Oil-cooled fuel pump motor

Abstract

This invention relates to the field of fuel pump motor technology and discloses an oil-cooled fuel pump motor, which includes: a motor housing with a radially spirally extending spiral cooling channel inside the housing wall, one end of which forms an oil inlet; a motor stator fixed in the inner cavity of the motor housing, the outer circumferential surface of the motor stator being tightly fitted with the inner side of the bottom wall of the spiral cooling channel, and stator winding coils wound on the surface of the motor stator; a motor rotor coaxially fixed to the motor main shaft; a mounting base plate with a driver cooling channel inside, the driver cooling channel being connected to the oil outlet end of the spiral cooling channel; a power module disposed on the outer surface of the mounting base plate; and a composite oil pump, the pump shaft of which is drivenly connected to the motor main shaft, the first oil outlet of the composite oil pump being connected to the oil inlet of the spiral cooling channel. This integrated configuration of motor cooling and driver cooling reduces system size and weight, making the overall structure more compact.

Description

Technical Field

[0001] This invention relates to the field of fuel pump motor technology, and more specifically, to an oil-cooled fuel pump motor. Background Technology

[0002] The fuel pump motor is a core component of the fuel supply system, driving the fuel pump to deliver fuel. The fuel pump motor servo system needs to operate continuously under conditions such as high-speed operation or low-speed high-torque output. The stator winding coil generates copper losses and iron losses, and the driver power module generates conduction losses and switching losses. Both are major heat sources, placing high demands on the cooling system.

[0003] In existing cooling solutions, motor cooling and drive cooling are configured independently, each with its own independent coolant circulation pump, reservoir, and radiator. The oil-cooled motor solution integrates the cooling channel inside the stator core, resulting in a simple channel shape, high processing difficulty, and difficulty in extending to other components such as the drive. After heat dissipation, the heat carried by the cooling medium is directly dissipated to the environment through the radiator, and the changes in the physicochemical properties of the fuel after heating are not utilized.

[0004] The aforementioned existing technologies result in a large overall system size and high weight, making it difficult to meet the requirements of lightweight and high integration. Furthermore, under extreme conditions of low speed and low temperature, both rotor cooling and driver cooling fail, making it impossible to guarantee reliable heat dissipation of the system under these extreme conditions. Summary of the Invention

[0005] This invention provides an oil-cooled fuel pump motor, which solves the technical problems in related technologies where the independent cooling configuration of the motor and the driver leads to a large system size and high weight, as well as cooling failure under extreme conditions of low speed and low temperature.

[0006] This invention discloses an oil-cooled fuel pump motor, comprising: The motor housing has a spiral cooling channel extending radially inside its cylindrical wall. One end of the spiral cooling channel forms an oil inlet, and the other end forms an oil outlet. The motor stator and motor rotor are fixed in the inner cavity of the motor housing. The outer circular surface of the motor stator is in close contact with the inner side of the bottom wall of the spiral cooling channel. The stator winding coil is wound on the surface of the motor stator. The motor rotor is located inside the motor stator and is coaxially fixed to the motor main shaft. It rotates around the motor axis with the motor main shaft. The mounting substrate has a cooling oil return outlet on its side and a driver cooling channel inside the mounting substrate. The oil inlet of the driver cooling channel is connected to the oil outlet of the spiral cooling channel, and the oil outlet of the driver cooling channel is connected to the cooling oil return outlet. The power module is mounted on the outer surface of the mounting substrate; The composite oil pump is fixed to one axial end face of the motor housing. The pump shaft of the composite oil pump is connected to the main shaft of the motor. The first oil inlet of the composite oil pump is connected to the external oil tank. The first oil outlet of the composite oil pump is connected to the oil inlet of the spiral cooling channel. The second oil inlet of the composite oil pump is connected to the cooling return oil outlet. The spiral cooling channel has a bottom wall between it and the inner wall of the motor housing. The inner side of the bottom wall forms the assembly contact surface of the motor stator. The heat generated by the stator winding coil is conducted to the fuel in the spiral cooling channel through the motor stator and the bottom wall. The heat generated by the power module is conducted to the fuel in the driver cooling channel through the wall of the mounting base plate. After cooling, the fuel is delivered to the second inlet of the compound pump through the cooling return oil outlet.

[0007] Furthermore, the spiral cooling channels are provided in multiple ways. These spiral cooling channels are evenly distributed along the circumference of the motor housing cylinder wall and extend synchronously along the axial direction. The oil inlet ends of each spiral cooling channel converge at the same oil inlet, and the oil outlet ends converge at the same outlet. All spiral cooling channels are connected in parallel.

[0008] Furthermore, the driver cooling channel consists of multiple parallel channels formed inside the mounting substrate. The oil inlet of each parallel channel is connected to the outlet of the spiral cooling channel, and the oil outlets of each parallel channel converge and are output to the outside through the cooling return oil outlet. In the mounting substrate area directly below the power module, the spacing between the parallel channels is reduced compared to other areas.

[0009] Furthermore, the axial ends of the stator winding coil are filled with thermally conductive epoxy resin. The thermally conductive epoxy resin is used to isolate the ends of the stator winding coil from the external environment and to conduct the heat generated at the ends of the stator winding coil towards the iron core of the motor stator.

[0010] Furthermore, a driver housing is fixedly mounted on the outer surface of the mounting substrate, and the driver housing covers the power module.

[0011] Furthermore, the motor spindle is a hollow spindle, with an axially penetrating cylindrical inner hole formed inside. A gear ring is provided on the side of the hollow spindle near the composite oil pump, and the gear ring meshes with a gear. The pump shaft of the composite oil pump is connected to the gear shaft via a coupling. A central support rod is provided axially within the inner hole of the hollow spindle, coaxial with the hollow spindle. One end of the central support rod penetrates the hollow spindle and is inserted into a fixed seat on the end cover, where it is circumferentially locked. The other end of the central support rod is located inside the hollow spindle. The central support rod is supported on the inner wall of the hollow main shaft by a sliding bearing. A helical blade is fixedly installed on the portion of the central support rod located inside the hollow main shaft. The inner edge of the helical blade is fixedly connected to the outer surface of the central support rod, and a radial clearance is maintained between the outer edge of the helical blade and the inner wall of the hollow main shaft. The pitch of the helical blade gradually decreases axially from the oil inlet end to the distal end, forming a variable pitch helical surface. When the hollow main shaft rotates, the inner wall of the hollow main shaft rotates relative to the stationary helical blade. The variable pitch helical surface applies an axial thrust component to the fuel, transporting the fuel axially.

[0012] Furthermore, multiple sets of oil slinger holes are distributed axially on the wall surface of the hollow spindle. Each set of oil slinger holes includes a large-diameter oil slinger hole and multiple small-diameter oil slinger holes. The diameter of the large-diameter oil slinger hole is larger than that of the small-diameter oil slinger holes. Both the large-diameter and small-diameter oil slinger holes radially penetrate the wall surface of the hollow spindle. A temperature-controlled sealing element is installed inside the large-diameter oil slinger hole. The temperature-controlled sealing element adopts a wax-type thermal expansion plunger structure, including a wax cavity and a plunger. The wax cavity is fixedly embedded in the radial outer end of the large-diameter oil slinger hole. The wax chamber contains a phase change wax. One end of the plunger is inserted into the wax chamber and contacts the phase change wax, while the other end extends inward along the radial direction of the large-diameter oil slinger. The plunger and the wall of the large-diameter oil slinger form a sliding pair. At low temperatures, the phase change wax is in a solid state, the plunger retracts into the wax chamber, and the large-diameter oil slinger is fully open. When the fuel temperature rises to the phase change temperature of the phase change wax, the phase change wax expands and pushes the plunger to extend inward along the radial direction to block the large-diameter oil slinger. Fuel is only sprayed out from the small-diameter oil slinger.

[0013] Furthermore, the mounting substrate has a jet chamber located below the power module. A jet orifice plate is fixed within the jet chamber, dividing it into an oil inlet space and an impact space. The oil inlet space is connected to the driver cooling channel. A micro-pore array is distributed on the jet orifice plate. A bypass orifice is formed at the edge of the jet orifice plate, with a diameter larger than that of the micro-pore array. A wax-type thermal expansion element and a temperature-controlled on / off valve core are installed within the bypass orifice. The wax cavity shell of the wax-type thermal expansion element is fixedly embedded within the bypass orifice. At one end of the impact side space of the bypass orifice, one end of the temperature-controlled valve core abuts against the power output end of the wax-type thermal expansion element, and the other end of the temperature-controlled valve core is connected to a spring. The other end of the return spring abuts against the stepped surface at one end of the oil inlet side space of the bypass orifice. In the low temperature state, the return spring drives the temperature-controlled valve core to retract towards the impact side space, and the bypass orifice is in the fully open state. When the fuel temperature rises to the wax phase change temperature of the wax-type thermal expansion element, the wax expands and pushes the temperature-controlled valve core to extend towards the oil inlet side space to block the bypass orifice.

[0014] Furthermore, a grid-shaped guide rib is provided at the outlet of the impact side space of the bypass orifice. The grid-shaped guide rib is fixed to the edge of the orifice of the bypass orifice, which splits the fuel entering the impact side space through the bypass orifice into multiple fine streams.

[0015] Furthermore, a diversion valve is provided at the parallel diversion node of the rotor cooling circuit and the driver cooling circuit. The valve body of the diversion valve has a valve hole along the axial direction, and a slidable valve core is installed in the valve hole. The side wall of the valve body has a rotor oil supply port communicating with the rotor cooling circuit and a driver oil supply port communicating with the driver cooling circuit. When the slid valve core slides along the axial direction, the shoulder of the slid valve core changes the effective opening area of ​​the rotor oil supply port and the driver oil supply port. One end of the slid valve core abuts against a shape memory spring, and the other end of the shape memory spring is fixed to the inner wall of the valve body end cap. The shape memory spring is thermally coupled to the mounting base plate through a heat-conducting component. The other end of the slid valve core faces the back pressure feedback hole of the rotor cooling circuit, and this end of the slid valve core abuts against a resistance spring. The other end of the resistance spring is fixed to the inner wall of the end cap at the other end of the valve body. At low temperature, the shape memory spring is in a contracted state, and the slid valve core is biased towards the position that increases the effective opening area of ​​the rotor oil supply port under the action of the resistance spring. As the system temperature rises, the shape memory spring extends and pushes the slid valve core to gradually increase the effective opening area of ​​the driver oil supply port and simultaneously decrease the effective opening area of ​​the rotor oil supply port.

[0016] This invention solves the technical problems of large system size and heavy weight caused by separate configurations of motor cooling and driver cooling by using a metal additive manufacturing process to integrally form a spiral cooling channel on the motor housing, integrally forming a mounting base with the motor housing and connecting it in series with the spiral cooling channel, and directly driving the composite oil pump from the motor spindle. It achieves the technical effects of sharing a common fuel cooling oil circuit, reducing the number of fluid circuit components, and making the overall structure more compact. By directly delivering the cooled and heated fuel to the engine combustion chamber, it achieves the technical effect of converting waste heat into fuel enthalpy to participate in the thermodynamic cycle and avoiding ineffective emission into the environment. Furthermore, by setting fixed spiral blades inside the hollow spindle to provide axial pumping force through rotational shearing, it solves the problem of... The technical problem of insufficient centrifugal force causing rotor cooling circuit failure at low speeds has been solved, achieving the technical effect of still generating effective axial pumping pressure at extremely low speeds. Through the coordinated cooperation of the rotor-side oil slinger hole group and temperature control sealing element, and the bypass large hole on the driver side and temperature control opening and closing valve core, the technical problem of synchronous failure of the two cooling circuits under low temperature and high viscosity conditions has been solved, achieving the technical effect of adaptively switching cooling modes without external control signals. Through the diversion valve, the technical problem of the limited pumping capacity being evenly distributed under low speed and low temperature combined conditions, resulting in each circuit failing to meet the minimum cooling flow requirement, has been solved, achieving the technical effect of continuously and adaptively adjusting the flow distribution ratio of the two circuits according to the heat load distribution characteristics. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall mechanism of the oil-cooled fuel pump motor of the present invention; Figure 2 This is the invention Figure 1 A schematic diagram of the front structure of the Sinopec cold fuel pump motor; Figure 3 This is a longitudinal sectional view of the oil-cooled fuel pump motor of the present invention; Figure 4 This is a cross-sectional view of the oil-cooled fuel pump motor of the present invention; Figure 5 This is a longitudinal sectional view of the jet cooling structure inside the mounting substrate of the present invention; Figure 6 This is a cross-sectional view of the diversion valve of the present invention.

[0018] In the diagram: 1. Motor housing; 2. Motor stator; 3. Stator winding coil; 4. Motor rotor; 5. Hollow spindle; 6. End cover; 7. Spiral cooling channel; 8. Composite oil pump; 9. Coupling; 10. Mounting base plate; 11. Power module; 12. Pad; 13. Driver housing; 15. Central support rod; 16. Spiral blade; 17. Fixing seat; 18. Oil slinger hole assembly; 19. Large-diameter oil slinger hole; 20. Small-diameter oil slinger hole; 21. Temperature control sealing element; 22. Jet orifice plate; 23. Bypass orifice; 24. Wax-type thermal expansion element; 25. Temperature control on / off valve core; 26. Return spring; 27. Grille-shaped guide rib; 28. Diverter valve; 29. ​​Slide valve core; 30. Shape memory spring; 31. Oil inlet; 33. Cooling oil return outlet; 34. Gear; 35. Resistance spring. Detailed Implementation

[0019] In the propulsion systems of aerospace vehicles, the stator winding coil 3 of the fuel pump motor servo system generates copper and iron losses during high-speed operation, while the driver power module 11 generates conduction and switching losses, both of which are major heat sources. Existing cooling solutions configure motor cooling and driver cooling separately, each requiring independent coolant circulation pumps, reservoirs, and radiators. This results in a large overall system size and weight, failing to meet the lightweight and high integration requirements of aerospace equipment. Furthermore, existing oil-cooled motor solutions integrate cooling channels inside the stator core. Limited by the core structure and traditional processing techniques, the channel shape is simple, manufacturing is difficult, and the channels cannot be extended to other components such as the driver, failing to form a system-level synergistic cooling solution covering both the motor and driver. Simultaneously, after the existing cooling system dissipates heat, the heat carried by the cooling medium is usually directly dissipated to the environment through the radiator. Changes in the physicochemical properties of fuel after absorbing heat and heating up, such as reduced dynamic viscosity and improved atomization performance, are not utilized, resulting in ineffective heat dissipation.

[0020] Example 1: This embodiment provides an oil-cooled fuel pump motor, such as Figure 1 As shown, the oil-cooled fuel pump motor uses the motor housing 1 as its core load-bearing structure. The composite oil pump 8 is integrated into one axial end face of the motor housing 1, and the driver is integrated into the outer side of the motor housing 1. The heat dissipation area of ​​the motor stator 2 and the heat dissipation area of ​​the driver are connected in series through a through fuel cooling oil circuit, with fuel serving as both the cooling medium and the working fluid for combustion.

[0021] like Figure 2 As shown, the main body of the motor housing 1 is cylindrical, integrally formed using a metal additive manufacturing process, and a fixed base is provided at the bottom of the cylinder. Figure 3As shown, a radially spiral cooling channel 7 is formed inside the cylindrical wall of the motor housing 1. This radial spiral extension reduces oil resistance. The spiral cooling channel 7 is a rectangular cross-section, attached to the cylindrical wall of the motor housing 1, and continuously penetrates the wall thickness along the motor axial direction. One end of the spiral cooling channel 7 forms an oil inlet 31, and the other end forms an oil outlet. Both the oil inlet 31 and the oil outlet extend to the outer circumference of the motor housing 1. Pipe fitting threads are provided at both the oil inlet 31 and the oil outlet for sealing connection with external oil circuits. A bottom wall is maintained between the spiral cooling channel 7 and the inner wall of the motor housing 1. This bottom wall is part of the cylindrical wall of the motor housing 1, and its inner surface forms the assembly contact surface of the motor stator 2. The cross-sectional shape, pitch, and wall thickness of the spiral cooling channel 7 are all integrally formed with the motor housing 1 using additive manufacturing technology, requiring no additional machining.

[0022] The motor stator 2 is fixed to the inner cavity of the motor housing 1 by an interference fit. The outer circular surface of the motor stator 2 is in close contact with the inner surface of the bottom wall of the spiral cooling channel 7, so that the heat generated by the operation of the stator winding coil 3 can be conducted to the fuel in the spiral cooling channel 7 through the iron core, outer circular surface of the stator 2, and bottom wall in a shorter path. The stator winding coil 3 is fixed in the slots of the stator iron core. The motor rotor 4 is located inside the motor stator 2, coaxially fixed to the motor main shaft, and rotates around the motor axis with the motor main shaft.

[0023] An end cap 6 is fixedly installed at each of the two axial ends of the motor housing 1. The end cap 6 is fixedly connected to the end face of the motor housing 1 by multiple circumferentially distributed fastening screws. The oil inlet 31 extends through the end cap 6 and connects to the first outlet end of the compound pump 8. A fuel-resistant O-ring is provided between the end cap 6 and the end face of the motor housing 1. The O-ring is made of rubber and is embedded in the annular groove between the end cap 6 and the end face of the motor housing 1 along the circumference of the inner cavity of the motor housing 1, sealing both ends of the spiral cooling channel 7 and ensuring that fuel flows only through the oil inlet 31 and the oil outlet. Bearing seats are provided inside the end cap 6, and the motor main shaft is supported in the bearing seats of the two end caps 6 by bearings.

[0024] In some embodiments, multiple spiral cooling channels 7 are provided. These multiple spiral cooling channels 7 are evenly distributed circumferentially along the wall of the motor housing 1 and extend synchronously axially. The oil inlet ends of each spiral cooling channel 7 converge at the same oil inlet 31, and the oil outlet ends converge at the same oil outlet. All spiral cooling channels 7 are connected in parallel. While maintaining the same total flow rate, the structure of multiple spiral cooling channels 7 reduces the fuel flow velocity within a single channel, thereby reducing the overall pressure drop of the oil circuit.

[0025] Furthermore, to enhance heat dissipation in the end region of the stator winding coil 3 and protect the insulation layer of the stator winding coil 3 from fuel corrosion, the axial ends of the stator winding coil 3 are filled with thermally conductive epoxy resin. The thermally conductive epoxy resin isolates the ends of the stator winding coil 3 from the external environment, and at the same time, through its own thermal conductivity, conducts the heat generated at the ends of the stator winding coil 3 towards the stator core, and then through the bottom wall to the fuel in the spiral cooling channel 7.

[0026] Continue reading Figure 1 The mounting base plate 10 is integrally formed with the motor housing 1, extending outward from the outer side of the motor housing 1 to form a flat plate structure. A cooling oil return outlet 33 is provided on the side of the mounting base plate 10, and a driver cooling channel is formed inside the mounting base plate 10. The oil inlet end of the driver cooling channel (not shown in the figure) is connected to the oil outlet of the spiral cooling channel 7. After the oil is collected at the outlet end, it is output outward through the cooling oil return outlet 33. That is, the cooling oil return outlet 33 is connected to the second suction port of the compound pump 8, so that the cooled fuel is supplied to the engine combustion chamber through the second oil outlet of the compound pump 8 for final combustion. The driver cooling channel consists of multiple parallel channels with a rectangular cross-section inside the mounting base plate 10. Each parallel channel is evenly distributed inside the mounting base plate 10 in a parallel direction, forming a straight-through parallel multi-channel structure. The oil inlet end of each parallel channel is connected to the oil outlet of the spiral cooling channel 7, and the oil outlet ends of each parallel channel are collected and output to the second suction port of the compound pump 8 through the cooling oil return outlet 33.

[0027] like Figure 3 As shown, the power module 11 of the driver is fixed to the outer surface of the mounting base 10 via a pad 12. The pad 12 is sandwiched between the bottom surface of the power module 11 and the outer surface of the mounting base 10. The power module 11 is pressed and fixed to the outer surface of the mounting base 10 by fastening screws via the pad 12, so that the heat generated by the power module 11 is conducted to the mounting base 10 via the pad 12, and then transferred to the fuel in the driver cooling channel via the wall of the mounting base 10. For example, the pad 12 is an aluminum nitride ceramic pad. The pad 12 also isolates the electrical connection between the power module 11 and the fuel in the driver cooling channel. In the area of ​​the mounting base 10 directly below the power module 11, the spacing of the parallel channels is reduced compared to other areas, which increases the heat transfer area per unit area in the area with higher heat flux density, thereby enhancing local convection heat transfer.

[0028] like Figure 3As shown, the driver housing 13 is fixedly connected to the outer surface of the mounting base plate 10 by fastening screws, covering the power module 11 and the driver control board. A fuel-resistant sealing gasket is provided between the driver housing 13 and the mounting base plate 10 to isolate the electrical components inside the driver housing 13 from the fuel line. The driver control board and the electrical components of the power module 11 are encapsulated inside the cavity formed by the driver housing 13 and the mounting base plate 10.

[0029] like Figure 1 and Figure 2 As shown, the compound oil pump 8 is fixed to an axial end face of the motor housing 1 by fastening screws. The pump shaft of the compound oil pump 8 is driven by the motor main shaft. The first oil suction port of the compound oil pump 8 is connected to the oil supply line of the external oil tank, and the first oil outlet of the compound oil pump 8 is connected to the oil inlet 31 of the spiral cooling channel 7, forming a complete flow path for fuel from the external oil tank through the spiral cooling channel 7 to the driver cooling channel.

[0030] Furthermore, to prevent impurities carried in the fuel from clogging the spiral cooling channel 7 and the driver cooling channel, a fuel filter is connected in series in the oil line between the oil inlet 31 and the first oil outlet of the composite oil pump 8. The fuel filter housing contains a filter element, and the fuel filter housing is connected to the oil inlet line via a detachable quick-release connector, facilitating removal from the outside of the equipment and periodic replacement of the filter element.

[0031] Working principle: When the motor spindle rotates, it drives the composite oil pump 8 to continuously draw low-temperature fuel from the external oil tank, and pressurizes the fuel and forces it into the spiral cooling channel 7 inside the cylinder wall of the motor housing 1 through the oil inlet 31.

[0032] Fuel flows axially along a spiral path within the spiral cooling channel 7. During this flow, the fuel remains in continuous contact with the inner surface of the bottom wall of the spiral cooling channel 7, which is in close contact with the outer surface of the motor stator 2. The copper and iron losses generated by the operation of the stator winding coil 3 are conducted through the stator core, the outer surface of the stator, and the bottom wall to the fuel within the spiral cooling channel 7. The fuel then carries away the heat through forced convection heat transfer, thus cooling the motor stator 2.

[0033] In some embodiments, when the spiral cooling channel 7 has multiple structures, the fuel entering the oil inlet 31 is evenly distributed to each parallel spiral channel. The fuel in each channel flows synchronously and absorbs the heat distributed along the axial direction of the stator. The fuel at the outlet of each channel merges and enters the driver cooling channel.

[0034] After flowing through the spiral cooling channel 7, the fuel enters the driver cooling channel within the mounting base plate 10 through the outlet. The fuel flows directly from the inlet side to the outlet side within each parallel channel. The outer wall of the driver cooling channel is in close contact with the pad 12, and the power module 11 is fixed above the pad 12. The heat generated by the power module 11 during operation is conducted to the mounting base plate 10 via the pad 12, and then transferred to the fuel within the driver cooling channel via the wall of the mounting base plate 10. The fuel carries away the heat through forced convection heat transfer, thus cooling the driver power module 11. In the denser channel region directly below the power module 11, the heat transfer area per unit area is increased, and local convection heat transfer is enhanced, keeping the junction temperature of the power module 11 within the allowable range.

[0035] After cooling the motor stator 2 and the driver power module 11, the fuel carrying system waste heat flows out from the cooling return oil outlet 33 of the driver cooling channel and returns to the compound pump 8. The cooled fuel then supplies fuel to the engine through the second outlet of the compound pump 8, i.e., it is pressurized to the rated pressure required for engine fuel supply by the compound pump 8, and then delivered to the engine combustion chamber for combustion. During the cooling process, the fuel absorbs heat and heats up, its dynamic viscosity decreases, its fluidity improves, and its atomization performance is enhanced. After the heated fuel is supplied to the engine combustion chamber, the waste heat absorbed during the cooling process becomes a component of the fuel enthalpy and participates in the engine's thermodynamic cycle.

[0036] Technical effects of this embodiment: Since the spiral cooling channel 7 is directly opened inside the cylinder wall of the motor housing 1, and the motor housing 1 is integrally formed by metal additive manufacturing process, the cross-sectional shape, pitch and wall thickness of the spiral cooling channel 7 are formed simultaneously during the forming process. Therefore, the sealing connection link in the traditional split channel structure is eliminated, reducing the leakage risk caused by split connection. At the same time, the bottom wall can efficiently conduct stator heat to fuel in the spiral cooling channel 7, improving the heat exchange efficiency of the heat dissipation area of ​​the motor stator 2.

[0037] Since the mounting base plate 10 is integrally formed with the motor housing 1, and the driver cooling channel inside the mounting base plate 10 is connected in series with the oil outlet of the spiral cooling channel 7, the heat dissipation area of ​​the motor stator 2 and the heat dissipation area of ​​the driver share the same fuel cooling oil circuit. There is no need to configure separate circulating pumps and liquid storage devices for motor cooling and driver cooling, the number of fluid circuit components included in the system is reduced, the overall structure is more compact, and it is beneficial for deployment in applications where size and weight are limited.

[0038] Since the pad 12 is sandwiched between the power module 11 and the mounting base plate 10, the thermal conductivity of the pad 12 ensures the thermal conductivity efficiency from the power module 11 to the driver cooling channel. At the same time, the electrical insulation performance of the pad 12 isolates the electrical connection between the power module 11 and the fuel in the driver cooling channel. This allows the requirements of driver heat dissipation efficiency and electrical safety to be met simultaneously in the same structural layer, without the need for an additional insulating protective layer, thus avoiding the problem of increased thermal resistance due to the superposition of an additional insulating layer.

[0039] Since the fuel, after completing its cooling task, is directly delivered to the engine combustion chamber for combustion, the waste heat generated by the motor stator 2 and the driver power module 11 enters the combustion chamber with the fuel and is converted into a component of the fuel enthalpy. Therefore, the waste heat is not dissipated to the environment through the radiator, but is converted into preheating heat supplied to the engine, thus avoiding the ineffective dissipation of waste heat to the environment in traditional heat dissipation methods.

[0040] Example 2: In applications such as vehicle operation in cold regions, the oil-cooled fuel pump motor servo system must withstand extreme conditions of low speed and low temperature. The motor outputs high torque at extremely low speeds (5% to 15% of rated speed), the stator windings carry near-peak currents, and the rotor permanent magnets experience significant eddy current losses due to high-order harmonics in the stator magnetic field. The driver power module 11 also experiences high conduction losses. Simultaneously, the ambient temperature is... to Within this range, the kinematic viscosity of fuel increases dramatically to tens of times its normal temperature value.

[0041] Under this combined operating condition, in the method of radially ejecting fuel from the inner bore of the main shaft by centrifugal force, the centrifugal force is proportional to the square of the rotational speed. (in For centrifugal force, For fuel quality, Main axis angular velocity, (The radius of rotation is not specified). At low speeds, the centrifugal force is severely insufficient, causing the rotor cooling circuit to fail. If the actuator cooling uses a jet orifice plate 22 micro-hole array, the driving pressure difference required for high-viscosity fuel to flow through the micro-holes is proportional to the viscosity. At low speeds, the outlet pressure of the composite oil pump 8 is far from sufficient to overcome the flow resistance of high-viscosity fuel through the micro-hole array, causing the actuator cooling circuit to fail simultaneously. Both rotor cooling and actuator cooling, two critical components, fail under the combined conditions of low speed and low temperature. Furthermore, the total fuel supply capacity of the composite oil pump 8 is extremely limited under the dual constraints of low speed and high viscosity, and there is a lack of effective flow distribution and resistance matching methods between the two cooling circuits.

[0042] Based on the aforementioned embodiments, this embodiment further adds a spiral blade pumping component inside the hollow main shaft 5, improves the oil slinger hole structure of the rotor cooling circuit, improves the jet orifice plate 22 structure of the driver cooling circuit, and adds a flow divider valve 28 at the parallel flow divider node of the rotor cooling circuit and the driver cooling circuit, together forming a spiral pumping and progressive jet synergistic cooling structure. The structure and connection relationship of components such as the motor housing 1, spiral cooling channel 7, end cover 6, mounting base plate 10, pad 12, driver housing 13, and composite oil pump 8 are the same as in the aforementioned embodiments.

[0043] Continue reading Figure 3 In this embodiment, the motor spindle is a hollow structure, namely the hollow spindle 5. The hollow spindle 5 has a cylindrical inner hole that runs through the axis to allow fuel to flow and to accommodate the helical blade pumping component.

[0044] like Figure 3 As shown, a central support rod 15 is axially arranged in the inner hole of the hollow main shaft 5, extending along the axis of the main shaft and coaxial with the hollow main shaft 5. A gear ring is provided on the side of the hollow main shaft 5 near the composite oil pump 8, and the gear ring meshes with a gear 34. The pump shaft of the composite oil pump 8 is connected to the gear shaft of the gear 34 via a coupling 9. The end of the central support rod 15 near the composite oil pump 8 protrudes from the end of the hollow main shaft 5 and is inserted into a fixed seat 17 on the end cover 6 via a spline connection. The spline connection locks the central support rod 15 and the fixed seat 17 circumferentially, preventing the central support rod 15 from rotating with the hollow main shaft 5. The fixed seat 17 has a stepped surface, and the spline end face of the central support rod 15 abuts against the stepped surface of the fixed seat 17, providing axial positioning constraint. The end of the central support rod 15 away from the composite oil pump 8 is supported on the inner wall of the hollow spindle 5 by a sliding bearing. The sliding bearing allows the hollow spindle 5 to rotate freely relative to the central support rod 15, while providing radial support to the far end of the central support rod 15.

[0045] Continue reading Figure 3 A helical blade 16 is fixedly mounted on the portion of the central support rod 15 located inside the hollow spindle 5. The inner edge of the helical blade 16 is fixedly connected to the outer surface of the central support rod 15, and a radial clearance is maintained between the outer edge of the helical blade 16 and the inner wall of the hollow spindle 5. The helical blade 16 is spirally distributed along the axial direction of the inner hole of the hollow spindle 5, surrounding the central support rod 15 and being surrounded by the inner wall of the hollow spindle 5. Since the central support rod 15 is circumferentially locked to the fixed seat 17 via a spline connection, the helical blade 16 and the central support rod 15 remain stationary during motor operation, while the hollow spindle 5 rotates relative to the stationary helical blade 16.

[0046] The pitch of the helical blade 16 gradually decreases axially from the oil inlet end to the distal end, forming a variable pitch helical surface, such as... Figure 3 As shown, the pitch of the helical blade 16 gradually decreases from left to right. When the hollow main shaft 5 rotates, the inner wall of the hollow main shaft 5 rotates relative to the stationary helical blade 16. The fuel between the inner wall of the hollow main shaft 5 and the surface of the helical blade 16 is subjected to shearing action. The variable pitch helical surface applies an axial thrust component to the fuel, forcibly conveying the fuel axially from the inlet end to the distal end, and gradually increasing the pressure along the axial direction to each oil slinger group 18. This pumping driving force comes from the rotational torque of the hollow main shaft 5 rather than centrifugal force, and remains effective at low speeds.

[0047] Furthermore, to reduce the pumping resistance of the helical blade 16 under low temperature and high viscosity conditions, shallow teeth are machined along the axial direction on the blade surface of the helical blade 16, with the tooth peaks forming an acute angle with the normal direction of the helical surface. When high-viscosity fuel flows on the surface of the shallow teeth, the shallow teeth exert microscopic shear disturbance on the fuel, disrupting the velocity boundary layer of the high-viscosity fuel adhering to the wall, reducing the thickness of the wall adhesion layer, thereby reducing the shear driving force required for pumping, allowing the helical blade 16 to maintain basic axial pumping function under low temperature and high viscosity conditions.

[0048] like Figure 3 and Figure 4 As shown, multiple sets of oil-throwing hole groups 18 are distributed axially on the wall surface of the hollow main shaft 5. Each set of oil-throwing hole groups 18 includes a large-diameter oil-throwing hole 19 and multiple small-diameter oil-throwing holes 20. The diameter of the large-diameter oil-throwing hole 19 is three to five times the diameter of the small-diameter oil-throwing hole 20. The large-diameter oil-throwing holes 19 and the small-diameter oil-throwing holes 20 are distributed circumferentially along the hollow main shaft 5 within the same group, and the groups are arranged at intervals along the axial direction. Both the large-diameter oil-throwing holes 19 and the small-diameter oil-throwing holes 20 radially penetrate the wall surface of the hollow main shaft 5, connecting the space enclosed by the inner hole of the hollow main shaft 5 and the inner circular surface of the rotor core.

[0049] A temperature-controlled sealing element 21 is installed inside the large-diameter oil slinger 19. The temperature-controlled sealing element 21 adopts a wax-type thermal expansion plunger structure. The temperature-controlled sealing element 21 includes a wax cavity and a plunger. The wax cavity is fixedly embedded in the radial outer end of the large-diameter oil slinger 19. The wax cavity contains a phase change wax. The open end of the wax cavity faces the inner circular surface of the rotor core and is in direct contact with the fuel at the inner circular surface of the rotor core to sense the temperature. One end of the plunger is inserted into the wax cavity and contacts the phase change wax. The other end extends inward along the radial direction of the large-diameter oil slinger 19. The plunger and the wall of the large-diameter oil slinger 19 form a sliding pair. At low temperature, the phase change wax is in a solid state and its volume shrinks. Under the action of the contraction force of the phase change wax, the plunger retracts into the direction of the wax cavity, and the large-diameter oil slinger 19 is in a fully open state. At this point, under the limited axial pumping pressure provided by the spiral blades 16, the high-viscosity fuel flows out from the large-diameter oil slinger 19, whose flow resistance is much lower than that of the small-diameter oil slinger 20, and contacts the inner surface of the rotor core, providing basic heat dissipation for the rotor. When the fuel temperature near the inner surface of the rotor core rises to the phase change temperature of the phase change wax, the phase change wax undergoes a solid-to-liquid phase change expansion. The volume expansion pushes the plunger to extend radially inward to block the large-diameter oil slinger 19, and the fuel is only ejected from the small-diameter oil slinger 20, forming a high-speed jet that impacts the inner surface of the rotor core, switching to jet impact cooling mode. The temperature control sealing element 21 is a passive thermal response element and does not require external power supply.

[0050] like Figure 5 As shown, the mounting base plate 10 has a jet chamber inside, located below the power module 11. A jet orifice plate 22 is fixed inside the jet chamber, dividing it into an oil inlet side space and an impact side space. Figure 5 As shown, the oil inlet side space is located below the impact side space and is connected to the driver cooling channel. The impact side space is located between the jet orifice plate 22 and the impact receiving surface of the power module 11. The jet orifice plate 22 has a micro-hole array distributed on it. Fuel flows from the oil inlet side space through the micro-hole array to form a high-speed jet that impacts the impact receiving surface of the power module 11.

[0051] A bypass orifice 23 is provided at the edge of the jet orifice plate 22. The diameter of the bypass orifice 23 is five to eight times that of the micro-orifice array. A wax-type thermal expansion element 24 and a temperature-controlled valve core 25 are installed inside the bypass orifice 23. The wax-type thermal expansion element 24 includes a wax chamber shell and a temperature sensor. The wax chamber shell is fixedly embedded in one end of the impact side space of the bypass orifice 23. The temperature sensor extends from the wax chamber shell into the impact side space and directly contacts the fuel in the impact side space to sense the temperature. The temperature-controlled valve core 25 is a columnar valve core. One end of the temperature-controlled valve core 25 abuts against the power output end of the wax-type thermal expansion element 24. Driven by the expansion of the wax in the wax-type thermal expansion element 24, it makes linear expansion and contraction along the orifice axis within the bypass orifice 23. The temperature-controlled valve core 25 and the orifice wall of the bypass orifice 23 form a sliding pair. The other end of the temperature control valve core 25 is connected to the return spring 26. The other end of the return spring 26 abuts against the stepped surface of one end of the oil inlet space of the bypass large hole 23 and is compressed and installed along the axial direction of the bypass large hole 23.

[0052] At low temperatures, the wax in the wax-type thermal expansion element 24 is in a solid, contracted state. The return spring 26 drives the temperature-controlled valve core 25 to retract towards the impact side space, and the bypass orifice 23 is fully open. High-viscosity fuel bypasses the micropore array and enters the impact side space through the bypass orifice 23 in an immersed flow manner, contacting the impact receiving surface of the power module 11 and providing basic heat dissipation for the power module 11 under low-temperature conditions. When the fuel temperature in the impact side space rises to the phase change temperature of the wax in the wax-type thermal expansion element 24, the wax in the wax-type thermal expansion element 24 expands, pushing the temperature-controlled valve core 25 to extend axially along the bypass orifice 23 towards the oil inlet space to block the bypass orifice 23. All the fuel then forms a high-speed jet through the micropore array to impact the impact receiving surface of the power module 11, switching to jet impact cooling mode. The wax-type thermal expansion element 24 is a passive thermal response element and does not require external power supply.

[0053] Furthermore, to improve the temperature uniformity of the impact receiving surface under low-temperature immersion flow conditions, a grid-shaped guide rib 27 is provided at the impact side space outlet of the bypass orifice 23. The grid-shaped guide rib 27 is fixed to the edge of the orifice of the bypass orifice 23, and divides the fuel entering the impact side space through the bypass orifice 23 into multiple fine streams, avoiding large streams of fuel from rushing in and causing uneven local impact.

[0054] A flow divider valve 28 is installed at the parallel branch node of the rotor cooling circuit and the driver cooling circuit. The flow divider valve 28 is installed on the external oil line and is located at the parallel branch node of the spiral cooling channel 7 oil outlet and the rotor cooling circuit and the driver cooling circuit.

[0055] like Figure 6As shown, the valve body of the diverter valve 28 has an axially oriented valve hole, in which a spool valve 29 is installed. The spool valve 29 slides linearly back and forth within the valve hole, forming a sliding pair with the valve hole wall. The valve body sidewall has a rotor oil supply port connected to the rotor cooling circuit and a driver oil supply port connected to the driver cooling circuit. When the spool valve 29 slides axially, its shoulder changes the effective opening area of ​​the rotor oil supply port and the driver oil supply port, thereby adjusting the flow distribution ratio between the two circuits. One end of the spool valve 29 abuts against a shape memory spring 30, and the other end of the shape memory spring 30 is fixed to the inner wall of the valve body end cover. The shape memory spring 30 is thermally coupled to the mounting base plate 10 through a heat-conducting element, sensing the temperature of the driver power module 11. The other end of the spool valve 29 faces the back pressure feedback hole of the rotor cooling circuit, which is located on the valve body wall of the diverter valve 28, guiding the return oil back pressure of the rotor cooling circuit to the end face of the spool valve 29. The valve core 29 abuts against the resistance spring 35 at one end, and the other end of the resistance spring 35 is fixed to the inner wall of the end cap at the other end of the valve body, compressed and installed along the sliding direction of the valve core 29. The valve body is closed at both ends by end caps, which are fixed to both ends of the valve body by threaded connections, thus axially limiting the valve core 29.

[0056] The back pressure of the rotor cooling circuit acts on the end face of the slide valve core 29 through the back pressure feedback hole, forming a mechanical response that counterbalances the thrust of the shape memory spring 30. During the low-temperature start-up phase, the temperature of the driver power module 11 is low, and the shape memory spring 30 is in a low-temperature contracted state, reducing the thrust on the slide valve core 29. Under the action of the spring 35, the slide valve core 29 deviates to a position that increases the effective opening area of ​​the rotor oil supply port, preferentially allocating the limited pumping flow provided by the composite oil pump 8 to the rotor cooling circuit, matching the heat load distribution characteristics where rotor losses account for the main proportion of total losses under low-speed, high-current operating conditions. As the system temperature rises, the shape memory spring 30 gradually extends, applying a continuously increasing thrust to the slide valve core 29, pushing the slide valve core 29 to gradually increase the effective opening area of ​​the driver oil supply port, while simultaneously decreasing the effective opening area of ​​the rotor oil supply port, achieving continuous adaptive adjustment of the ratio of the two cooling flow paths.

[0057] Working principle: In the low-speed and low-temperature combined working condition stage, the combined oil pump 8 is driven by the motor spindle at low speed to draw low-temperature and high-viscosity fuel from the external oil tank. The fuel is then pressed into the spiral cooling channel 7 through the oil inlet 31 to perform basic cooling on the motor stator 2, and then flows out through the oil outlet to the parallel diversion node before the diversion valve 28.

[0058] Meanwhile, the hollow main shaft 5 rotates at a low speed. The inner wall of the hollow main shaft 5 undergoes shearing motion relative to the stationary helical blades 16. The variable pitch helical surface applies an axial thrust component to the fuel, forcibly pumping the fuel at the oil inlet of the hollow main shaft 5 axially to each set of oil slinger holes 18. At low temperatures, the phase change wax of the temperature control sealing element 21 in the large-diameter oil slinger holes 19 is in a solid state, the plunger retracts, and the large-diameter oil slinger holes 19 are fully open. Under limited pumping pressure, the fuel flows out from the large-diameter oil slinger holes 19, contacting the inner surface of the rotor core and providing basic heat dissipation for the rotor.

[0059] During the low-temperature stage, the flow divider valve 28 biases the spool valve core 29 of the shape memory spring 30 in a contracted state to a position that prioritizes supplying the rotor cooling circuit, allocating a larger proportion of the limited pumped flow to the rotor cooling circuit. The driver cooling circuit receives a smaller proportion of the flow, and fuel flows through the bypass orifice 23 in an immersed manner through the impact side space, providing basic heat dissipation to the power module 11. The grid-like guide ribs 27 divide the fuel entering the bypass orifice 23, improving the temperature uniformity of the impact receiving surface.

[0060] As the motor continues to run, the system enters the temperature rise and switching stage. The fuel temperature near the inner circular surface of the rotor core increases, and the phase change wax of the temperature control sealing element 21 at each group of large-diameter oil slingers 19 undergoes phase change expansion, pushing the plunger to extend and gradually seal the large-diameter oil slingers 19. The fuel cooling on the rotor side gradually switches to a high-speed jet impact mode that is only sprayed out through the small-diameter oil slingers 20.

[0061] After the fuel temperature on the driver side rises, the wax in the wax thermal expansion element 24 at the bypass large hole 23 on the edge of the jet orifice plate 22 expands, pushing the temperature control valve core 25 to block the bypass large hole 23. All the fuel then passes through the micro-hole array to form a jet impact, and the driver side switches to the jet impact cooling mode.

[0062] Simultaneously, the shape memory spring 30 elongates as the temperature of the power module 11 rises, continuously pushing the slide valve core 29 to adjust the flow ratio, gradually increasing the effective opening area of ​​the driver's oil supply port, matching the characteristic of the driver's thermal load ratio increasing during the high-temperature stage.

[0063] After the system temperature stabilizes to the normal operating temperature range, it enters the normal operation phase. All large-diameter oil slinger holes 19 on the rotor side are sealed, and fuel is only ejected at high speed through the small-diameter oil slinger holes 20 to provide jet impact cooling to the inner surface of the rotor core. All bypass holes 23 on the driver side are sealed, and all fuel is ejected at high speed through a micro-hole array to impact the receiving surface of the power module 11. The flow divider valve 28 adaptively maintains the two-way flow distribution ratio according to the dynamic balance between the power module 11 temperature and the rotor back pressure. After cooling the rotor and driver, the fuel carrying waste heat is combined and transported to the engine combustion chamber via the compound pump 8 to participate in combustion, where the waste heat is converted into fuel enthalpy, a process similar to the aforementioned embodiment.

[0064] Technical effects of this embodiment: Since the helical blade 16 is fixed to the central support rod 15 and remains stationary, the axial pumping force is provided by the shearing action of the fuel between the inner wall of the hollow main shaft 5 and the surface of the stationary helical blade 16 when the hollow main shaft 5 rotates. This force comes from the rotational torque rather than the centrifugal force. Therefore, effective axial pumping pressure can still be generated at extremely low speeds of 5% to 15% of the rated speed, so that the rotor cooling circuit can maintain basic fuel supply capacity under low speed conditions.

[0065] Because the surface of the helical blade 16 is machined with shallow teeth, when high-viscosity fuel flows, the shallow teeth destroy the velocity boundary layer of the wall adhesion layer, thus reducing the shear driving force requirement. This allows the helical blade 16 to maintain basic axial pumping function under low temperature and high viscosity conditions, avoiding a sharp drop in pumping efficiency caused by high viscosity.

[0066] Because the rotor side employs an oil slinger assembly 18, the large-diameter oil slinger 19 is fully open at low temperatures. The flow resistance of the large-diameter oil slinger 19 is much lower than that of the small-diameter oil slinger 20. Therefore, high-viscosity fuel can flow out from the large-diameter oil slinger 19 and contact the inner surface of the rotor core under limited pumping pressure. When the temperature rises, the temperature-controlled sealing element 21 automatically seals the large-diameter oil slinger 19 and switches to high-speed jet from the small-diameter oil slinger 20. No external control signal intervention is required throughout the process, achieving adaptive thermal response switching of the cooling mode.

[0067] Because the bypass orifice 23 on the driver side is fully open at low temperatures, high-viscosity fuel bypasses the micropore array and directly enters the impact side space via immersion flow. Therefore, the driver cooling circuit can still maintain basic heat dissipation function under low-temperature, high-viscosity conditions. The temperature-controlled on / off valve core 25 automatically closes the bypass path after the temperature rises, switching to the micropore array jet impact cooling mode without external control. The grid-like guide ribs 27 divide the fuel into multiple fine streams during the low-temperature immersion flow stage, improving the temperature uniformity of the impact receiving surface.

[0068] Because the diverter valve 28 prioritizes the allocation of limited pumping flow to the rotor cooling circuit during the low-temperature start-up phase, it matches the high rotor loss ratio under low-speed, high-current operating conditions. This avoids the problem of limited pumping capacity being evenly distributed when both cooling circuits are in a state of extremely high flow resistance, resulting in each circuit failing to meet the minimum cooling flow requirement. As the system temperature rises, the shape memory spring 30 extends to push the slide valve core 29 to continuously adjust the flow distribution ratio. This coordinates with the opening and closing actions of the rotor-side temperature control blocking element 21 and the actuator-side temperature control on / off valve core 25, achieving synchronous recovery and gradual mode switching of the two cooling links under the combined extreme condition of simultaneous failure of rotor cooling and actuator cooling.

[0069] The embodiments of the present invention have been described above. However, the embodiments are not limited to the specific implementation methods described above. The specific implementation methods described above are merely illustrative and not restrictive. Those skilled in the art can make more equivalent embodiments under the guidance of the present embodiments, and all of them are within the protection scope of the present embodiments.

Claims

1. An oil-cooled fuel pump motor, characterized in that, include: The motor housing has a spiral cooling channel extending radially inside its cylindrical wall, with one end of the spiral cooling channel forming an oil inlet. The motor stator and motor rotor are fixed in the inner cavity of the motor housing. The outer circular surface of the motor stator is in close contact with the inner side of the bottom wall of the spiral cooling channel. The stator winding coil is wound on the surface of the motor stator. The motor rotor is located inside the motor stator and is coaxially fixed to the motor main shaft. It rotates around the motor axis with the motor main shaft. The mounting substrate has a cooling oil return outlet on its side and a driver cooling channel inside the mounting substrate. The oil inlet of the driver cooling channel is connected to the oil outlet of the spiral cooling channel, and the oil outlet of the driver cooling channel is connected to the cooling oil return outlet. The power module is mounted on the outer surface of the mounting substrate. The composite oil pump is fixed to one axial end face of the motor housing. The pump shaft of the composite oil pump is connected to the main shaft of the motor. The first oil inlet of the composite oil pump is connected to the external oil tank. The first oil outlet of the composite oil pump is connected to the oil inlet of the spiral cooling channel. The second oil inlet of the composite oil pump is connected to the cooling return oil outlet. The spiral cooling channel has a bottom wall between it and the inner wall of the motor housing. The inner side of the bottom wall forms the assembly contact surface of the motor stator. The heat generated by the stator winding coil is conducted to the fuel in the spiral cooling channel through the motor stator and the bottom wall. The heat generated by the power module is conducted to the fuel in the driver cooling channel through the wall of the mounting base plate. After cooling, the fuel is delivered to the second inlet of the compound pump through the cooling return oil outlet.

2. The oil-cooled fuel pump motor according to claim 1, characterized in that, The spiral cooling channels are provided in multiple ways. These spiral cooling channels are evenly distributed along the circumference of the motor housing cylinder wall and extend synchronously along the axial direction. The oil inlet ends of each spiral cooling channel converge at the same oil inlet, and the oil outlet ends converge at the same outlet. All spiral cooling channels are connected in parallel.

3. The oil-cooled fuel pump motor according to claim 1, characterized in that, The driver cooling channel consists of multiple parallel channels formed inside the mounting substrate. The oil inlet of each parallel channel is connected to the outlet of the spiral cooling channel. The oil outlets of each parallel channel converge and are output to the outside through the cooling return oil outlet. In the mounting substrate area directly below the power module, the spacing between the parallel channels is reduced compared to other areas.

4. The oil-cooled fuel pump motor according to claim 1, characterized in that, The axial ends of the stator winding coil are filled with thermally conductive epoxy resin. The thermally conductive epoxy resin is used to isolate the ends of the stator winding coil from the external environment and to conduct the heat generated at the ends of the stator winding coil towards the iron core of the motor stator.

5. The oil-cooled fuel pump motor according to claim 1, characterized in that, The driver housing is fixedly mounted on the outer surface of the mounting base plate, and the driver housing covers the power module.

6. The oil-cooled fuel pump motor according to claim 1, characterized in that, The motor spindle is a hollow spindle with an axially penetrating cylindrical inner hole. A gear ring is located on the side of the hollow spindle near the composite oil pump. This gear ring meshes with a gear, and the pump shaft of the composite oil pump is connected to the gear shaft via a coupling. A central support rod is axially positioned within the inner hole of the hollow spindle, coaxial with the hollow spindle. One end of the central support rod passes through the hollow spindle and inserts into a fixed seat on the end cover, locking it circumferentially. The other end of the central support rod is located inside the hollow spindle. The central support rod is supported by a sliding bearing on the inner wall of the hollow main shaft. A helical blade is fixedly installed on the portion of the central support rod located inside the hollow main shaft. The inner edge of the helical blade is fixedly connected to the outer surface of the central support rod, and a radial clearance is maintained between the outer edge of the helical blade and the inner wall of the hollow main shaft. The pitch of the helical blade gradually decreases axially from the oil inlet end to the distal end, forming a variable pitch helical surface. When the hollow main shaft rotates, the inner wall of the hollow main shaft rotates relative to the stationary helical blade. The variable pitch helical surface applies an axial thrust component to the fuel, transporting the fuel axially.

7. The oil-cooled fuel pump motor according to claim 6, characterized in that, Multiple sets of oil slinger holes are distributed axially on the wall surface of the hollow spindle. Each set of oil slinger holes includes a large-diameter oil slinger hole and multiple small-diameter oil slinger holes. The diameter of the large-diameter oil slinger hole is larger than that of the small-diameter oil slinger holes. Both the large-diameter and small-diameter oil slinger holes radially penetrate the wall surface of the hollow spindle. A temperature-controlled sealing element is installed inside the large-diameter oil slinger hole. The temperature-controlled sealing element adopts a wax-type thermal expansion plunger structure, including a wax cavity and a plunger. The wax cavity is fixedly embedded in the radial outer end of the large-diameter oil slinger hole. The plunger contains a phase change wax body. One end of the plunger is inserted into the wax cavity and contacts the phase change wax body, while the other end extends inward along the radial direction of the large-diameter oil slinger hole. The plunger and the wall of the large-diameter oil slinger hole form a sliding pair. At low temperatures, the phase change wax body is in a solid state, the plunger retracts into the wax cavity, and the large-diameter oil slinger hole is fully open. When the fuel temperature rises to the phase change temperature of the phase change wax body, the phase change wax body expands and pushes the plunger to extend inward along the radial direction to block the large-diameter oil slinger hole, and the fuel is only sprayed out from the small-diameter oil slinger hole.

8. The oil-cooled fuel pump motor according to claim 6, characterized in that, The mounting base plate contains a jet chamber located below the power module. A jet orifice plate is fixed within the jet chamber, dividing it into an oil inlet space and an impact space. The oil inlet space communicates with the driver cooling channel. A micro-pore array is distributed on the jet orifice plate. A bypass orifice is formed at the edge of the jet orifice plate, with a diameter larger than that of the micro-pore array. A wax-type thermal expansion element and a temperature-controlled on / off valve core are installed within the bypass orifice. The wax chamber shell of the wax-type thermal expansion element is fixedly embedded in the bypass orifice. At one end of the impact side space of the bypass orifice, one end of the temperature-controlled valve core abuts against the power output end of the wax-type thermal expansion element, and the other end of the temperature-controlled valve core is connected to a spring. The other end of the return spring abuts against the stepped surface at one end of the oil inlet side space of the bypass orifice. In the low temperature state, the return spring drives the temperature-controlled valve core to retract towards the impact side space, and the bypass orifice is in the fully open state. When the fuel temperature rises to the wax phase change temperature of the wax-type thermal expansion element, the wax expands and pushes the temperature-controlled valve core to extend towards the oil inlet side space to block the bypass orifice.

9. The oil-cooled fuel pump motor according to claim 8, characterized in that, A grid-shaped guide rib is provided at the outlet of the impact side space of the bypass orifice. The grid-shaped guide rib is fixed to the edge of the orifice of the bypass orifice and splits the fuel entering the impact side space through the bypass orifice into multiple fine streams.

10. The oil-cooled fuel pump motor according to claim 8, characterized in that, A flow divider valve is installed at the parallel flow divider node of the rotor cooling circuit and the driver cooling circuit. The valve body of the flow divider valve has a valve hole along the axial direction. A slidable valve core is installed in the valve hole. The side wall of the valve body has a rotor oil supply port communicating with the rotor cooling circuit and a driver oil supply port communicating with the driver cooling circuit. When the slid valve core slides along the axial direction, the shoulder of the slid valve core changes the effective opening area of ​​the rotor oil supply port and the driver oil supply port. One end of the slid valve core abuts against a shape memory spring, and the other end of the shape memory spring is fixed to the inner wall of the valve body end cover. The shape memory spring is thermally coupled to the mounting base through a heat-conducting component. The other end of the slid valve core faces the back pressure feedback hole of the rotor cooling circuit. The slid valve core at this end also abuts against a resistance spring. The other end of the resistance spring is fixed to the inner wall of the end cover at the other end of the valve body. At low temperature, the shape memory spring is in a contracted state. Under the action of the resistance spring, the slid valve core is biased to the position that increases the effective opening area of ​​the rotor oil supply port. As the system temperature rises, the shape memory spring extends and pushes the slid valve core to gradually increase the effective opening area of ​​the driver oil supply port and simultaneously decrease the effective opening area of ​​the rotor oil supply port.

Images