Electronic oil pump

Abstract

The utility model discloses an electronic oil pump which comprises a pump shell and further comprises a fixed shaft arranged in the pump shell. The inner gear and the fixed shaft deviate from the axis and are rotationally connected; the outer gear is coaxially connected with the fixed shaft and rotationally connected into the pump shell, and the outer gear is located on the periphery of the inner gear and meshed with the inner gear; the motor rotor is fixedly connected to the periphery of the outer gear; the motor stator is located on the periphery of the rotor and fixedly connected with the pump shell; on the plane penetrating through the axis of the fixed shaft, the projection areas of the motor stator, the motor rotor, the outer gear, the inner gear and the fixed shaft at least partially coincide. Due to the fact that the small-size bearing is adopted, the electronic oil pump has the advantages of being small in height, compact in structure, low in resistance, high in stability and the like.

Description

Technical Field

[0001] This application relates to the technical field of electronic oil pumps for new energy vehicles, and particularly relates to an electronic oil pump with low resistance and high stability. Background Art

[0002] With the rapid development of automotive electronics and new energy vehicles, integrated high-precision designed electronic oil pumps are increasingly used due to their high efficiency, energy conservation, and flexible control.

[0003] Currently, electronic oil pumps mainly consist of three parts: components such as 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 to achieve the operation of the electronic oil pump.

[0004] However, existing electronic oil pumps have disadvantages such as complex structure, large volume, high resistance, and low stability, so there is still much room for improvement. Utility Model Content

[0005] The purpose of this application is to provide an electronic oil pump, which has the advantages of compact structure, small volume, low resistance, good stability, and high working efficiency.

[0006] This application provides an electronic oil pump, including a pump housing, and further including:

[0007] A fixed shaft, disposed within the pump housing;

[0008] An internal gear, eccentrically and rotatably connected to the fixed shaft;

[0009] An external gear, coaxially connected to the fixed shaft and rotatably connected within the pump housing, the external gear being located outside the internal gear and meshing with the internal gear;

[0010] A motor rotor, fixedly connected to the outer periphery of the external gear;

[0011] A motor stator, located outside the rotor and fixedly connected to the pump housing;

[0012] Wherein, in a plane passing through the axis of the fixed shaft, the projections of the motor stator, the motor rotor, the external gear, the internal gear, and the fixed shaft at least partially overlap.

[0013] By adopting the above technical solution, an external gear is arranged inside the motor rotor, so that the external gear is integrated into the motor rotor and combined into one body. Such a design has the following advantages. First, the height of the electronic oil pump is reduced, the volume of the system is significantly reduced, the weight of the system is reduced, and the material and production costs of the system are significantly reduced. Second, the reduction of the oil pump height shortens the cooling oil path for pressurization, effectively reduces the friction of the rotor pump cavity, and is beneficial to improving the system efficiency. Third, the structure is simple, the cumulative installation error is reduced, the coaxiality of the motor rotor, the motor stator and the external gear is improved, and the hidden danger of air gap eccentricity is effectively avoided. Fourth, the structure is more stable, the vibration and noise during the operation of the pump body are effectively reduced, the performance of the pump body is improved, the reliability of the pump body is improved, and the working life of the pump body is extended.

[0014] In some embodiments, it further includes a bearing. The external gear is rotatably connected to one end of the fixed shaft through the bearing. The other end of the fixed shaft is connected to the pump housing. The external gear is connected to the outer circle of the motor rotor. The bearing is arranged between the outer circle of the motor rotor and the fixed shaft, and the end face of the bearing is not higher than the end face of the outer circle of the motor rotor.

[0015] In some embodiments, it further includes a bearing. One end of the fixed shaft is rotatably connected to the pump housing through the bearing. The other end of the fixed shaft is coaxially connected to the external gear.

[0016] The traditional installation of the fixed shaft and the pump housing is achieved by designing a step at the bottom of the pump housing. The fixed end of the fixed shaft passes through the step and is threadedly connected to a nut. The nut abuts against the end face of the step, and the frictional force generated by the abutment of the nut against the step realizes the fixed connection between the fixed shaft and the pump housing. However, the tightness of the nut installation affects the axial end face clearance of the pump body. During the working state, the temperature inside the pump housing rises. Due to the different thermal expansion coefficients of the materials of the pump housing, the fixed shaft and the nut (such as the aluminum material of the pump housing, the stainless steel material of the fixed shaft, and the steel material of the nut), the axial end face clearance will change, thereby affecting the performance of the pump body. By adopting the above technical solution, the bearing is directly connected to the fixed shaft, reducing the aspect ratio in the electronic oil pump. A large-diameter bearing has a large aspect ratio with the rotating shaft, making the structural stability of the electronic oil pump poor, resulting in a poor concentricity between the motor and the pump gear relative to the rotating shaft when the electronic oil pump is working. Installing a small-sized bearing at the bottom of the rotating shaft can achieve many advantages. For example, the pump body structure system has a smaller aspect ratio, the pump body structure is more stable, and it can effectively improve the concentricity of the motor, the pump gear, and the rotating shaft. Secondly, it greatly simplifies the assembly difficulty of the gear pump structure, the rotating shaft, and the pump body housing, which is beneficial to ensuring the concentricity of the pump body system structure, helps to improve the air gap accuracy between the motor stator and the motor rotor, enables the motor to always work in a precise and uniform magnetic field distribution, makes the motor work more stably, has a higher utilization efficiency of the motor magnetic field, and ultimately ensures the high-efficiency operation of the electronic oil pump. Thirdly, it reduces the large-area contact interface between the large-sized bearing and the outer gear of the gear pump and the pump body housing, reduces the accumulation of assembly deviations caused by multiple contact interfaces, effectively reduces the frictional resistance generated when the pump body structure rotates, reduces the large centrifugal force problem caused by the rotation of the large-sized bearing, reduces the influence of thermal expansion of different materials caused by temperature on the axial and radial end face clearances of the pump body, and improves the efficiency and stability of the electronic oil pump.

[0017] In some embodiments, the electronic oil pump further includes an eccentric calibration member located between the fixed shaft and the internal gear. The eccentric calibration member is a semi-circular sleeve provided on the circumferential outer wall of the fixed shaft. The semi-circular sleeve is provided with an arc-shaped groove for the fixed shaft to be embedded, and the semi-circular sleeve is arranged to enable the internal gear to be eccentrically rotationally connected to the fixed shaft. Preferably, the semi-circular sleeve is fixedly connected to the pump housing.

[0018] By adopting the above technical solution, the eccentric calibration part can compensate for the concentricity deviation caused by machining and assembly of multiple parts such as the pump housing, the fixed shaft, and the motor, thereby effectively ensuring the concentricity of the pump housing, the fixed shaft, and the motor. While the outer gear is rotatably connected to the fixed shaft, the eccentric assembly can be rotatably connected to the inner gear, achieving the effect that the inner gear and the outer gear are coaxial and eccentric. At the same time, since the fixed shaft is concentrically arranged with the pump housing, the motor rotor can achieve high concentricity with the fixed shaft and the pump housing by means of the fixed shaft, effectively compensating for the problem of insufficient concentric accuracy caused by the accumulation of tolerances due to machining and assembly. A circumferential side wall portion of the fixed shaft is partially embedded in the arc-shaped groove, so that the circumferential side wall of the fixed shaft and the circumferential outer wall of the half-moon sleeve form an eccentric assembly rotatably connected to the inner gear, achieving the effect that the inner gear and the outer gear are coaxial and eccentric, effectively compensating for the problem of insufficient eccentricity between the center of the motor and the axis caused by the accumulation of tolerances due to machining and assembly, and also maintaining the mutual drive of the inner gear and the outer gear of the rotor pump based on the centrifugal design.

[0019] In some embodiments, it further includes a shaft sleeve, and the inner gear is rotatably connected to the half-moon sleeve and the fixed shaft through the shaft sleeve.

[0020] By adopting the above technical solution, the shaft sleeve can reduce the friction between the inner gear and the fixed shaft and the half-moon sleeve, reduce the frictional resistance, and improve the rotation efficiency.

[0021] In some embodiments, a plurality of oil intake and discharge cavities are formed by enclosing between the outer gear and the inner gear. The volume of the oil intake and discharge cavity first increases step by step and then decreases step by step along the rotation direction of the outer gear. The pump housing is provided with an oil inlet hole and an oil outlet hole. When the oil intake and discharge cavity increases step by step, the oil inlet of the oil intake and discharge cavity corresponds to the oil inlet hole. When the oil intake and discharge cavity decreases step by step, the oil outlet of the oil intake and discharge cavity corresponds to the oil outlet hole.

[0022] In some embodiments, when the oil intake and discharge cavity increases step by step, the cooling oil flows into the oil intake and discharge cavity through the oil inlet hole. When the oil intake and discharge cavity decreases step by step, the cooling oil in the oil intake and discharge cavity is pressed out from the oil outlet hole.

[0023] By adopting the above technical solution, a plurality of closed oil intake and discharge cavities are enclosed by the circumferential inner wall of the inner circle of the outer gear, the inner side end face of the outer circle of the outer gear, and the circumferential outer wall of the inner gear. When the inner gear and the outer gear rotate relative to each other, the oil intake and discharge cavity intakes oil through the oil inlet hole during the process of increasing step by step. The amount of oil in the oil intake and discharge cavity increases as the volume increases. During the oil intake process, the oil with a lower temperature contacts the teeth of the inner gear and the outer gear, and the oil absorbs the heat of the teeth. The oil intake and discharge cavity discharges oil through the oil outlet hole during the process of decreasing step by step. The amount of oil in the oil intake and discharge cavity decreases as the volume decreases. The oil with a higher temperature after absorbing heat during the oil intake process is discharged from the oil outlet hole out of the pump body, thereby realizing the cooling and lubrication of the inner gear and the outer gear and the cooling of the pump body, ensuring the working temperature and efficiency of the pump.

[0024] In some embodiments, a circuit control module is further included. The circuit control module includes a controller and a hub disposed within the pump housing. The motor stator is disposed on the hub. A plurality of stator windings are circumferentially disposed along the motor stator. The motor rotor is sleeved on the outer circumferential surface of the outer gear, and the outer circumferential wall of the motor rotor corresponds to the inner circumferential wall of the motor stator.

[0025] By adopting the above technical solution, the controller controls the hub to energize a plurality of stator winding coils on the motor stator. After the plurality of stator windings are energized, a magnetic field is generated and interacts with the permanent magnetic field of the rotor magnet to drive the motor rotor to rotate. The motor rotor is integrated on the outer rotor of the gear pump, that is, the interaction between the motor stator and the rotor magnet drives the outer gear pump of the rotor to rotate, and the outer gear of the rotor gear pump further drives the inner gear to rotate, realizing the relative rotation of the inner gear and the outer gear.

[0026] In some embodiments, an O-ring seal is further provided on the outer periphery of the pump housing.

[0027] In the above technical solution, the O-ring seal can be deformed in the horizontal and axial directions, which is beneficial to sealing, reducing oil leakage and forming high pressure. It is economical and efficient, easy to assemble, has a long service life, and is convenient for maintenance.

[0028] In summary, the present application can achieve at least one of the following beneficial technical effects:

[0029] 1. The electric oil pump of the present application reduces the height of the electric oil pump, reduces the system volume, reduces the weight, and reduces the cost. It has a simple structure, high assembly accuracy, high working efficiency, and extends the working life of the product.

[0030] 2. The electric oil pump in some embodiments of the present application has a smaller aspect ratio, the pump body structure is more stable, and can effectively improve the concentricity between the motor, the pump gear and the rotating shaft. This design can greatly reduce the assembly difficulty of the gear pump structure, the rotating shaft and the pump body housing, is beneficial to ensuring the concentricity of the pump body system structure, and is very helpful to increase the air gap between the motor stator and the motor rotor, so that the motor always works in a precise and uniform magnetic field distribution. The motor works more stably and precisely, has a higher utilization efficiency of the motor magnetic field, and finally ensures the high-efficiency operation of the electric oil pump.

[0031] 3. In the case of using bearings, the bearing size is reduced, thereby reducing the contact interface area between the bearing and the outer gear of the gear pump and the pump body housing, reducing the accumulation of assembly deviations caused by multiple contact interfaces, effectively reducing the frictional resistance generated during the rotation of the pump body structure, reducing the large centrifugal force generated during the rotation of the large-size bearing, improving the efficiency of the electric oil pump, and improving the stability of the electric oil pump.

[0032] 4. By setting up bearings, the bottom of the rotating shaft is fixed integrally with the pump body housing, and the upper part of the shaft is directly connected to the outer gear top cover, ensuring precise end face clearance and radial clearance of the pump body, and avoiding the thermal expansion effect caused by the different temperature coefficients of different materials of different components when the temperature changes. At the same time, by setting up bearings, the structure of the electronic pump is more stable, effectively reducing the vibration and noise during the operation of the pump body, improving the NVH performance of the pump body, enhancing the reliability of the pump body, and extending the working life of the pump body. Description of the Drawings

[0033] Figure 1 is a schematic diagram of the external structure of the first embodiment of the electronic oil pump of the present application;

[0034] Figure 2 Schematic diagram of the three-dimensional sectional structure of the first embodiment of the electronic oil pump of the present application;

[0035] Figure 3 is a schematic diagram of the internal structure of the first embodiment of the electronic oil pump of the present application;

[0036] Figure 4 is a schematic diagram of the structure of the motor stator of the first embodiment of the electronic oil pump of the present application;

[0037] Figure 5 is a schematic diagram of the pump housing structure of the first embodiment of the electronic oil pump of the present application;

[0038] Figure 6 Schematic diagram of the three-dimensional section of the second embodiment of the electronic oil pump of the present application;

[0039] Figure 7 is a schematic diagram of the structures of the circuit control module, outer gear and inner gear of the second embodiment of the electronic oil pump of the present application;

[0040] Figure 8 is a schematic diagram of the structural cooperation of the motor stator, inner gear and outer gear of the second embodiment of the electronic oil pump of the present application;

[0041] Figure 9 is a schematic diagram of the structure of the bottom of the pump housing of the second embodiment of the electronic oil pump of the present application;

[0042] Figure 10 is a schematic diagram of the structures of the outer gear and inner gear of the second embodiment of the electronic oil pump of the present application;

[0043] Figure 11 is a schematic diagram of the structure of the eccentric calibration part of the second embodiment of the electronic oil pump of the present application;

[0044] Figure 12 is a schematic diagram of the three-dimensional section of the third embodiment of the electronic oil pump of the present application.

[0045] Description of reference numerals: 1. Pump housing; 11. Oil inlet hole; 12. Oil outlet hole; 13. Bottom of the pump housing; 131. Fixing hole; 132. Oil swallowing port; 133. Oil spitting port; 134. Partition part; 135. Assembly guiding hole; 14. Filter net; 15. Machine housing; 16. Air gap; 17. Sealing ring; 2. Outer gear; 21. Oil swallowing and spitting chamber; 22. Neck of the motor rotor; 23. Inner circle of the outer gear; 24. Outer circle of the motor rotor; 25. Upper cover; 26. Sensor; 3. Inner gear; 4. Fixed shaft; 41. Eccentric assembly; 5. Eccentric calibration part; 51. Arc-shaped groove; 52. Positioning hole; 6. Bearing; 7. Bush; 8. Motor rotor; 9. Circuit control module; 91. Controller; 92. Hub; 93. Motor stator; 94. Stator winding. Detailed implementation manners

[0046] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings. The components of the embodiments of the present utility model described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0047] It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0048] In the description of the present utility model, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0049] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0050] The following will describe in detail the embodiments of the present utility model with reference to the accompanying drawings. Without conflict, the features in the following embodiments can be combined with each other.

[0051] Embodiment 1

[0052] Please refer to Figures 1-5 , this embodiment discloses an electronic oil pump. Please refer to Figure 1 , the electronic oil pump includes a pump housing 1. In some embodiments, the pump housing 1 is made of aluminum. An oil outlet hole 12 is provided on the side wall of the pump housing 1, an oil inlet hole 11 is provided at the bottom of the pump housing 1, and a filter net 14 covering the oil inlet hole 11 is provided at the bottom of the pump housing 1 at the position of the oil inlet hole 11.

[0053] Please refer to Figures 2-4 , a fixed shaft 4, a motor, a circuit control module 9 and a gear set are installed in the pump housing 1. The motor includes a motor rotor 8, a motor stator 93 and a stator winding 94. The motor stator 93 is fixed in the pump housing 1, the motor rotor 8 is arranged in the motor stator 93, and multiple groups of stator windings 94 are arranged in a circumferential array around the motor stator 93 and are located between the motor rotor 8 and the motor stator 93.

[0054] The gear set includes an external gear 2 integrally fixed with the motor rotor 8, and an internal gear 3 located inside the external gear 2 and meshing with the internal teeth of the external gear 2. The internal gear 3 is eccentrically rotationally connected to the fixed shaft 4, and eccentricity means that the rotation axes do not coincide. The external gear 2 is coaxially connected to the fixed shaft 4 and is rotationally connected in the pump housing 1. In the present utility model, the external gear 2 is integrated into the motor rotor 8 and pressed into one body. Such a design can, on the one hand, greatly reduce the volume of the system, reduce the weight of the system, and significantly reduce the system material and production costs; on the other hand, it can effectively reduce the friction in the rotor pump cavity and is beneficial to improving the system efficiency.

[0055] The pump housing 1 is provided with a housing 15 for separating the controller 91 and the hub 92, which is used to separate the oil circuit and the electronic control part, improve the sealing performance, and ensure that the controller 91 works at an appropriate temperature. A PTC temperature sensor (not marked in the figure) for detecting and feedbacking the temperature of the cooling oil is installed on the housing 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.

[0056] Since the external gear is integrated into the motor rotor, the thermal expansion coefficients of the motor stator 93 and the pump body are the same, so it can greatly reduce the influence of temperature on the oil pump clearance, accurately ensure the pump end face clearance, and effectively reduce or avoid the influence of temperature on the system flow efficiency.

[0057] During the operation process, the circuit control module 9 controls multiple stator windings 94 to be energized, and then the generated magnetic field interacts with the permanent magnetic field of the magnet of the motor rotor 8 to drive the motor rotor 8 to rotate. The motor rotor 8 is fixed to the external gear 2, that is, the motor stator 93 and the magnet of the motor rotor 8 interact to drive the external gear 2 to rotate, and the external gear 2 further drives the internal gear 3 to rotate, realizing the relative rotation of the internal gear 3 and the external gear 2.

[0058] Specifically, on the 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. This structure can reduce the axial height of the electric oil pump, making it compact and small in size.

[0059] A sealing ring is also provided on the outer periphery of the pump housing 1. In some embodiments, the sealing ring is an O-ring 17 made of rubber. The O-ring 17 is used for horizontal and axial deformation, which is beneficial for sealing, reducing oil leakage, and forming high pressure. It is economical and efficient, easy to assemble, has a long service life, and is convenient for maintenance.

[0060] In some embodiments, the electric oil pump further includes an upper cover 25 fixedly connected to the external gear 2. One end of the fixed shaft 4 is rotatably connected to the pump housing 1 through a bearing 6, and the other end of the fixed shaft 4 is coaxially and fixedly connected to the external gear 2 through the upper cover 25. The internal gear 3 is eccentrically connected to the fixed shaft 4 through the pump housing 1, and the internal gear 3 is rotatably connected to the pump housing 1.

[0061] For the cold start of the high-power electric oil pump, a sensor 26, such as a magnetic current transformer, is fixedly connected to the top end of the fixed shaft 4 in this embodiment. In other embodiments, the sensor 26 can also be fixedly connected to the upper cover 25 fixedly connected to the external gear 2.

[0062] The circuit control module 9 includes a hub 92 disposed inside the pump housing 1 and above the motor, and a controller 91 above the hub 92. The function of the hub 92 is to collect the incoming and outgoing wires of the stator winding 94, making the wire heads neatly and clearly distributed, and welding the wire heads on the hub 92, with a simple and clean process. Another function of the hub 92 is to separate the controller 91 from the motor part, so that the oil fluid only circulates in the motor part, forming a cooling and lubricating circuit, and no oil fluid will enter the controller 91.

[0063] A hub 92 is provided above the stator assembly. The pins of the stator winding 94 pass through the hub 92, simplifying the design of the electric control component and the traditional winding structure.

[0064] The controller 91 can achieve fast response, and has the characteristics of reverse circuit connection protection, prevention of signal interference, monitoring of oil temperature, prevention of overheating, having an independent communication channel, detecting the angular position of the motor, receiving and calculating the motor speed comparison, and adjusting the rationality of the actual rotor speed.

[0065] Since the height of the entire electric oil pump is reduced, compared with the traditional electric oil pump, the time for the pressurized cooling oil to flow to the stator assembly in this embodiment is short, and the cooling effect is better.

[0066] Please refer to Figure 2, the working process of the electronic oil pump is as follows: The controller 91 controls the hub 92 to energize multiple stator windings 94 on the motor stator 93. After the multiple stator windings 94 are energized, a magnetic field is generated to drive the motor rotor 8 to rotate. The motor stator 93 drives the outer gear 2 to rotate, realizing the relative rotation of the outer gear 2 and the inner gear 3.

[0067] When the inner gear 3 and the outer gear 2 rotate relative to each other, the oil intake and discharge cavity 21 gradually increases, and oil is ingested through the oil inlet hole 11. Therefore, the amount of oil in the oil intake and discharge cavity 21 increases as the volume increases. In this case, the oil at a lower temperature during the oil intake process contacts the teeth of the inner gear 3 and the outer gear 2, and the oil absorbs the heat of the teeth. Then, during the process of the gradual decrease of the oil intake and discharge cavity 21, oil is discharged through the oil outlet hole 12, and the amount of oil in the oil intake and discharge cavity 21 decreases as the volume decreases. In this case, the oil at a higher temperature after absorbing heat during the oil intake process is discharged from the oil outlet hole 12 out of the pump body, thereby realizing the cooling and lubrication of the inner gear 3 and the outer gear 2, and at the same time realizing the cooling of the pump body.

[0068] Please refer to Figure 5 , the bottom of the pump housing 1 is integrally formed with a pump housing bottom 13 covering the oil inlet hole 11 and the oil outlet hole 12. A fixing hole 131 is opened at the bottom of the pump housing 1, and the fixing hole 131 is eccentrically arranged with respect to the pump housing 1. The fixed shaft 4 is arranged in the fixing hole 131, and the outer circumferential wall of the fixed shaft 4 is tightly fitted with the hole wall of the fixing hole 131. A sliding bearing can be arranged between the inner gear 3 and the pump housing 1 to reduce the rotation resistance and improve the working life. The end face of the pump housing bottom 13 is provided with an oil intake port 132 communicating with the oil inlet hole 11 and an oil discharge port 133 communicating with the oil outlet hole 12. The pump housing bottom 13 is provided with a partition portion 134 for separating the oil intake port 132 and the oil discharge port 133, and one side of the partition portion 134 is attached to one side of the inner gear 3 to improve the sealing performance between the oil intake port 132 and the oil discharge port 133.

[0069] In this embodiment, the eccentric fit between the inner gear 3 and the outer gear 2 is realized through the eccentric fixing hole 131 of the pump housing, without redundant accessories. The advantages of this design are as follows: the structure of the gear pump is simple, reducing the assembly difficulty of the rotating shaft and the pump body housing; improving the concentricity between the motor, the housing and the gear set, which is beneficial to ensuring the concentricity of the pump body system structure; helping to increase the air gap between the motor stator and the motor rotor, so that the motor always works in a precise and uniform magnetic field distribution; the motor works more stably and precisely, with higher utilization efficiency of the motor magnetic field, ultimately ensuring the high-efficiency operation of the electronic oil pump; reducing the accumulation of assembly deviations caused by multiple contact interfaces, effectively reducing the frictional resistance generated during the rotational work of the pump body structure; reducing the large centrifugal force generated during the rotation of the large-size bearing, improving the efficiency of the electronic oil pump and the stability of the electronic oil pump; small volume, light weight and low cost.

[0070] Embodiment Two

[0071] Please refer to Figures 6-11 , the fixed-axis 4 eccentric connection structure of this embodiment is different from that of the first embodiment.

[0072] Please refer to Figures 6-8 , the external gear 2 of this embodiment includes an inner circle 23 of the external gear meshing with the internal gear 3, and the inner circle of the motor rotor is fixedly sleeved on the outer circle of the external gear. The permanent magnet of the motor rotor 8 is fixed on the outer periphery of the outer circle 24 of the motor rotor, and an air gap 16 is provided between the permanent magnet of the motor rotor 8 and the stator winding 94. During the R & D process, it is necessary to minimize the influence of various factors on the distance stability of the air gap 16. A motor rotor neck 22 is integrally formed at the top of the outer circle 24 of the motor rotor, and a bearing 6 is installed in the motor rotor neck 22. The bearing 6 supports the motor rotor 8 to ensure the rotation of the external gear 2 in the rotor pump. The 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, greatly reducing the weight of the rotor pump and the volume of the rotor pump. In this embodiment, the bearing 6 and the pump housing 1 are processed with the same mechanical jig, so that the two have very precise coaxiality and concentricity, and can precisely control the air gap eccentricity.

[0073] Please refer to Figures 6-9 , a fixing hole 131 is opened at the bottom of the pump housing 1, and the fixing hole 131 is concentrically arranged with the pump housing 1. A fixed shaft 4 is inserted into the fixing hole 131, and the fixed shaft 4 is tightly fitted with the bearing 6. A motor rotor neck 22 cooperating with the bearing 6 is integrally formed on one side of the external gear 2. The internal gear includes an inner circle of the internal gear coaxially cooperating with the fixed shaft 4 and abutting against the eccentric aggregate. The internal gear 3 is eccentrically rotatably connected to the fixed shaft 4 through an eccentric calibration member 5. Eccentricity means that the rotation axes do not coincide. The eccentric calibration member 5 is a semi-moon sleeve provided on the circumferential outer wall of the fixed shaft 4. The semi-moon sleeve is provided with an arc-shaped groove 51 for the fixed shaft 4 to be embedded, and the semi-moon sleeve is arranged to eccentrically rotatably connect the internal gear 3 and the fixed shaft 4. The axial direction of the inner circle of the motor rotor is set to fit the outer circle of the external gear. A motor rotor neck 22 cooperating with the bearing 6 is integrally formed on one side of the outer circle 24 of the motor rotor, and the motor rotor neck 22 and one side of the outer circle 24 of the motor rotor form a groove for the bearing 6 to be embedded. The circumferential outer wall of the bearing 6 is tightly fitted with the circumferential groove wall of the groove, which can reduce the working noise.

[0074] Please refer to Figures 9-11, the circumferential inner wall of the inner circle 23 of the outer gear and the circumferential outer wall of the inner gear 3 are both attached to the inner side end face of the outer circle 24 of the motor rotor. Multiple closed oil suction and discharge cavities 21 are formed by dividing the area between the outer gear 2 and the inner gear 3 through tooth-to-tooth contact. The volume of the oil suction and discharge cavity 21 first increases step by step and then decreases step by step along the rotation direction of the outer gear 2. An oil inlet hole 11 is integrally formed at the bottom of the pump housing 1, and an oil outlet hole 12 is integrally formed on the circumferential outer wall of the pump housing 1. When the oil suction and discharge cavity 21 increases step by step, the oil inlet of the oil suction and discharge cavity 21 corresponds to the oil inlet hole 11, and when the oil suction and discharge cavity 21 decreases step by step, the oil outlet of the oil suction and discharge cavity 21 corresponds to the oil outlet hole 12.

[0075] The bottom of the pump housing 1 is integrally formed with a pump housing bottom 13 covering the oil inlet hole 11 and the oil outlet hole 12. An axial fixing hole 131 for fixedly connecting one end of the fixed shaft 4 is formed on the end face of the pump housing bottom 13. The fixed shaft 4 is inserted into the fixing hole 131, and the circumferential outer wall of the fixed shaft 4 is tightly fitted with the hole wall of the fixing hole 131. A sliding bearing is arranged between the inner gear 3 and the pump housing 1 to reduce the rotation resistance and improve the working life. An oil suction port 132 communicating with the oil inlet hole 11 and an oil discharge port 133 communicating with the oil outlet hole 12 are formed on the end face of the pump housing bottom 13. The pump housing bottom 13 is provided with a partition 134 for separating the oil suction port 132 and the oil discharge port 133. One side of the partition 134 is attached to one side of the inner gear 3 to improve the sealing performance between the oil suction port 132 and the oil discharge port 133.

[0076] A positioning hole 52 is formed through one side of the half-moon sleeve. An assembly guiding hole 135 corresponding to the positioning hole 52 is formed on the pump housing bottom 13. The assembly guiding hole 135 and the fixing hole 131 are eccentrically arranged. A shaft sleeve 7 is arranged between the fixed shaft 4 and the inner gear 3 to reduce the sliding friction. The inner gear 3 is rotationally connected to the half-moon sleeve and the fixed shaft 4 through the shaft sleeve 7.

[0077] A hole matching the fixed shaft 4 is formed on the pump housing 1, which effectively reduces the complexity of the pump housing 1 processing, improves the processing efficiency of the pump housing 1, and improves the matching accuracy between the outer gear 2 and the inner gear 3.

[0078] The implementation principle of an electronically controlled fuel pump with a high-precision design in an embodiment of the present application is as follows:

[0079] A fixed shaft 4 is arranged in the pump housing 1, and an eccentric calibration part 5 is arranged on the circumferential side wall of the fixed shaft 4 to form an eccentric assembly 41. While the outer gear 2 is rotationally connected to the fixed shaft 4, the eccentric assembly 41 can also be rotationally connected to the inner gear 3, realizing the effect that the inner gear 3 and the outer gear 2 are coaxial and eccentric.

[0080] Embodiment III

[0081] Please refer to Figure 12, which is different from the first and second embodiments in that the bearing is arranged between the outer gear and the pump housing, and the fixed shaft 4 is of a hollow structure. In this embodiment, a flow channel for cooling oil to pass through is provided inside the fixed shaft 4. The fixed shaft 4 in this embodiment is designed for static fixation. Driven by the outer gear 2, the inner gear 3 in the pump rotates relative to the fixed shaft 4, lubricating each other to reduce friction, reducing the loss of the rotor pump system, and effectively improving the rotational stability of the rotor pump.

[0082] The mechanism of the cooling oil cooling the stator assembly in this embodiment is as follows:

[0083] The motor rotor 8 and the outer gear 2 jointly drive the inner gear 3 to rotate to pressurize the cooling oil flowing in from the oil inlet hole 11, so that one way of the pressurized cooling oil flows through the hollow flow channel of the fixed shaft 4 to the stator assembly to cool the stator assembly, and the cooling oil that has undergone heat exchange then flows back to the low-pressure area.

[0084] In addition, the other way of the pressurized cooling oil is directly discharged from the oil outlet hole 12 through the high-pressure area.

[0085] In this embodiment, a radial permanent magnet is also installed on the fixed shaft 4 to monitor its position.

[0086] The specific process of the cooling of the stator assembly by the present utility model is as follows:

[0087] 1) First, connect the device to the power supply. At this time, the controller 91 is powered on. The controller 91 converts the electricity into three-phase electricity to supply power to the stator winding 94. The electromagnetic force drives the motor rotor 8 and the outer gear 2 to rotate. The rotation of the motor rotor 8 and the outer gear 2 causes the cooling oil flowing in from the oil inlet hole 11 to enter the low-pressure area after passing through the filter screen 14;

[0088] 2) The motor rotor 8 and the outer gear 2 jointly drive the inner gear 3 to rotate around the fixed shaft 4 to pressurize the cooling oil flowing in from the oil inlet hole 11, so that one way of the pressurized cooling oil flows through the fixed shaft 4 to the stator assembly to cool the stator assembly, and the cooling oil that has undergone heat exchange then flows back to the low-pressure area, using the centrifugal force generated by the difference between the inner and outer gears to pressurize the cooling oil. At this time, the PTC temperature sensor feeds back the current temperature value of the oil and feeds this temperature value back to the controller 91. The controller 91 feeds back the current oil temperature value to the external control system;

[0089] 3) The other way of the pressurized cooling oil is directly discharged from the oil outlet hole 12 after passing through the high-pressure area.

[0090] The above has shown and described the basic principles, main features and advantages of the present utility model. Those skilled in the art should understand that the present utility model is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present utility model. Without departing from the spirit and scope of the present utility model, the present utility model will have various changes, modifications, substitutions and variations, and all of these changes, modifications, substitutions and variations fall within the scope of the present utility model claimed.

Claims

1. An electronic oil pump, comprising a pump housing (1), characterized in that: Also includes: A fixed shaft (4) is arranged in the pump housing (1); An internal gear (3) is eccentrically and rotationally connected to the fixed shaft (4); An external gear (2) is coaxially connected to the fixed shaft (4) and rotatably connected to the pump housing (1); the external gear (2) is 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 housing (1); Wherein, on a plane passing through the axis of the fixed shaft (4), the projection 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.

2. The electronic oil pump according to claim 1, characterized in that: The pump comprises a bearing (6), wherein the external gear (2) is rotatably connected to one end of the fixed shaft (4) via the bearing (6), the other end of the fixed shaft (4) is connected to the pump housing (1), the external gear (2) is connected to the outer circle (24) of the motor rotor, the bearing (6) is arranged between the outer circle (24) of the motor rotor and the fixed shaft (4), and the end surface of the bearing (6) is not higher than the end surface of the outer circle (24) of the motor rotor.

3. The electronic oil pump according to claim 1, characterized in that: It comprises a bearing (6), one end of the fixed shaft (4) is rotatably connected to the pump housing (1) via the bearing (6), and the other end of the fixed shaft (4) is coaxially connected to the external gear (2).

4. The electronic oil pump according to any one of claims 1 to 3, characterized in that: It also 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 arranged on the circumferential outer wall of the fixed shaft (4), the half-moon sleeve being provided with an arc groove (51) for the fixed shaft (4) to be embedded, and the half-moon sleeve being arranged to enable the internal gear (3) to be eccentrically rotatably connected to the fixed shaft (4).

5. The electronic oil pump according to claim 4, characterized in that: It also comprises a shaft sleeve (7), through which the internal gear (3) is rotatably connected to the half-moon sleeve and the fixed shaft (4).

6. The electronic oil pump according to claim 1, characterized in that: The fixed shaft (4) or the external gear (2) is fixedly connected with a sensor for cold starting.

7. The electronic oil pump according to any one of claims 1 to 3, characterized in that: A plurality of oil-throughput chambers (21) are enclosed between the external gear (2) and the internal gear (3). The volume of the oil-throughput chamber (21) increases step by step and then decreases step by step along the rotation direction of the external gear (2). The pump housing (1) is provided with an oil inlet hole (11) and an oil outlet hole (12). When the oil-throughput chamber (21) increases step by step, the oil inlet of the oil-throughput chamber (21) corresponds to the oil inlet hole (11), and when the oil-throughput chamber (21) decreases step by step, the oil outlet of the oil-throughput chamber (21) corresponds to the oil outlet hole (12).

8. The electronic oil pump according to claim 7, characterized in that: When the oil throughput chamber (21) increases step by step, cooling oil flows into the oil throughput chamber (21) through the oil inlet hole (11); when the oil throughput chamber (21) decreases step by step, cooling oil in the oil throughput chamber (21) is pressed out from the oil outlet hole (12).

9. The electronic oil pump according to claim 1, characterized in that: The pump also includes a circuit control module (9), wherein the circuit control module (9) includes a controller (91) and a hub (92) arranged in the pump housing (1), the motor stator (93) is arranged on the hub (92), the motor stator (93) is provided with a plurality of stator windings (94) along its circumference, the motor rotor (8) is sleeved on 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).

10. The electronic oil pump according to claim 9, characterized in that: An O-type sealing ring is also provided on the outer periphery of the pump housing (1).

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