Electronic Oil Pump

Abstract

To provide an electronic oil pump with a pump casing.SOLUTION: The electronic oil pump includes a fixed shaft 4 provided in a pump casing 1, an internal gear 3 eccentric with the fixed shaft and turnably connected thereto, an external gear 2 coaxially connected to the fixed shaft, turnably connected into a pump casing, and located on the outer periphery of the internal gear for engaging with the internal gear, a motor rotor 8 connected to the outer periphery of the external gear in a fixed manner, and a motor stator 93 located on the outer periphery of the rotor and connected to the pump casing in a fixed manner. In a plane passing through the axial center of the fixed shaft, projection regions of the motor stator, the motor rotor, the external gear, the internal gear, and the fixed shaft overlap with one another at least in part.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present application relates to the technical field of electronic oil pumps for new energy automobiles, and particularly to electronic oil pumps with low resistance and high stability. [Background technology]

[0002] With the rapid development of automotive electronics and new energy vehicles, the integrated and highly precisely designed electronic oil pump has been widely applied due to its features such as high efficiency, energy saving and flexible control.

[0003] Currently, electronic oil pumps are mainly composed of three parts: a rotor pump, a motor, and a controller. The controller controls the operation of the motor, which in turn drives the rotation of the rotor pump, thereby realizing the operation of the electronic oil pump.

[0004] However, conventional electronic oil pumps have drawbacks such as complicated structure, large volume, high resistance, and low stability, so there is still room for improvement. Summary of the Invention

[0005] The present application aims to provide an electronic oil pump with the advantages of compact structure, small size, low resistance, good stability and high working efficiency.

[0006] This application is a fixed shaft provided within the pump casing; an internal gear eccentrically rotatably connected to the fixed shaft; an external gear that is coaxially connected to the fixed shaft, rotatably connected within the pump casing, and positioned on the outer periphery of the internal gear and meshes with the internal gear; a motor rotor fixedly connected to the outer periphery of the external gear; a motor stator located on the outer periphery of the rotor and fixedly connected to the pump casing, An electronic oil pump is provided that includes a pump casing in which projected areas of the motor stator, the motor rotor, the external gear, the internal gear, and the fixed shaft at least partially overlap on a plane passing through the axis of the fixed shaft.

[0007] The above technical solution provides an external gear inside the motor rotor, which is integrated with the motor rotor. This design has the following advantages: First, it reduces the height of the electronic oil pump, significantly reducing the system volume and weight, and significantly reducing system material and production costs. Second, the height of the oil pump is reduced, shortening the path of pressurized cooling oil and effectively reducing friction in the rotor pump chamber, which is beneficial to improving system efficiency. Third, it simplifies the structure, reduces accumulated installation errors, improves the coaxiality of the motor rotor, motor stator, and external gear, and avoids the risk of air gap eccentricity. Fourth, it provides a more stable structure, effectively reducing the vibration noise of the pump body during operation, improving the performance of the pump body, increasing its reliability, and extending its operating life.

[0008] In some embodiments, the pump further includes a first bearing, wherein the external gear is rotatably connected to one end of the fixed shaft via the first bearing, and the other end of the fixed shaft is connected to the pump casing.

[0009] In some embodiments, the pump further includes a second bearing, one end of the fixed shaft being rotatably connected to the pump casing via the second bearing, and the other end of the fixed shaft being coaxially connected to the external gear.

[0010] Conventionally, the fixed shaft and pump casing are attached by designing a step at the bottom of the pump casing. The fixed end of the fixed shaft is threaded through the step and connected to a nut, which abuts against the end face of the step. The friction between the nut and the step creates a fixed connection between the fixed shaft and the pump casing. However, the tightness of the nut affects the axial end clearance of the pump body. During operation, the temperature inside the pump casing increases, and the difference in thermal expansion coefficients between the pump casing, fixed shaft, and nut materials (e.g., aluminum for the pump casing, stainless steel for the fixed shaft, and steel for the nut) changes the axial end clearance, further affecting the performance of the pump body. Using the above technical solution, the bearing is directly connected to the fixed shaft, reducing the aspect ratio of the electronic oil pump. The large-diameter bearing and rotating shaft have a large aspect ratio, which reduces the structural stability of the electronic oil pump. During operation, the motor and pump gears are less concentric with the rotating shaft. The installation of a small-sized bearing at the bottom of the rotating shaft provides many advantages. For example, the pump body structural system has a small aspect ratio, making the pump body structure more stable and effectively improving the concentricity of the motor, pump gear, and rotating shaft. Second, it greatly simplifies the assembly of the gear pump structure, rotating shaft, and pump body chassis, contributing to the concentricity of the pump body system structure and improving the air gap precision of the motor stator and motor rotor. This ensures that the motor always operates with a precise and uniform magnetic field distribution, making motor operation more stable and improving the utilization efficiency of the motor's magnetic field, ultimately ensuring the efficient operation of the electronic oil pump. Second, it reduces the large contact surfaces between the large-sized bearing and the gear pump's external gear and pump body chassis, reducing the cumulative assembly deviation caused by multiple contact surfaces, reducing the frictional resistance generated during rotation of the pump body structure, reducing the large centrifugal force generated during rotation of the large-sized bearing, and minimizing the impact of axial and radial end surface clearances of the pump body due to thermal expansion of different materials due to temperature, thereby improving the efficiency and stability of the electronic oil pump.

[0011] In some embodiments, the electronic oil pump further includes an eccentric calibration piece located between the fixed shaft and the internal gear, the eccentric calibration piece being a half-moon sleeve provided on the circumferential outer wall of the fixed shaft, the half-moon sleeve having an arc groove into which the fixed shaft is fitted, the half-moon sleeve being configured to eccentrically rotatably connect the internal gear to the fixed shaft. Preferably, the half-moon sleeve is fixedly connected to the pump casing.

[0012] By using the above technical solution, the eccentricity calibration piece can compensate for concentricity deviations caused by the processing and assembly of multiple components, such as the pump casing, fixed shaft, and motor, effectively ensuring the concentricity of the pump casing, fixed shaft, and motor. In this way, the external gear and the fixed shaft are rotatably connected, and the eccentric assembly is also rotatably connected to the internal gear, achieving the effects of coaxiality and eccentricity between the internal gear and the external gear. At the same time, because the fixed shaft and the pump casing are concentrically arranged, the motor rotor achieves high concentricity with the fixed shaft and the pump casing through the fixed shaft, effectively compensating for insufficient concentricity accuracy caused by tolerance accumulation during processing and assembly. The circumferential side wall portion of the fixed shaft is fitted into the arc groove, and the circumferential side wall of the fixed shaft and the circumferential outer wall of the crescent sleeve form an eccentric assembly that is rotatably connected to the internal gear, realizing the effect of coaxiality and eccentricity between the internal gear and the external gear. This effectively compensates for the lack of eccentricity of the motor's circular center and axial center caused by the accumulated tolerances during processing and assembly, and also maintains the mutual drive due to the centrifugal force of the internal gear and external gear of the rotor pump.

[0013] In some embodiments, the apparatus further comprises a bushing, wherein the internal gear is rotatably connected to the half-moon sleeve and the fixed shaft by the bushing.

[0014] By using the above technical solution, the bushing can reduce the friction between the internal gear and the fixed shaft and the half-moon sleeve, reduce the frictional resistance, and improve the rotation efficiency.

[0015] In some embodiments, the external gear and the internal gear surround a plurality of huff-and-puff oil chambers, the volumes of which first increase stepwise along the rotation direction of the external gear and then decrease stepwise, and the pump casing is provided with an oil inlet and an oil drain hole, and when the huff-and-puff oil chambers increase stepwise, the oil inlet of the huff-and-puff oil chambers corresponds to the oil inlet hole, and when the huff-and-puff oil chambers decrease stepwise, the oil drain port of the huff-and-puff oil chambers corresponds to the oil drain hole.

[0016] In some embodiments, when the huff and puff oil chamber is gradually increased, cooling oil flows into the huff and puff oil chamber through the oil supply hole, and when the huff and puff oil chamber is gradually decreased, the cooling oil in the huff and puff oil chamber is pushed out through the oil drain hole.

[0017] By adopting the above technical solution, a plurality of closed huff-and-puff oil chambers are formed around the circumferential inner wall of the inner circle of the external gear, the inner end face of the outer circle of the external gear, and the circumferential outer wall of the internal gear. When the internal gear and the external gear rotate relative to each other, the huff-and-puff oil chambers gradually increase the amount of oil in the huff-and-puff oil chambers, increasing their volume as the oil volume increases. During the oil intake, the cool oil comes into contact with the teeth of the internal gear and the external gear, and the oil absorbs heat from the teeth. The huff-and-puff oil chambers gradually decrease the amount of oil in the huff-and-puff oil chambers, decreasing their volume as the oil volume decreases. The hot oil absorbs heat during the oil intake and is discharged from the pump body through the oil drain hole, thereby achieving cooling and lubrication of the internal gear and the external gear, and cooling of the pump body, and ensuring the operating temperature and efficiency of the pump.

[0018] In some embodiments, the pump further includes a circuit control module, the circuit control module including a controller provided within the pump casing and a hub, the motor stator provided on the hub, the motor stator having a plurality of stator windings provided circumferentially thereof, the motor rotor fitted onto the circumferential outer circle of the external gear, and the circumferential outer wall of the motor rotor corresponding to the circumferential inner wall of the motor stator.

[0019] By adopting the above technical solution, the controller controls the hub to energize the multiple stator winding coils in the motor stator. After the multiple stator windings are energized, the generated magnetic field interacts with the permanent magnetic field of the rotor magnet to drive the motor rotor to rotate, and the motor rotor is integrated into the outer rotor of the gear pump. That is, the motor stator and the rotor magnet interact with each other to drive the outer gear of the rotor gear pump to rotate, and further the outer gear of the rotor gear pump drives the internal gear to rotate, thereby realizing the relative rotation of the internal gear and the external gear.

[0020] In some embodiments, the pump casing is provided with an O-seal ring on its outer periphery.

[0021] In the above technical solution, the O-type sealing ring can be deformed horizontally and axially, which is useful for sealing, reducing oil leakage, and creating high pressure, and is economical and efficient, easy to assemble, has a long service life, and is easy to maintain.

[0022] In summary, the present application can achieve at least one of the following beneficial technical effects:

[0023] 1. The electronic oil pump of this application reduces the height, volume, weight, and cost of the system, while having a simple structure, high assembly precision, high operating efficiency, and extended operating life of the product.

[0024] 2. The electronic oil pump in some embodiments of this application has a small aspect ratio, which makes the pump body structure more stable and improves the concentricity between the motor, pump gear, and rotating shaft. This design greatly reduces the difficulty of assembling the gear pump structure, rotating shaft, and pump body chassis, contributes to the concentricity of the pump body system structure, and contributes to improving the air gap precision of the motor stator and motor rotor, ensuring that the motor always operates with a precise and uniform magnetic field distribution, making the motor operation more stable and precise, and improving the utilization efficiency of the motor magnetic field, ultimately ensuring the efficient operation of the electronic oil pump.

[0025] 3. When using the second bearing, the size of the bearing is reduced, thereby reducing the contact interface area between the bearing and the external gear of the gear pump and the pump body chassis, reducing the accumulation of assembly deviation caused by multiple contact interfaces, reducing the friction resistance generated when the pump body structure rotates, and reducing the large centrifugal force generated when a large-sized bearing rotates, improving the efficiency and stability of the electronic oil pump.

[0026] 4. The second bearing is installed to fix the bottom of the rotating shaft and the pump body chassis together, and the top of the shaft is directly connected to the top cover of the external gear, ensuring precise clearances at the end face and radial direction of the pump body and avoiding the thermal expansion effect caused by the temperature coefficients of different materials during temperature changes. At the same time, the installation of the second bearing makes the structure of the electronic pump more stable, effectively reducing the vibration noise of the pump body during operation, improving the NVH performance of the pump body, improving the reliability of the pump body, and extending the operating life of the pump body. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 is a schematic diagram showing the external structure of a first embodiment of the electronic oil pump of the present application. [Figure 2] FIG. 2 is a perspective cross-sectional structural schematic diagram of a first embodiment of the electronic oil pump of the present application. [Figure 3] FIG. 3 is a schematic diagram of the internal structure of a first embodiment of the electronic oil pump of the present application. [Figure 4] FIG. 4 is a structural schematic diagram of the motor stator of the first embodiment of the electronic oil pump of the present application. [Figure 5] FIG. 5 is a structural schematic diagram of the casing of the first embodiment of the electronic oil pump of the present application. [Figure 6] FIG. 6 is a perspective cross-sectional schematic view of a second embodiment of the electronic oil pump of the present application. [Figure 7] FIG. 7 is a structural schematic diagram of the circuit control module, external gear and internal gear of the second embodiment of the electronic oil pump of the present application. [Figure 8] FIG. 8 is a schematic diagram of the structure of the motor stator, internal gear, and external gear of the electronic oil pump according to the second embodiment of the present application. [Figure 9] FIG. 9 is a structural schematic diagram of the bottom of the pump casing of the second embodiment of the electronic oil pump of the present application. [Figure 10] FIG. 10 is a structural schematic diagram of the external gear and the internal gear of the second embodiment of the electronic oil pump of the present application. [Figure 11]FIG. 11 is a structural schematic diagram of the eccentricity calibration piece of the second embodiment of the electronic oil pump of the present application. [Figure 12] FIG. 12 is a perspective cross-sectional schematic view of a third embodiment of the electronic oil pump of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0028] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in more detail below with reference to the drawings. Generally, the assemblies of the embodiments of the present invention described and shown herein can be arranged and designed in various different configurations. Based on the embodiments of the present invention, any other embodiments that a person skilled in the art can obtain without any creative work fall within the scope of protection of the present invention.

[0029] It should be noted that in the following figures, like numerals and letters represent like items, so that once an item is defined in one figure, it does not require further definition and explanation in subsequent figures.

[0030] In describing the present invention, it should be understood that unless otherwise clearly specified or limited, the terms "attached," "coupled," "connected," etc. should be broadly understood, and may refer to, for example, fixedly connected, detachably connected, integrally connected, mechanically connected, electrically connected, directly connected, indirectly connected via an intermediate medium, or internal communication between two elements. Those skilled in the art may understand the specific meanings of the above terms in the present invention according to specific circumstances.

[0031] In the description of this application, the orientations or positional relationships indicated by technical terms such as "upper," "lower," "left," and "right" are orientations or positional relationships based on those shown in the accompanying drawings, and are intended merely to facilitate and simplify the description of this application, and do not indicate or suggest that the referred-to devices or elements must have a particular orientation or be constructed and operated in a particular orientation, and therefore cannot be understood as limiting this application.

[0032] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Where no contradiction exists, the features of the following embodiments can be combined with each other. Example 1

[0033] 1 to 5, this embodiment discloses an electronic oil pump. Referring to FIG. 1, the electronic oil pump includes a pump casing 1. In some embodiments, the pump casing 1 is made of aluminum. An oil drain hole 12 is provided in the side wall of the pump casing 1, an oil supply hole 11 is provided in the bottom of the pump casing 1, and a filter 14 is provided in the bottom of the pump casing 1, located at and covering the oil supply hole 11.

[0034] 2 to 4, a fixed shaft 4, a motor, a circuit control module 9, and a gear set are mounted within a pump casing 1. The motor includes a motor rotor 8, a motor stator 93, and a stator winding 94. The motor stator 93 is fixed within the pump casing 1, the motor rotor 8 is disposed within the motor stator 93, and multiple sets of stator windings 94 are provided and wound around the motor stator 93 in a circular arrangement, and are located between the motor rotor 8 and the motor stator 93.

[0035] The gear set includes an external gear 2 integrated with and fixed to the motor rotor 8, and an internal gear 3 located within the external gear 2 and meshing with the internal teeth of the external gear 2. The internal gear 3 and a fixed shaft 4 are rotatably connected eccentrically, where eccentricity means that the rotation axes do not coincide. The external gear 2 and the fixed shaft 4 are coaxially connected and rotatably connected within the pump casing 1. The external gear 2 of the present invention is integrated with the motor rotor 8 and press-fitted as a single unit. This design, on the one hand, significantly reduces the volume and weight of the system, significantly reducing the system material and production costs, and, on the other hand, effectively reduces the rotor pump cavity friction, contributing to improving the system efficiency.

[0036] The pump casing 1 is provided with a chassis 15 for separating the controller 91 and the hub 92, separating the oil passage from the electrical control section, improving sealing, and ensuring that the controller 91 operates at an appropriate temperature. A PTC temperature sensor (not shown) is attached to the chassis 15 for detecting and feeding back the cooling oil temperature, and the PTC temperature sensor is electrically connected to the controller 91. In some embodiments, the PTC temperature sensor can achieve an oil temperature detection accuracy of 0.1°C.

[0037] The external gear is integrated into the motor rotor, and the thermal expansion coefficients of the motor stator 93 and the pump body are the same, which greatly reduces the impact of temperature on the oil pump clearance, accurately guarantees the clearance at the end face of the pump, and effectively reduces or avoids the impact of temperature on the system flow efficiency.

[0038] During operation, the circuit control module 9 controls the plurality of stator windings 94 to be energized, and the resulting magnetic field interacts with the permanent magnetic field of the magnets in the motor rotor 8 to drive the motor rotor 8 to rotate. The motor rotor 8 and the external gear 2 are fixed, i.e., the motor stator 93 and the magnets in the motor rotor 8 interact with each other to drive the external gear 2 to rotate, and the external gear 2 further drives the internal gear 3 to rotate, thereby realizing relative rotation between the internal gear 3 and the external gear 2.

[0039] In particular, the projected areas of the motor stator 93, motor rotor 8, external gear 2, internal gear 3, and fixed shaft 4 at least partially overlap on a plane passing through the axis of the fixed shaft 4. This structure reduces the axial height of the electronic oil pump, making the structure compact and small in volume.

[0040] A seal ring is further provided on the outer periphery of the pump casing 1. In some embodiments, the seal ring is an O-shaped seal ring 17 made of rubber. The O-shaped seal ring 17 is adapted for horizontal and axial deformation, and is useful for sealing, reducing oil leakage, and creating high pressure, making it economical and efficient, easy to assemble, have a long service life, and are easy to maintain.

[0041] In some embodiments, the electronic oil pump further comprises an upper cover 25 fixedly connected to the external gear 2, one end of the fixed shaft 4 is rotatably connected to the pump casing 1 via a bearing 6, and the other end of the fixed shaft 4 is coaxially fixedly connected to the external gear 2 via the upper cover 25. The internal gear 3 is eccentrically connected to the fixed shaft 4 by the pump casing 1, and the internal gear 3 is rotatably connected to the pump casing 1.

[0042] For cold starting of the high-power electronic oil pump, in this embodiment, a sensor 26, such as a magnetic inductor, is further fixedly connected to the top end of the fixed shaft 4. In other embodiments, the sensor 26 may be fixedly connected to the top cover 25, which is fixedly connected to the external gear 2.

[0043] The circuit control module 9 is provided in the pump casing 1 and includes a hub 92 located above the motor, and a controller 91 located above the hub 92. The role of the hub 92 is to collect the input and output lines of the stator winding 94, ensure regular and clear distribution of the lint, and weld the lint to the hub 92, a simple and easy process. Another role of the hub 92 is to separate the controller 91 from the motor section, so that oil flows only through the motor section, forming a cooling and lubrication circuit and preventing oil from entering the controller 91.

[0044] Above the stator assembly is a hub 92. The pins of the stator windings 94 pass through the hub 92, simplifying the design of the electrical control assembly and simplifying conventional winding construction.

[0045] The controller 91 realizes quick response and has features such as circuit reverse connection protection, signal interference prevention, oil temperature monitoring, overheating prevention, independent communication channel, motor angle position detection, motor rotation speed comparison reception and calculation, and actual rotor rotation speed comparison and adjustment.

[0046] Since the overall height of the electronic oil pump is reduced, the time required for pressurized cooling oil to flow to the stator assembly is shorter in this embodiment than in the conventional electronic oil pump, resulting in a more effective temperature reduction.

[0047] Referring to Figure 2, the operating process of the electronic oil pump: the controller 91 controls the hub 92 to energize the multiple stator windings 94 in the motor stator 93. After the multiple stator windings 94 are energized, a magnetic field is generated, driving the motor rotor 8 to rotate, and the motor stator 93 drives the external gear 2 to rotate, thereby realizing relative rotation between the external gear 2 and the internal gear 3.

[0048] As the internal gear 3 and external gear 2 rotate relative to each other, the huff-and-puff oil chamber 21 expands in stages and draws in oil through the oil supply hole 11, increasing the amount of oil in the huff-and-puff oil chamber 21 as its volume increases. During this process, the low-temperature oil comes into contact with the teeth of the internal gear 3 and external gear 2, absorbing heat from the teeth. As the huff-and-puff oil chamber 21 gradually contracts, it discharges oil through the oil drain hole 12, decreasing the amount of oil in the huff-and-puff oil chamber 21 as its volume decreases. During this process, the high-temperature oil that has absorbed the heat is discharged from the pump body through the oil drain hole 12, thereby lowering the temperature and lubricating the internal gear 3 and external gear 2, while also lowering the temperature of the pump body.

[0049] Referring to Figure 5, a pump casing bottom 13 is integrally formed with the bottom of the pump casing 1, covering the oil supply hole 11 and the oil drain hole 12. A fixing hole 131 is formed in the bottom of the pump casing 1, and the fixing hole 131 is eccentrically disposed relative to the pump casing 1. The fixed shaft 4 is disposed within the fixing hole 131, and the circumferential outer wall of the fixed shaft 4 is firmly fitted with the wall of the fixing hole 131. A sliding bearing may be provided between the internal gear 3 and the pump casing 1 to reduce rotational resistance and improve operating life. An oil suction port 132 communicating with the oil supply hole 11 and an oil discharge port 133 communicating with the oil drain hole 12 are formed in the end face of the pump casing bottom 13. A partition 134 is formed in the bottom 13 of the pump casing to separate the oil suction port 132 and the oil discharge port 133, and one side of the partition 134 is attached to one side of the internal gear 3 to improve the sealing between the oil suction port 132 and the oil discharge port 133.

[0050] In this embodiment, the eccentric fitting between the internal gear 3 and the external gear 2 is realized by the eccentric fixing hole 131 of the pump casing, and no extra accessories are required. The advantages of this design are that it simplifies the structure of the gear pump, reduces the difficulty of assembling the rotating shaft and the pump body chassis, improves the concentricity between the motor, the shell and the gear set, and is beneficial to ensuring the concentricity of the pump body system structure, contributes to improving the air gap between the motor stator and the motor rotor, ensures that the motor operation is always located in a precise and uniform magnetic field distribution, makes the motor operation more stable and precise, and improves the utilization efficiency of the motor magnetic field, ultimately ensuring the high-efficiency operation of the electronic oil pump, reduces the accumulation of assembly deviations caused by multiple contact interfaces, effectively reduces the friction resistance generated during the rotation of the pump body structure, and reduces the large centrifugal force generated during the rotation of the large-sized bearing, improves the efficiency and stability of the electronic oil pump, and is small in volume, light in weight, and low in cost. Example 2

[0051] 6 to 11, this embodiment differs from the first embodiment in the eccentric connection structure of the fixed shaft 4.

[0052] 6 to 8, in this embodiment, the external gear 2 includes an external gear inner circle 23 that meshes with the internal gear 3, and the motor rotor inner circle is fixedly fitted around the external gear outer circle. The permanent magnets of the motor rotor 8 are fixed to the outer periphery of the motor rotor outer circle 24, and an air gap 16 is provided between the permanent magnets of the motor rotor 8 and the stator winding 94. During the research and development process, it is necessary to minimize the influence of various factors on the stability of the air gap 16 distance. A motor rotor neck 22 is integrally molded on top of the motor rotor outer circle 24, and a bearing 6 is installed within the motor rotor neck 22. The ball bearing 6 supports the motor rotor 8 and ensures the rotation of the external gear 2 in the rotor pump. The ball bearing 6 is installed at the end of the rotor pump to eliminate any air gap between the motor and the rotor pump, thereby reducing the height of the electronic oil pump and significantly reducing the weight and volume of the rotor pump. In the embodiment, the ball bearing 6 is machined using the same machine tool as the pump casing 1, so that the two have very precise coaxiality and concentricity, and the eccentricity of the air gap can be precisely controlled.

[0053] 6 to 9, a fixing hole 131 is formed in the bottom of the pump casing 1 and is concentric with the pump casing 1. The fixed shaft 4 passes through the fixing hole 131, and the fixed shaft 4 and a bearing 6 are firmly fitted together. A motor rotor neck 22 fitted to the bearing 6 is integrally molded on one side of the external gear 2. The internal gear is coaxially fitted to the fixed shaft 4 and has an internal gear inner circle that abuts the eccentric assembly. The internal gear 3 is eccentrically rotatably connected to the fixed shaft 4 by an eccentric calibration piece 5, where eccentricity means that the rotation axes do not coincide. The eccentric calibration piece 5 is a semicircular sleeve provided on the circumferential outer wall of the fixed shaft 4. The semicircular sleeve has an arc groove 51 into which the fixed shaft 4 is fitted. The semicircular sleeve is provided to eccentrically rotatably connect the internal gear 3 to the fixed shaft 4. The motor rotor inner circle is axially attached to the external gear outer circle. A motor rotor neck 22 that fits into the bearing 6 is integrally molded on one side of the motor rotor outer circle 24, and a groove into which the bearing 6 fits is formed on the motor rotor neck 22 and one side of the motor rotor outer circle 24, and the circumferential outer wall of the bearing 6 is firmly fitted into the circumferential groove wall of the groove, thereby reducing operating noise.

[0054] 9 to 11, the circumferential inner wall of the external gear inner circle 23 and the circumferential outer wall of the internal gear 3 are both attached to the inner end surface of the motor rotor outer circle 24, and the area between the external gear 2 and the internal gear 3 is divided by tooth-to-tooth contact, forming a plurality of closed huff-and-puff oil chambers 21, the volume of which first increases and then decreases in stages in the rotation direction of the external gear 2, and an oil supply hole 11 is integrally formed at the bottom of the pump casing 1, and an oil drain hole 12 is integrally formed at the circumferential outer wall. When the huff-and-puff oil chamber 21 increases in stages, the oil supply port of the huff-and-puff oil chamber 21 corresponds to the oil supply hole 11, and when the huff-and-puff oil chamber 21 decreases in stages, the oil drain port of the huff-and-puff oil chamber 21 corresponds to the oil drain hole 12.

[0055] A pump casing bottom 13 is integrally formed at the bottom of the pump casing 1, covering the oil supply hole 11 and the oil drain hole 12. A fixing hole 131 is formed in the axial direction of the end face of the pump casing bottom 13, and is fixedly connected to one end of the fixed shaft 4. The fixed shaft 4 is inserted into the fixing hole 131, and the circumferential outer wall of the fixed shaft 4 is firmly fitted with the hole wall of the fixing hole 131, providing a sliding bearing between the internal gear 3 and the pump casing 1, reducing rotational resistance and improving operating life. An oil suction port 132 communicating with the oil supply hole 11 and an oil discharge port 133 communicating with the oil drain hole 12 are formed in the end face of the pump casing bottom 13. A partition 134 is formed in the bottom 13 of the pump casing to separate the oil suction port 132 and the oil discharge port 133, and one side of the partition 134 is attached to one side of the internal gear 3 to improve the sealing between the oil suction port 132 and the oil discharge port 133.

[0056] A positioning hole 52 is drilled through one side of the half-moon sleeve, and an assembly guide hole 135 corresponding to the positioning hole 52 is drilled in the pump casing bottom 13. The assembly guide hole 135 and the fixing hole 131 are arranged eccentrically, and a bushing 7 for reducing sliding friction is provided between the fixed shaft 4 and the internal gear 3. The internal gear 3 is rotatably connected to the half-moon sleeve and the fixed shaft 4 via the bushing 7.

[0057] The pump casing 1 has one hole that fits with the fixed shaft 4, which effectively reduces the complexity of the processing of the pump casing 1, improves the processing efficiency of the pump casing 1, and improves the precision of the fitting between the external gear 2 and the internal gear 3.

[0058] The implementation principle of the highly accurate designed electronic oil pump of the present application embodiment is as follows.

[0059] A fixed shaft 4 is provided inside the pump casing 1, and then an eccentric calibration piece 5 is provided on the circumferential side wall of the fixed shaft 4 to form an eccentric assembly 41. The external gear 2 and the fixed shaft 4 are rotationally connected, and at the same time, the eccentric assembly 41 is also rotationally connected to the internal gear 3, thereby achieving the effect of coaxiality and eccentricity between the internal gear 3 and the external gear 2. Example 3

[0060] 12, the difference between this embodiment and the first and second embodiments is that a bearing is provided between the external gear and the pump casing, and the fixed shaft 4 has a hollow structure. In this embodiment, a flow path for cooling oil is provided inside the fixed shaft 4. In this embodiment, the fixed shaft 4 is statically fixed, and when driven by the external gear 2, the pump internal gear 3 rotates relative to the fixed shaft 4, lubricating each other and reducing friction, which reduces wear on the rotor pump system and effectively improves the rotation stability of the rotor pump.

[0061] The algorithm by which the cooling oil of the present invention cools the stator assembly is as follows:

[0062] The motor rotor 8 drives the internal gear 3 to rotate together with the external gear 2, pressurizing the cooling oil flowing in from the oil supply hole 11. One of the pressurized cooling oils flows through the hollow passage in the fixed shaft 4 to the stator assembly, cooling the stator assembly, and the heat-exchanged cooling oil flows back to the low-pressure region.

[0063] The other pressurized cooling oil is discharged as is from the oil drain hole 12 via the high pressure region.

[0064] In this embodiment, the fixed shaft 4 is further fitted with a radial magnetic steel for detecting its position.

[0065] In the present invention, the specific process for cooling the stator assembly is as follows.

[0066] 1) First, the equipment is turned on, and at this time, the controller 91 is energized, the controller 91 converts the electricity into three-phase electricity and supplies it to the stator winding 94, the motor rotor 8 and the external gear 2 are driven to rotate by electromagnetic force, and the cooling oil flowing in from the oil supply hole 11 due to the rotation of the motor rotor 8 and the external gear 2 passes through the filter 14 and then enters the low-pressure area.

[0067] 2) The motor rotor 8 drives the internal gear 3 together with the external gear 2 to rotate around the fixed shaft 4, pressurizing the cooling oil flowing in from the oil supply hole 11, so that one side of the pressurized cooling oil flows through the fixed shaft 4 to the stator assembly, cooling the stator assembly, and the heat-exchanged cooling oil flows back to the low-pressure region, where the centrifugal force caused by the difference between the internal and external gears pressurizes the cooling oil. In this case, the PTC temperature sensor detects the current oil temperature value and feeds this temperature value back to the controller 91, which then feeds back the current oil temperature value to an external control system.

[0068] 3) The other pressurized cooling oil passes through the high pressure region and is then discharged directly from the oil drain hole 12.

[0069] The basic principles, main features and advantages of the present invention have been shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and that what is described in the above embodiments and descriptions is only for illustrating the principles of the present invention, and that there are many changes, modifications, alterations and variations to the present invention without departing from the spirit and scope of the present invention, and all of these changes, modifications, alterations and variations are included in the scope of the claims of the present invention. [Explanation of symbols]

[0070] 1. Pump casing 11. Oil filler hole 12, oil drain hole 13. Pump casing bottom 131, fixed hole 132, oil intake port 133. Oil outlet 134, partition 135, assembly guide hole 14. Filter 15. Chassis 16. Air gap 17. Seal ring 2. External gear 21. Huff and puff oil chamber 22. Motor rotor neck 23, external gear inner circle 24, motor rotor outer circle 25, upper lid 26. Sensor 3. Internal gear 4. Fixed shaft 41, eccentric assembly 5. Eccentricity calibration piece 51. Arc groove 52, positioning hole 6. Bearings 7. Bushing 8. Motor rotor 9. Circuit control module 91. Controller 92, Hub 93. Motor stator 94, stator winding

Claims

1. An electronic oil pump comprising a pump casing (1), a fixed shaft (4) provided in the pump casing (1); an internal gear (3) eccentrically rotatably connected to the fixed shaft (4); an external gear (2) coaxially connected to the fixed shaft (4), rotatably connected within the pump casing (1), positioned on the outer periphery of the internal gear (3), and meshing with the internal gear (3); a motor rotor (8) fixedly connected to the outer periphery of the external gear (2); a motor stator (93) located on the outer periphery of the motor rotor (8) and fixedly connected to the pump casing (1); a first bearing (6), In a plane passing through the axis of the fixed shaft (4), the projected areas of the motor stator (93), the motor rotor (8), the external gear (2), the internal gear (3), and the fixed shaft (4) at least partially overlap; The external gear (2) is rotatably connected to one end of the fixed shaft (4) via the first bearing (6), and the other end of the fixed shaft (4) is connected to the pump casing (1); The apparatus further includes an eccentric calibration piece (5) located between the fixed shaft (4) and the internal gear (3), the eccentric calibration piece (5) being a half-moon sleeve provided on the circumferential outer wall of the fixed shaft (4), the half-moon sleeve having an arc groove (51) into which the fixed shaft (4) is fitted, and the half-moon sleeve is provided to eccentrically connect the internal gear (3) to the fixed shaft (4) so ​​as to be rotatable. An electronic oil pump.

2. An electronic oil pump comprising a pump casing (1), a fixed shaft (4) provided in the pump casing (1); an internal gear (3) eccentrically rotatably connected to the fixed shaft (4); an external gear (2) that is coaxially connected to the fixed shaft (4), rotatably connected within the pump casing (1), and located on the outer periphery of the internal gear (3) and meshes with the internal gear (3), and an upper cover (25) is fixedly connected to the external gear (2); a motor rotor (8) fixedly connected to the outer periphery of the external gear (2); a motor stator (93) located on the outer periphery of the motor rotor (8) and fixedly connected to the pump casing (1); A second bearing (6) is provided, One end of the fixed shaft (4) is rotatably connected to the pump casing (1) via the second bearing (6), and the other end of the fixed shaft (4) is coaxially connected to the external gear (2) via an upper cover (25). The apparatus further includes an eccentric calibration piece (5) located between the fixed shaft (4) and the internal gear (3), the eccentric calibration piece (5) being a half-moon sleeve provided on the circumferential outer wall of the fixed shaft (4), the half-moon sleeve having an arc groove (51) into which the fixed shaft (4) is fitted, and the half-moon sleeve is provided to eccentrically connect the internal gear (3) to the fixed shaft (4) so ​​as to be rotatable. An electronic oil pump.

3. It further comprises a bushing (7), and the internal gear (3) is rotatably connected to the half-moon sleeve and the fixed shaft (4) by the bushing (7).

3. The electronic oil pump according to claim 1 or 2.

4. A sensor for cold starting is fixedly connected to the fixed shaft (4) or the external gear (2).

3. The electronic oil pump according to claim 1 or 2.

5. A plurality of huff-and-puff oil chambers (21) are formed around the external gear (2) and the internal gear (3), and the volume of the huff-and-puff oil chambers (21) increases and then decreases along the rotation direction of the external gear (2). The pump casing (1) is provided with an oil supply hole (11) and an oil drain hole (12). When the huff-and-puff oil chambers (21) increase in volume, the oil supply ports of the huff-and-puff oil chambers (21) correspond to the oil supply holes (11), and when the huff-and-puff oil chambers (21) decrease in volume, the oil drain ports of the huff-and-puff oil chambers (21) correspond to the oil drain holes (12).

3. The electronic oil pump according to claim 1 or 2.

6. When the huff and puff oil chamber (21) increases in size, the cooling oil flows into the huff and puff oil chamber (21) through the oil supply hole (11), and when the huff and puff oil chamber (21) decreases in size, the cooling oil in the huff and puff oil chamber (21) is pushed out through the oil drain hole (12).

6. The electronic oil pump according to claim 5.

7. The pump further includes a circuit control module (9), the circuit control module (9) including a controller (91) provided in the pump casing (1) and a hub (92), the motor stator (93) is provided on the hub (92), the motor stator (93) is provided with a plurality of stator windings (94) in its circumferential direction, the motor rotor (8) is fitted onto the circumferential outer circle of the external gear (2), and the circumferential outer wall of the motor rotor (8) corresponds to the circumferential inner wall of the motor stator (93).

3. The electronic oil pump according to claim 1 or 2.

8. An O-type seal ring is further provided on the outer periphery of the pump casing (1).

8. The electronic oil pump according to claim 7.

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