing 212 is not flat, the TIM 406 can conform to the wall so that it is in contact with the gearbox housing 212 over substantially its entire surface 410. If the TIM 406 is made of a solid material, it can, as claimed, be in a state of compression when the system 400 is assembled and secured to the gearbox housing 212. For example, a gap between the lower surface 408 and the wall of the gearbox housing 212 can be smaller than an unlimited thickness of the TIM 406. Accordingly, the TIM 406 can be compressed and deformed when the TIM 406 is inserted between the two components and the coil assembly 100 is secured to the gearbox housing.In one embodiment, the TIM 406 can be in a state of compression such that its average thickness, when the system 400 is assembled, is at least 1% less than when the system 400 is not assembled, for example 5% or 10% less.

[0067] Accordingly, cooling system 400 can include the cooling characteristics of cooling system 300, plus additional cooling via the heat transfer material (TIM). When coolant, such as ATF or other coolants, is pumped / circulated through cavity 308, the coil windings can be cooled as described above (e.g., the coolant absorbs heat from the windings and is carried away by the coolant flow). However, the coolant does not need to be continuously pumped / circulated at all times. For example, the coolant can be pumped only when the coil is operating or when the vehicle is switched on (e.g., in circulating mode). There may be times when the coolant is not pumped; in this case, it can accumulate in cavity 308 (e.g., in accumulation mode). Cooling of the coil may also be desirable even when the coolant is not circulating.In these situations, the System 400 can transfer more heat from the coil than the System 300.

[0068] In other embodiments, in which the cover 306 is made of a thermally conductive material (e.g., as claimed, at least 10, 50, or 100 W·m²) -1 .K -1(e.g., metal), the system 400 can provide a heat flow path from the coil windings to the stationary / accumulated coolant in the cavity 308, to the cover 306, then to the TIM 406, and finally to the gearbox housing 212. The gearbox housing 212, which is generally made of metal, can act as a heat sink to absorb and dissipate thermal energy from the coil windings. Since the gearbox housing is generally large compared to the coil windings (e.g., with a larger storage mass and / or a larger surface area), it may be able to dissipate the excess heat from the windings without a significant temperature increase. Accordingly, the system 400 can provide passive cooling of the coil windings when no coolant is pumped through the cavity 308 (e.g., in accumulation mode).Some cooling can occur via this heat flow path while the coolant is pumped / circulated, however, the moving coolant may not remain in cavity 308 long enough for significant cooling to occur.

[0069] With reference to Fig. Figure 17 shows an embodiment of a coil cooling system 500. Fig.Figure 17 shows a perspective sectional view of the upper section 502 and a base section 504 of the system 500 after they have been secured and installed. The elements common to systems 200, 300, and 400 have been designated with the same reference numerals and do not need to be described again in detail. In the embodiment of system 500 shown, the system is essentially the same as the cooling system 200 described above, except that the coolant inlet and outlet are omitted and that a heat transfer material (TIM) 506 is additionally present. It is understood that the components of system 500 need not be identical to those of system 200. The person skilled in the art will recognize from the present disclosure that certain components of system 500 may be modified, rearranged, or omitted, or that additional components may be present.

[0070] System 500 cannot provide coolant to the cavity 222 between the gearbox housing 212 and the coil assembly 100 or the flange 206. As described with respect to System 200, a lower section 232 of the conductor 102, shown as a pair of windings 104, of the coil assembly 100 can be arranged inside the cavity 222 when System 200 is assembled. However, instead of using a coolant to cool the lower section 232 of the windings 104, TIM 506 can be used to dissipate the heat. TIM 506 can be the same as that described above with reference to TIM 406. For example, TIM 506 can be a solid layer or an unstressed thermal paste. Since TIM 506 is in contact with the coil windings, it can be made of an electrically insulating material.

[0071] With the lower section 232 of the conductor 102 (e.g., of the windings 104) located in the cavity 222, the TIM 506 can be designed to come into direct contact with the lower part of the windings, thereby absorbing heat from the windings and transferring it to the gearbox housing 212. The gearbox housing 212, which is generally made of metal, can act as a heat sink to absorb and dissipate thermal energy from the coil windings directly via the TIM 506 (e.g., the heat is transferred from the windings to the TIM and then to the gearbox housing). Since the gearbox housing is generally large compared to the coil windings (e.g., with a larger storage mass and / or a larger surface area), it may be able to dissipate the excess heat from the windings without a significant temperature increase.Accordingly, the System 500 can enable passive cooling of the coil windings without any liquid coolant coming into direct contact with the coil assembly (e.g., the windings or the core).

[0072] The TIM 506 can be in contact with both the lower section 232 of the conductor 102 and a wall / surface of the gearbox housing 212, thereby transferring heat from the former to the latter. When the system 500 is assembled and in use, the TIM 506 can be in contact with the lower section 232 of the windings 104 on one of the opposite surfaces 510 and with the wall / surface of the gearbox housing 212 on the other of the opposite surfaces 510. If the wall of the gearbox housing 212 is not flat, the TIM 506 can conform to the wall so that the TIM 506 is in contact with the gearbox housing 212 over substantially its entire surface 410. Likewise, the TIM 506 can conform to the lower section 232 of the windings 104. In at least one embodiment, the TIM 506 can be in contact with the lower section 232 of the coils 104, but not in contact with the core 106 of the coil assembly 100.For example, the lower section 232 of the windings 104 may be the only section of the coil assembly 100 that is in contact with the TIM 506.

[0073] If the TIM 506 is made of a solid material, it may be in a state of compression, as claimed, when the system 500 is assembled and secured to the gearbox housing 212. For example, a gap between the lower section 232 of the windings 104 and the wall of the gearbox housing 212 may be narrower than an unlimited thickness of the TIM 506. Accordingly, the TIM 506 may be compressed and deformed when it is inserted between the two components and the coil assembly 100 is secured to the gearbox housing. For example, the lower section 232 of the windings 104 may extend into the TIM 506 and deform it (e.g., so that the TIM partially encloses the lower section 232 of the windings 104). The TIM 506 may therefore penetrate any gap between the windings (if any).

[0074] In one embodiment, the TIM 506 can be in a state of compression such that its average thickness, when the system 500 is assembled, is at least 1% less than when the system 500 is not assembled, for example, by 5% or 10% less (e.g., at least 1%, 5%, or 10% compressed). Without being bound to any particular theory, it is assumed that the TIM can transfer thermal energy more effectively when it is in a state of compression. Furthermore, applying compression to the TIM can ensure a larger contact area between the lower section 232 of the windings 104 and the TIM, and between the TIM and the gearbox housing.

[0075] The TIM 506 (e.g., one of the surfaces 410) can cover or overlap at least part of the lower section 232 of the windings 104. The opacity of the TIM 506 may depend on the type of material the TIM is made of or on the design of the windings. For example, a paste-like substance can be applied to substantially the entire lower section 232 of the windings 104 (e.g., at least 95%). A solid-layer TIM may have a more geometric shape and may cover an area that is not as large as that of a paste (although it can). In one embodiment, the TIM 506 can cover or superimpose at least 50% of the lower section 232 of the windings 104 (e.g., according to the projected area of ​​the windings), such as at least 60%, 70%, 75%, 80%, 85%, or 95% of the lower section 232 of the windings 104. In another embodiment, the TIM 506 can cover the entire lower section 232 of the windings 104 (e.g.,cover the projected area of ​​the windings).

[0076] Accordingly, the Cooling System 500 can provide passive coil cooling without directly applying liquid coolant to the windings. A heat transfer material (TIM) can be placed in contact with the coil windings on one side and with the gearbox housing on the opposite side. The TIM can absorb heat energy from the coil windings and transfer it to the gearbox housing, which can then dissipate the heat. Additional cooling can be provided by splashing coolant onto the gearbox housing wall opposite the TIM, thereby absorbing some of the heat energy from the gearbox housing. This splashing can be passive (e.g., unintentional or occurring during normal gearbox operation) or active, where the coolant is intentionally directed onto the gearbox housing wall (e.g., by spraying, attaching components, etc.).Passive splashing allows the use of the known design and operation of the gears in the transmission housing. The coolant splashing patterns can be analyzed, and the cooling system 500 can be arranged to collect the splashed coolant. Active splashing can involve providing oil connections in the transmission housing and pumping coolant to the location of the cooling system 500.

Claims

[1] Vehicle (16), comprising: a gearbox housing (212) which has a coolant inlet (330); a coil assembly (14, 100) comprising a flange (206) which extends around an edge thereof; a thermally conductive cover (306) with a sealing surface (310) which forms a seal with the flange (206); a cavity (222) defined between the cover (306) and the coil assembly (14, 100) and designed to receive coolant from the coolant inlet (330); and a heat transfer material (406, 506) that is in contact with a surface of the cover (306) and a surface of the gearbox housing (212), wherein the heat transfer material (406, 506) is a solid layer having a thermal conductivity of at least 10 W·m -1 ·K -1exhibits, wherein the solid layer is in a state of compression between the surface of the cover (306) and the surface of the gearbox housing (212). [2] Vehicle (16) according to claim 1, wherein the heat transfer material (406, 506) consists of a metal or a thermally conductive polymer. [3] Vehicle (16) according to claim 1, wherein the heat transfer material (406, 506) has a thickness of 0.5 to 10 mm. [4] Vehicle (16) according to claim 1, wherein a first surface of the heat transfer material (406, 506) is in contact with a lower surface of the cover (306) over at least 75% of a surface of the lower surface. [5] Vehicle (16) according to claim 4, wherein at least 95% of the surface area of ​​a second surface of the heat transfer material (406, 506) is in contact with the surface of the gearbox housing (212). [6] Vehicle (16) according to claim 1, wherein the thermally conductive cover (306) has a thermal conductivity of at least 10 W·m -1 ·K -1 exhibits. [7] Vehicle (16) according to claim 1, wherein the thermally conductive cover (306) is a metal cover. [8] Vehicle (16) according to claim 1, wherein the heat transfer material (406, 506) is designed to transfer heat from the thermally conductive cover (306) to the surface of the gearbox housing (212). [9] Procedures, comprehensive: in a circulating mode - circulating coolant in a cavity (222) defined between a flange (206) around a coil assembly (14, 100) and a thermally conductive cover (306) sealed to the flange (206) to cool a conductive winding (104) of the coil assembly (14, 100); and in an accumulation mode - cooling of the conductive winding (104) by transferring heat from it to a vehicle transmission housing (212) via accumulated coolant in the cavity (222), the thermally conductive cover (306) and a heat transfer material (406, 506), wherein the heat transfer material (406, 506) is a solid layer having a thermal conductivity of at least 10 W·m -1 ·K -1 exhibits, wherein the solid layer is in a state of compression between the surface of the cover (306) and the surface of the gearbox housing (212).

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