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 new energy automobile electronic oil pumps, and in particular 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 precisely designed electronic oil pump has been widely applied due to its characteristics of high efficiency, energy saving and flexible control.

[0003] Currently, an electronic oil pump is mainly composed of three parts, including a rotor pump, a motor, and a controller. The controller controls the operation of the motor, which then drives the rotation of the rotor pump to realize the operation of the electronic oil pump.

[0004] However, the conventional electronic oil pump has disadvantages such as complicated structure, large volume, high resistance, low stability, etc., and there is still room for improvement. Summary of the Invention

[0005] The present application aims to provide an electronic oil pump which has 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 connected to the fixed shaft for rotation; an external gear that is coaxially connected to the fixed shaft, rotatably connected within the pump casing, and located on an 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 an outer periphery of the rotor and fixedly connected to the pump casing; There is provided an electronic oil pump comprising 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 in a plane passing through the axis of the fixed shaft.

[0007] By using the above technical proposal, an external gear is provided inside the motor rotor, and the external gear is integrated and integrated with the motor rotor. Such a design has the following advantages. First, it reduces the height of the electronic oil pump, greatly reduces the volume of the system, reduces the weight of the system, and significantly reduces the material and production costs of the system. Second, the height of the oil pump is reduced, shortens the path of the pressurized cooling oil, effectively reduces the friction of the rotor pump chamber, and is favorable to improving the efficiency of the system. Third, the structure is simple, reduces the accumulated installation error, improves the coaxiality of the motor rotor, the motor stator and the external gear, and avoids the risk of eccentricity of the air gap. Fourth, the structure is more stable, effectively reduces the vibration noise of the pump body during operation, improves the performance of the pump body, improves the reliability of the pump body, and extends the working life of the pump body.

[0008] In some embodiments, the pump further comprises 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 is rotatably connected to the pump casing via the second bearing, and the other end of the fixed shaft is coaxially connected to the external gear.

[0010] The conventional mounting of the fixed shaft and the pump casing is realized by designing a step at the bottom of the pump casing, where the fixed end of the fixed shaft is screwed to the nut through the step, and the nut abuts against the end face of the step, and the frictional force caused by the abutment of the nut and the step realizes the fixed connection between the fixed shaft and the pump casing. However, the tightness of the nut mounting affects the clearance of the axial end face of the pump body. In the working state, the temperature inside the pump casing increases, and the difference in the thermal expansion coefficient of the materials of the pump casing, the fixed shaft and the nut (such as the aluminum material of the pump casing, the stainless steel material of the fixed shaft, and the steel material of the nut) changes the clearance of the axial end face, which further affects the performance of the pump body. By using the above technical solution, the bearing is directly connected to the fixed shaft, which reduces the aspect ratio in the electronic oil pump. The large diameter bearing and the rotating shaft have a large aspect ratio, which reduces the structural stability of the electronic oil pump, and the motor and pump gear have low concentricity with the rotating shaft when the electronic oil pump is working. By installing a small-sized bearing at the bottom of the rotating shaft, many advantages can be realized. For example, the pump body structure system has a small aspect ratio, the pump body structure is more stable, and the concentricity of the motor, the pump gear and the rotating shaft can be effectively improved. Secondly, the difficulty of assembling the gear pump structure, the rotating shaft and the pump body chassis is greatly simplified, which contributes to the concentricity of the pump body system structure, and contributes to improving the air gap precision of the motor stator and the motor rotor, so that the motor operation is always in a precise and uniform magnetic field distribution, the motor operation is more stable, and the utilization efficiency of the motor magnetic field is higher, and finally ensures that the electronic oil pump works efficiently. Secondly, the large-area contact interface between the large-sized bearing and the outer gear of the gear pump and the pump body chassis is reduced, which reduces the assembly deviation accumulation caused by multiple contact interfaces, which reduces the friction resistance generated during the rotation operation of the pump body structure, which reduces the large centrifugal degree generated during the rotation of the large-sized bearing, which reduces the influence of the axial and radial end face gaps of the pump body caused by the thermal expansion of different materials due to temperature, which improves the efficiency and stability of the electronic oil pump.

[0011] In some embodiments, the electronic oil pump further comprises an eccentric calibration piece located between the fixed shaft and the internal gear, the eccentric calibration piece being a half-moon sleeve provided on a circumferential outer wall of the fixed shaft, the half-moon sleeve being provided with an arc groove into which the fixed shaft is fitted, the half-moon sleeve being provided 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 the concentricity deviation caused by the processing and assembly of multiple components, such as the pump casing, the fixed shaft and the motor, and effectively ensure the concentricity of the pump casing, the fixed shaft and the motor. In this way, the external gear and the fixed shaft are rotatably connected, and at the same time, the eccentric assembly is also rotatably connected to the internal gear, so that the effect of coaxiality and eccentricity between the internal gear and the external gear can be realized. At the same time, since the fixed shaft and the pump casing are arranged concentrically, the motor rotor realizes high concentricity with the fixed shaft and the pump casing through the fixed shaft, and can effectively compensate for the lack of concentricity accuracy caused by the tolerance accumulation caused by 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 semicircular sleeve form an eccentric assembly that is rotatably connected to the internal gear, thereby realizing the effect of coaxiality and eccentricity between the internal gear and the external gear, effectively compensating for the lack of eccentricity of the motor center and axis center caused by the accumulation of tolerances during processing and assembly, and also maintaining the mutual drive by centrifugal force between the internal gear and external gear of the rotor pump.

[0013] In some embodiments, the gear further comprises a bushing, the internal gear being 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, a plurality of huff-and-puff oil chambers are formed by being surrounded by the external gear and the internal gear, the volume of the huff-and-puff oil chambers first increases stepwise along the rotation direction of the external gear and then decreases stepwise, the pump casing is provided with an oil inlet and an oil drain hole, when the huff-and-puff oil chamber increases stepwise, the oil inlet of the huff-and-puff oil chamber corresponds to the oil inlet hole, and when the huff-and-puff oil chamber decreases stepwise, the oil drain port of the huff-and-puff oil chamber 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, the circumferential inner wall of the inner circle of the external gear, the inner end surface of the outer circle of the external gear and the circumferential outer wall of the internal gear are surrounded to form a number of closed huff-and-puff oil chambers. When the internal gear and the external gear rotate relatively, the huff-and-puff oil chambers suck oil through the oil supply hole in a step-up process, the amount of oil in the huff-and-puff oil chamber increases with the increase in volume, and the low-temperature oil contacts the teeth of the internal gear and the external gear during the oil sucking, and the oil absorbs the heat of the teeth. The huff-and-puff oil chambers discharge oil through the oil drain hole in a step-down process, the amount of oil in the huff-and-puff oil chamber decreases with the decrease in volume, and the oil that absorbs heat and becomes hot during the oil sucking is discharged from the pump body through the oil drain hole, thus realizing the cooling and lubrication of the internal gear and the external gear, and the cooling of the pump body, and ensuring the working 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 is provided on the hub, the motor stator is provided with a plurality of stator windings in its circumferential direction, the motor rotor is fitted onto the circumferential outer circle of the external gear, and the circumferential outer wall of the motor rotor corresponds 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, and after the multiple stator windings are energized, the generated magnetic field and the permanent magnetic field of the rotor magnet interact 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 to drive the external gear of the rotor gear pump to rotate, and further the external gear of the rotor gear pump drives the internal gear to rotate, and the relative rotation between the internal gear and the external gear is realized.

[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 in the horizontal and axial directions, which is conducive to sealing, reducing oil leakage, and forming 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 the present application has a reduced height, a smaller system volume, a reduced weight, and a reduced cost. It has a simple structure, high assembly precision, high operating efficiency, and a longer operating life.

[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, the pump gear and the rotating shaft. Such a design greatly reduces the difficulty of assembling the gear pump structure, the rotating shaft and the pump body chassis, contributes to the concentricity of the pump body system structure, contributes to improving the air gap precision of the motor stator and the motor rotor, ensures that the motor operation is always in a precise and uniform magnetic field distribution, makes the motor operation more stable and precise, and makes the utilization efficiency of the motor magnetic field higher, and finally ensures that the electronic oil pump runs efficiently.

[0025] 3. When the second bearing is used, 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 during the rotation operation of the pump body structure, reducing the large centrifugal force generated during the rotation of the large-sized bearing, improving the effect of the electronic oil pump, and improving the stability of the electronic oil pump.

[0026] 4. The second bearing is provided 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 of the pump body and radial clearances, and avoiding the thermal expansion effect caused by the material temperature coefficients of different parts when the temperature changes. At the same time, the second bearing makes the structure of the electronic pump more stable, effectively reducing the vibration noise during the operation of the pump body, improving the NVH performance of the pump body, improving the reliability of the pump body, and extending the working life of the pump body. [Brief description of the drawings]

[0027] [Figure 1] FIG. 1 is a schematic diagram showing the external structure of a first embodiment of an electronic oil pump according to the present application. [Diagram 2] FIG. 2 is a schematic perspective sectional view of the first embodiment of the electronic oil pump of the present application. [Diagram 3] FIG. 3 is a schematic diagram of the internal structure of the first embodiment of the electronic oil pump of the present application. [Figure 4] FIG. 4 is a structural schematic diagram of a motor stator of the first embodiment of the electronic oil pump of the present application. [Diagram 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 schematic perspective sectional 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, the external gear and the 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, the internal gear, and the external gear of the electronic oil pump according to the second embodiment of the present application. [Figure 9] FIG. 9 is a schematic diagram of the bottom structure 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 schematic perspective sectional view of a third embodiment of the electronic oil pump of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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. In general, the assemblies of the embodiments of the present invention described and illustrated 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 are 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, further definition and explanation is not required in the subsequent figures.

[0030] In the description of the present invention, it should be explained that unless there is a clear specification and limitation, the terms "attached", "connected", "connected" and the like should be broadly understood, for example, they may be fixedly connected, detachably connected, or 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 meaning of the above terms in the present invention according to the specific situation.

[0031] In the description of this application, orientations or positional relationships indicated by technical terms such as "upper", "lower", "left", "right" and the like are based on those shown in the accompanying drawings and are merely intended to facilitate and simplify the description of this application, and do not indicate or suggest that the referred to devices or elements have a particular orientation or must 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 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 on the side wall of the pump casing 1, an oil supply hole 11 is provided on the bottom of the pump casing 1, and a filter 14 is provided on the bottom of the pump casing 1, which is located at the oil supply hole 11 and covers the oil supply hole 11.

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

[0035] The gear set includes an external gear 2 integrated and fixed with the motor rotor 8, and an internal gear 3 located in the external gear 2 and meshing with the internal teeth of the external gear 2. The internal gear 3 and the fixed shaft 4 are eccentrically rotatably connected, and eccentricity means that the rotation axes are not coincident. The external gear 2 and the fixed shaft 4 are coaxially connected and rotatably connected in the pump casing 1. The external gear 2 of the present invention is integrated with the motor rotor 8 and pressed together as one unit. Such a design, on the one hand, greatly reduces the volume of the system, reduces the weight of the system, obviously reduces 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 portion, improving airtightness, and ensuring that the controller 91 operates at an appropriate temperature. A PTC temperature sensor (not shown) for detecting and feeding back the cooling oil temperature is attached to the chassis 15, 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 flow efficiency of the system.

[0038] During operation, the circuit control module 9 controls the plurality of stator windings 94 to be energized, and the resulting magnetic field and the permanent magnetic field of the magnets of the motor rotor 8 interact with each other 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 of 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 the relative rotation between the internal gear 3 and the external gear 2.

[0039] In particular, in a plane passing through the axis of the fixed shaft 4, 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. 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 used for horizontal and axial deformation, which is helpful for sealing, reducing oil leakage, forming high pressure, and is economical and efficient, easy to assemble, has a long service life, and is easy to maintain.

[0041] In some embodiments, the electronic oil pump further comprises a top 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 and fixedly connected to the external gear 2 via the top 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, this embodiment further includes a sensor 26, for example a magnetic inductor, 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, make the distribution of the lint regular and clear, and weld the lint to the hub 92, which is a simple and concise process. Another role of the hub 92 is to separate the controller 91 from the motor part, so that the oil flows only through the motor part, a cooling and lubrication circuit is formed, and the oil does not enter 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 fast 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, receiving and calculating motor rotation speed comparison, and comparing and adjusting the actual rotor rotation speed.

[0046] Since the overall height of the electronic oil pump is reduced, the time it takes for pressurized cooling oil to flow to the stator assembly is shorter in this embodiment than in the conventional electronic oil pump, and the temperature reduction effect is more excellent.

[0047] Referring to FIG. 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, which drives 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] When the internal gear 3 and the external gear 2 rotate relatively, the huff-and-puff oil chamber 21 expands stepwise and sucks in oil through the oil supply hole 11, so the amount of oil in the huff-and-puff oil chamber 21 increases with the increase in volume. In this case, during the oil suction process, the low-temperature oil comes into contact with the teeth of the internal gear 3 and the external gear 2, and the oil absorbs the heat of the teeth. Then, as the huff-and-puff oil chamber 21 decreases stepwise, the oil is discharged through the oil drain hole 12, and the amount of oil in the huff-and-puff oil chamber 21 decreases with the decrease in volume. In this case, during the oil suction process, the high-temperature oil after suctioning the heat is discharged from the oil drain hole 12 to the outside of the pump body, thereby realizing the cooling and lubrication of the internal gear 3 and the external gear 2, and at the same time, the cooling of the pump body.

[0049] 5, a pump casing bottom 13 that covers the oil supply hole 11 and the oil drain hole 12 is integrally formed at the bottom of the pump casing 1. A fixing hole 131 is formed at the bottom of the pump casing 1, and the fixing hole 131 is provided eccentrically with respect to the pump casing 1. The fixed shaft 4 is provided in the fixing hole 131, and the circumferential outer wall of the fixed shaft 4 and the hole wall of the fixing hole 131 are firmly fitted together. A sliding bearing may be provided between the internal gear 3 and the pump casing 1 to reduce rotational resistance and improve the operating life. An oil suction port 132 communicating with the oil supply hole 11 and an oil drain port 133 communicating with the oil drain hole 12 are formed at the end face of the pump casing bottom 13. A partition 134 is formed at the bottom 13 of the pump casing to separate the oil suction port 132 and the oil discharge port 133. 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 there is no extra accessory. The advantages of this design are that the structure of the gear pump is simplified, the difficulty of assembling the rotating shaft and the pump body chassis is reduced, the concentricity between the motor, the shell and the gear set is improved, and it is favorable to ensure the concentricity of the pump body system structure, it is conducive to improving the air gap between the motor stator and the motor rotor, the motor operation is always located in a precise and uniform magnetic field distribution, the motor operation is more stable and precise, and the utilization efficiency of the motor magnetic field is increased, and finally, it ensures the high-efficiency operation of the electronic oil pump, it reduces the assembly deviation accumulation caused by multiple contact interfaces, it effectively reduces the friction resistance generated during the rotation operation of the pump body structure, it reduces the large centrifugal degree generated during the rotation of the large-sized bearing, it improves the efficiency of the electronic oil pump, it improves the stability of the electronic oil pump, it 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. As shown in FIG.

[0052] 6 to 8, the external gear 2 in this embodiment has an external gear inner circle 23 meshing with the internal gear 3, and the inner circle of the motor rotor is fixedly fitted on the external gear outer circle. The permanent magnet of the motor rotor 8 is fixed on the outer periphery of the motor rotor outer circle 24, and an air gap 16 is provided between the permanent magnet of the motor rotor 8 and the stator winding 94. In the research and development process, it is necessary to minimize the influence of various factors on the stability of the distance of the air gap 16. The motor rotor neck 22 is integrally molded on the top of the motor rotor outer circle 24, and a bearing 6 is installed in 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, and the ball bearing 6 is installed at the end of the rotor pump so that there is no cavity between the motor and the rotor pump, reducing the height of the electronic oil pump and greatly reducing the weight and volume of the rotor pump. In the embodiment, the ball bearing 6 is machined on 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 provided at the bottom of the pump casing 1, and the fixing hole 131 is arranged concentrically with the pump casing 1. The fixed shaft 4 is provided through the fixing hole 131, and the fixed shaft 4 and the bearing 6 are firmly fitted together. The motor rotor neck 22 fitted to the bearing 6 is integrally formed 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 on the eccentric assembly. The internal gear 3 is eccentrically connected to the fixed shaft 4 by the eccentric calibration piece 5 so as to be rotatable, and eccentric means that the rotation axis does not coincide. The eccentric calibration piece 5 is a half-moon sleeve provided on the circumferential outer wall of the fixed shaft 4. The half-moon sleeve is provided with an arc groove 51 into which the fixed shaft 4 is fitted, and the half-moon sleeve is provided so as to eccentrically connect the internal gear 3 to the fixed shaft 4 so as to be rotatable. The motor rotor inner circle is provided so as to be bonded to the external gear outer circle in the axial direction. The 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 the huff-and-puff oil chambers 21 increases stepwise in the rotation direction of the external gear 2 and then decreases stepwise, 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 stepwise, 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 stepwise, 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 covering the oil supply hole 11 and the oil drain hole 12 is integrally formed at the bottom of the pump casing 1, and a fixing hole 131 fixedly connected to one end of the fixed shaft 4 is formed in the axial direction of the end face of the pump casing bottom 13. The fixed shaft 4 is inserted into the fixing hole 131, and the circumferential outer wall of the fixed shaft 4 and the hole wall of the fixing hole 131 are firmly fitted together, 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 drain 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 at the bottom 13 of the pump casing to separate the oil suction port 132 and the oil discharge port 133. 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, 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 a hole formed therein to match 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 fitting accuracy of the external gear 2 and the internal gear 3.

[0058] The implementation principle of the highly accurate electronic oil pump of the embodiment of the present application 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 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. This embodiment uses a statically fixed design for the fixed shaft 4, and when driven by the external gear 2, the pump internal gear 3 rotates relative to the fixed shaft 4, lubricating each other, reducing friction, reducing the wear of the rotor pump system, and effectively improving 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, so that 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 directly 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 sensing its position.

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

[0066] 1) First, the equipment is turned on. 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 rotated 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 of the pressurized cooling oil flows to the stator assembly via the fixed shaft 4 and cools the stator assembly, and the cooling oil that has been heat exchanged flows again to the low pressure area, and the cooling oil is pressurized by the centrifugal force caused by the difference between the internal and external gears. In this case, the PTC temperature sensor detects the current oil temperature value and feeds this temperature value back to the controller 91, which 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 above shows and describes the basic principle, main features and advantages of the present invention. 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 in 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 claims of the present invention. [Explanation of symbols]

[0070] 1. Pump casing 11. Oil hole 12, oil drain hole 13. Bottom of pump casing 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 connected to the fixed shaft (4) for rotation; 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); 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 rotor and fixedly connected to the pump casing (1); In a plane passing through the axis of the fixed shaft (4), the projected areas of the motor stator (93), the motor rotor, the external gear (2), the internal gear (3) and the fixed shaft (4) at least partially overlap. An electronic oil pump.

2. The external gear (2) is rotatably connected to one end of the fixed shaft (4) via a first bearing (6), and the other end of the fixed shaft (4) is connected to the pump casing (1).

2. The electronic oil pump according to claim 1.

3. 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).

2. The electronic oil pump according to claim 1.

4. 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 being provided with an arc groove (51) into which the fixed shaft (4) is fitted, and the half-moon sleeve is provided to eccentrically rotatably connect the internal gear (3) to the fixed shaft (4).

4. The electronic oil pump according to claim 1, wherein the oil pump is a pump having a first diameter of 100 mm.

5. The internal gear (3) is rotatably connected to the half-moon sleeve and the fixed shaft (4) by means of a bushing (7).

5. The electronic oil pump according to claim 4.

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

2. The electronic oil pump according to claim 1.

7. A plurality of huff-and-puff oil chambers (21) are formed by being surrounded by the external gear (2) and the internal gear (3), the volume of the huff-and-puff oil chambers (21) first increases stepwise along the rotation direction of the external gear (2) and then decreases stepwise, 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 stepwise, the oil supply port of the huff-and-puff oil chambers (21) corresponds to the oil supply hole (11), and when the huff-and-puff oil chambers (21) decrease stepwise, the oil drain port of the huff-and-puff oil chambers (21) corresponds to the oil drain hole (12).

4. The electronic oil pump according to claim 1, wherein the oil pump is a pump having a first diameter of 100 mm.

8. When the huff and puff oil chamber (21) increases stepwise, 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 stepwise, the cooling oil in the huff and puff oil chamber (21) is pushed out from the oil drain hole (12).

8. The electronic oil pump according to claim 7.

9. The pump further includes a motor rotor (8) and 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 around 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).

2. The electronic oil pump according to claim 1.

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

10. The electronic oil pump according to claim 9.

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