Electronic oil pump

Abstract

Electronic Oil Pump The present invention discloses an electronic oil pump comprising a pump arch, and furthermore a fixed shaft disposed within the pump arch; an internal gear connected in an offset and rotatably to the fixed shaft; an external gear connected coaxially to the fixed shaft and rotatably connected within the pump arch, the external gear being located on the periphery of the internal gear and meshing with the internal gear; a motor rotor fixedly connected to the periphery of the external gear; and a motor stator located on the periphery of the rotor and fixedly connected to the pump arch; projection surfaces of the stator, rotor, external gear, internal gear, and fixed shaft coinciding at least partially in a plane passing through the axial center of the fixed shaft. Figure to be published with the abstract: Figure 1

Description

Title of the invention: Electronic oil pump Technical field

[0001] The present application relates to the technical field of electronic oil pump for new energy vehicles, in particular an electronic oil pump with low resistance and high stability. TECHNICAL CONTEXT

[0002] With the rapid development of automotive electronics and new energy vehicles, the integrated electronic oil pump with high precision design has been increasingly used due to high efficiency, energy saving and control flexibility.

[0003] At present, the electronic oil pump is essentially composed of three portions: a rotor pump, a motor and a controller, the controller controlling the motor to operate to drive the rotor pump to rotate, thereby realizing the operation of the electronic oil pump.

[0004] However, existing electronic oil pumps have the disadvantages such as structural complexity, large footprint, high strength and low stability and need to be improved. DISCLOSURE OF THE INVENTION

[0005] The present application aims to provide an electronic oil pump, which has the advantages such as compact structure, small size, low resistance, good stability and high operating efficiency, etc.

[0006] The present application provides an electronic oil pump, which comprises a pump arch and further comprises:

[0007] - a fixed shaft, which is arranged in the pump arch;

[0008] - an internal gear, which is connected in an offset and rotatable manner to the fixed shaft;

[0009] - an external gear, which is coaxially connected to the fixed shaft and is connected rotatably in the pump arch, and the outer gear being located at the periphery of the inner gear and meshing with the inner gear;

[0010] - a motor rotor, which is fixedly connected to the periphery of the gear exterior; and

[0011] - a motor stator, which is located on the periphery of the rotor and is fixedly connected to the pump arch;

[0012] wherein projection areas of the motor stator, the motor rotor, the external gear, the internal gear and the fixed shaft at least partially coincide in a plane passing through the axial center of the fixed shaft.

[0013] By adopting the above technical solution, by arranging the outer gear inside the motor rotor, the outer gear is integrated with the motor rotor to form a single-piece assembly. This design has the following advantages: I. The height of the electronic oil pump is reduced, the system volume is greatly reduced, the system weight is reduced, and the material and production costs of the system are greatly reduced. II. Reducing the height of the oil pump can shorten the path of the pressurized cooling oil, effectively reduce the friction at the cavity body of the rotor pump, and promote the improvement of the system efficiency. III.The structure is simple, which reduces the accumulated mounting error, improves the coaxiality between the motor rotor, the motor stator and the external gear, and effectively avoids the potential risk of air gap eccentricity. IV. The structure is more stable, which effectively reduces the vibration and noise of the pump body during operation, improves the performance of the pump body, improves the reliability of the pump body, and prolongs the service life of the pump body.

[0014] In some implementation solutions, the electronic oil pump further comprises a first bearing, the outer 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 arch.

[0015] In some implementation solutions, the electronic oil pump further comprises a second bearing, one end of the fixed shaft is rotatably connected to the pump arch via the second bearing and the other end of the fixed shaft is coaxially connected to the external gear.

[0016] The mounting of the fixed shaft and the pump arch in the prior art is achieved by providing a bearing at the bottom of the pump arch, wherein the fixed end of the fixed shaft passes through the bearing and is spun-connected to a nut, the nut bears against an end face of the bearing, and a friction force is generated by the nut bearing against the bearing, thereby achieving a fixed connection between the fixed shaft and the pump arch. However, the tightening level of the nut during mounting will affect a clearance of the axial end face of the pump body.In the working state, the temperature inside the pump arch rises, and due to the different thermal expansion coefficients of the materials of the pump arch, fixed shaft, and nut (for example, the pump arch is aluminum, the fixed shaft is stainless steel, and the nut is steel), the axial end face clearance will change, which will affect the performance of the pump body. By adopting the above technical solution, the bearing is directly connected to the fixed shaft, which can reduce the aspect ratio of the electronic oil pump. A large diameter bearing has a high aspect ratio compared to the rotating shaft, which makes . The structural stability of the electronic oil pump is poor and results in poor concentricity of the motor and pump gear relative to the rotating shaft when the electronic oil pump is working. Using a smaller bearing to be mounted at the bottom of the rotating shaft has many advantages. For example, firstly, the pump body structure system has a smaller aspect ratio, the pump structure is more stable, and the concentricity of the motor, pump gear, and rotating shaft can be effectively improved.Secondly, the assembly difficulty of the gear pump structure, rotating shaft and pump body is greatly reduced, thereby ensuring the concentricity of the pump body system structure and improving the accuracy of the air clearance between the motor stator and the motor rotor, in this way, the motor operation is always in a magnetic field with precise and uniform distribution, the motor operation is more stable, the motor uses the magnetic field more efficiently, and finally the high-efficiency operation of the electronic oil pump is ensured.Third, the large-area contact interface between the large-size bearing and the outer gear of the gear pump and the pump body casing is reduced, the assembly accumulated gap caused by multiple contact interfaces is reduced, the sliding resistance generated by the rotation of the pump body structure is effectively reduced, the high degree of centrifugation caused by the rotation of the large-size bearing is reduced, the influences of thermal expansion of different materials caused by temperature on the axial clearance and radial clearance of the end faces of the pump body are reduced, and the efficiency and stability of the electronic oil pump are improved.

[0017] In some implementation solutions, the electronic oil pump further comprises an eccentricity calibration element located between the fixed shaft and the internal gear, the eccentricity calibration element is a half-moon sleeve disposed on the circumferential outer wall of the fixed shaft, the half-moon sleeve is provided with an arc groove into which the fixed shaft can be inserted, and the half-moon sleeve is configured to allow the internal gear to be eccentrically and rotatably connected to the fixed shaft. Preferably, the half-moon sleeve is fixedly connected to the pump arch.

[0018] By adopting the above technical solution, the eccentricity calibration member can compensate for the concentricity deviation caused by the machining and assembly of a plurality of parts such as the pump arch, the fixed shaft and the motor, thereby effectively ensuring the concentricity of the pump arch, the fixed shaft and the motor. When the outer gear is rotatably connected to the fixed shaft, in parallel, the eccentric integrated body can be rotatably connected to the inner gear, thus providing the effect that the inner gear and outer gear are coaxial and eccentric. Meanwhile, due to the fixed shaft being arranged concentrically with respect to the pump arch, the motor rotor can realize, with the help of the fixed shaft, high concentricity of the fixed shaft and the pump arch, which can effectively compensate for the problem of low concentricity accuracy caused by the accumulation of tolerances during machining and assembly.The circumferential side wall of the fixed shaft is partially inserted into the arc groove, so that the circumferential side wall of the fixed shaft and the circumferential outer wall of the half-moon sleeve form an eccentric integrated body rotatably connected to the inner gear, thereby providing the effect that the inner gear and the outer gear are coaxial and eccentric, realizing the effect of coaxiality and eccentricity between the inner gear and the outer gear, effectively compensating for the problem of low eccentricity accuracy of the center and axial center of the motor caused by the accumulation of tolerances during machining and assembly, and also ensuring the mutual drive between the inner gear and the outer gear of the rotor pump based on the centrifugal design.

[0019] In some implementation solutions, a shaft sleeve is also provided, and the inner gear is rotatably connected to the half-moon sleeve and the fixed shaft via 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 sliding resistance and improve the rotation efficiency.

[0021] In some implementation solutions, the fixed shaft or external gear is fixedly connected to a sensor for cold start

[0022] In some implementation solutions, the outer gear and the inner gear enclose to form a plurality of oil loading-unloading cavities, the volume of the oil loading-unloading cavity increases stage by stage according to the rotation direction of the outer gear, then decreases stage by stage, the pump arch is provided with an oil inlet hole and an oil outlet hole, when the volume of the oil loading-unloading cavity increases stage by stage, the oil inlet port of the oil loading-unloading cavity corresponds to the oil inlet hole, and when the volume of the oil loading-unloading cavity decreases stage by stage, the oil outlet port of the oil loading-unloading cavity corresponds to the oil outlet hole.

[0023] In some implementation solutions, when the volume of the oil loading-unloading cavity increases stage by stage, the cooling oil enters the oil loading-unloading cavity through the oil inlet hole, and when the volume of the oil loading-unloading cavity reduces stage by stage, the cooling oil contained in the oil loading-unloading cavity is pressurized and is discharged through the oil outlet hole.

[0024] By adopting the above technical solution, the circumferential inner wall of the outer gear inner circle, the inner end face of the outer circle of the outer gear and the circumferential outer wall of the inner gear enclose each other to form a plurality of oil loading-unloading cavities which are closed. When the inner gear and the outer gear rotate relatively to each other, the oil loading-unloading cavity, as its volume increases stage by stage, is charged with oil through the oil inlet hole, the amount of oil in the oil loading-unloading cavity increases with the volume, and the low-temperature oil contacts the teeth of the inner gear and the outer gear during loading and thus absorbs the heat of the teeth.The oil loading-unloading cavity, when its volume decreases stage by stage, is discharged with oil through the oil outlet hole, the amount of oil in the oil loading-unloading cavity decreases with the volume, the high temperature oil which absorbed heat during loading is discharged from the pump body through the oil outlet hole, thereby realizing cooling and lubrication of the inner gear and outer gear and cooling of the pump body, and ensuring the working temperature and efficiency of the pump.

[0025] In some implementation solutions, an electrical circuit control module may also be provided, the electrical circuit control module comprises a controller and a wire collector arranged in the pump arch, the motor stator is arranged on the wire collector, the motor stator is provided, along its own circumference, with a plurality of stator windings, the motor rotor is sleeved on the circumferential outer circle of the outer gear and the circumferential outer wall of the motor rotor corresponds to the circumferential inner wall of the motor stator.

[0026] By adopting the above technical solution, the controller controls the wire collector to energize the plurality of stator windings on the motor stator, once energized, the plurality of stator windings generate the magnetic field, such 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 on the outer rotor of the gear pump, that is, the motor stator and the rotor magnet interact to drive the outer gear of the rotor gear pump to rotate, and the outer gear of the rotor gear pump rotor gears therefore cause the inner gear to rotate, thus achieving relative rotation between the inner gear and the outer gear.

[0027] In certain implementation solutions, the periphery of the pump arch is further provided with an O-shaped O-ring.

[0028] In said technical solution, the O-ring is deformable in the horizontal and axial directions, which is advantageous for sealing, reducing the risk of oil leakage and generating high pressure, with economy, ease of assembly, long service life and ease of maintenance.

[0029] From all of the above, the present application achieves at least one of the following technical benefits:

[0030] 1. The height of the electronic oil pump of the present application is reduced, The system volume is reduced, the system weight is reduced, and the costs are reduced. The structure is simple, the assembly accuracy is high, the operating efficiency is high, and the product life is extended.

[0031] 2. In certain solutions for implementing the present application, the pump The electronic oil pump has a small aspect ratio, the pump body structure is more stable, and the concentricity of the motor, pump gear, and rotating shaft can be effectively improved. This design can greatly reduce the assembly difficulty of the gear pump structure, rotating shaft, and pump body housing, thereby ensuring the concentricity of the pump body system structure and improving the accuracy of the air clearance between the motor stator and the motor rotor. In this way, the motor operation is always in a magnetic field with precise and uniform distribution, the motor operation is more stable and accurate, the motor uses the magnetic field more effectively, and finally the high-efficiency operation of the electronic oil pump is ensured.

[0032] 3. By using the second bearing, the size of the bearing being reduced, the surface the large contact interface between the bearing and the outer gear of the gear pump and the pump body casing is reduced, the assembly accumulated gap caused by multiple contact interfaces is reduced, the sliding resistance generated by the rotation of the pump body structure is effectively reduced, the high degree of centrifugation caused by the rotation of the large bearing is reduced, and the efficiency and stability of the electronic oil pump are improved.

[0033] 4. By arranging the second bearing, the lower part of the rotating shaft is integrally fixed to the pump body, and the upper part of the rotating shaft is directly connected to the upper cover of the outer gear, which accurately ensures the end face clearance and radial clearance of the pump body, and avoids the thermal expansion effect caused by the temperature variation caused by the temperature coefficient of different part materials. In addition, by arranging the second bearing, the structure of the electronic pump is more stable, which effectively reduces the vibration and noise of the pump body during operation, improves the NVH performance of the pump body, improves the reliability of the pump body and extends the service life of the pump body. DESCRIPTION OF FIGURES

[0034] [Fig. 1] is a diagram of the appearance structure according to the first embodiment of the electronic oil pump of the present application;

[0035] [Fig.2] is a three-dimensional sectional diagram of the structure according to the first mode of realization of the electronic oil pump of the present application;

[0036] [Fig.3] is a diagram of the internal structure according to the first embodiment of the electronic oil pump of the present application;

[0037] [Fig.4] is a diagram of the structure of the motor stator according to the first mode of production of the electronic oil pump of the present application;

[0038] [Fig.5] is a diagram of the structure of the pump arch according to the first mode of production of the electronic oil pump of the present application;

[0039] [Fig.6] is a three-dimensional sectional diagram according to the second mode of production of the electronic oil pump of the present application;

[0040] [Fig.7] is a diagram of the structure of the electrical circuit control module, of the outer gear and the inner gear according to the second embodiment of the electronic oil pump of the present application;

[0041] [Fig.8] is a diagram illustrating the adaptation between the motor stator, the gear inner and outer gear according to the second embodiment of the electronic oil pump of the present application;

[0042] [Fig.9] is a diagram of the structure of the bottom of the pump arch according to the second embodiment of the electronic oil pump of the present application;

[0043] [Fig. 10] is a diagram of the structure of the outer gear and the gear interior according to the second embodiment of the present application;

[0044] [Fig. 11] is a diagram of the structure of the eccentricity calibration element according to the second embodiment of the electronic oil pump of the present application;

[0045] [Fig. 12] is a three-dimensional sectional diagram according to the third mode of realization of the electronic oil pump of the present application.

[0046] In the figures, the reference signs are as follows: 1 - Pump arch; 11 - Oil inlet hole; 12 - Oil outlet hole; 13 - Pump arch bottom; 131 - Fixing hole; 132 - Oil loading port; 133 - Oil discharge port; 134 - Separation portion; 135 - Assembly guide hole; 14 - Filter grid; 15 - Housing; 16 - Air gap; 17 - O-ring; 2 - Outer gear; 21 - Oil loading-unloading cavity; 22 - Motor rotor neck; 23 - Outer gear inner circle; 24 - Motor rotor outer circle; 25 - Top cover; 26 - Sensor; 3 - Inner gear; 4 - Fixed shaft; 41 - Eccentric integrated body; 5 - Eccentricity calibration element; 51 - Arc groove; 52 - Positioning hole; 6 - Bearing; 7 - Shaft sleeve; 8 - Motor rotor; 9 - Electrical circuit control module; 91 - Controller; 92 - Wire collector; 93 - Motor stator; 94 - Stator winding. DETAILED DESCRIPTION OF THE INVENTION

[0047] The object, the technical solution and the advantages of the embodiments of the present invention will become more clearly apparent from the following detailed description with reference to the accompanying figures. The components of the embodiments of the present invention described and illustrated in the accompanying figures may be arranged and designed in different configurations. Other embodiments based on the embodiments of the present invention and obtained by those skilled in the art without creative work should be included within the scope of the present invention.

[0048] It should be noted that similar reference signs and letters indicate similar elements in the accompanying figures below, therefore, once an element is defined in one figure, it is not necessarily defined and explained in more detail in subsequent figures.

[0049] In describing the present invention, it should be noted that, unless otherwise clearly indicated or specified, the terms "mounting", "connecting one to the other", and "connecting" should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection via an intermediate means, and it may be an internal communication between two components. For those skilled in the art, the above terms may be understood according to the specific situations in the embodiments of the present invention.

[0050] It should be understood that in the description of the present application, the terms describing the positionings or positional relationships such as "above", "below", "left" and "right" are based on the positionings or positional relationships shown in the figures, they are only for ease of description of the present application and for simple description, instead of indicating or implying the positions of the devices or elements and the installations and operations in the specified directions, and therefore cannot be understood as restrictions of the present application.

[0051] The embodiment of the present invention can be described in more detail below with reference to the following figures: It should be noted that the features of the following embodiments can be combined with each other unless otherwise indicated. Embodiment I

[0052] Referring to Figures 1 to 5, the present embodiment discloses an electronic oil pump. Referring to [Fig.l], the electronic oil pump comprises a pump arch 1. In some implementation solutions, the pump arch 1 is made of aluminum. The side wall of the pump arch 1 is provided with an oil outlet hole 12, the bottom of the pump arch 1 is provided with an oil inlet hole 11, and the bottom of the pump arch 1 is provided with a filter grid 14 which is positioned at the oil inlet hole 11 and covers the oil inlet hole 11.

[0053] Referring to Figures 2 to 4, a fixed shaft 4, a motor, an electrical circuit control module 9 and a gear set are mounted in the pump arch 1. The motor comprises a motor rotor 8, a motor stator 93 and stator windings 94. The motor stator 93 is fixed in the pump arch 1, the motor rotor 8 is arranged in the motor stator 93, the stator windings 94 are arranged in several groups, which are distributed in a circular array and wound on the motor stator 93, located between the motor rotor 8 and the motor stator 93.

[0054] The gear set comprises an outer gear 2 integrated and fixed to the motor rotor 8 and an inner gear 3 located in the outer gear 2 and meshed with the inner teeth of the outer gear 2. The inner gear 3 is eccentrically and rotatably connected to the fixed shaft 4, the term "eccentric" meaning that the axes of rotation do not coincide. The outer gear 2 is coaxially connected to the fixed shaft 4 and is rotatably connected in the pump arch 1. The outer gear 2 of the present invention is integrated into the motor rotor 8 to form a one-piece assembly by pressing.This design can on the one hand significantly reduce the volume and weight of the system and greatly reduce the material and production costs of the system; and on the other hand effectively reduce the friction at the cavity body of the rotor pump and promote the improvement of the efficiency of the system.

[0055] The pump arch 1 is provided with a casing 15 for separating the controller 91 and the wire collector 92, in order to separate the oil circuit and the electrical control part, to improve the sealing and to ensure the operation of the controller 91 at a suitable temperature. The casing 15 is equipped with a PTC temperature sensor (not marked in the figure) for detecting and indicating the oil temperature cooling, and the PTC temperature sensor is electrically connected to the controller 91. In some implementation solutions, the PTC temperature sensor can realize oil temperature detection with an accuracy of up to 0.1°C.

[0056] Due to the external gear being integrated in the motor rotor, the thermal expansion coefficient of the motor stator 93 is the same as that of the pump body, which greatly reduces the influences of temperature on the clearance of the oil pump, accurately guarantees the clearance of the pump end face, effectively reduces or avoids the influences of temperature on the flow efficiency of the system.

[0057] In the operation process, the electrical circuit control module 9 controls the plurality of stator windings 94 to be energized, then a magnetic field is generated, and the generated magnetic field and the permanent magnetic field of the motor rotor magnet 8 interact to drive the motor rotor 8 to rotate. The motor rotor 8 is fixed relative to the outer gear 2, that is, the motor stator 93 and the motor rotor magnet 8 interact to drive the outer gear 2 to rotate, and the outer gear 2 thus drives the inner gear 3 to rotate, thereby realizing relative rotation between the inner gear 3 and the outer gear 2.

[0058] In particular, projection surfaces of the motor stator 93, the motor rotor 8, the outer gear 2, the inner gear 3 and the fixed shaft 4 at least partially coincide in a plane passing through the axial center of the fixed shaft 4. This structure can reduce the axial height of the electronic oil pump, and makes the structure compact and the volume reduced.

[0059] The periphery of the pump arch 1 is further provided with an O-ring. In some implementation solutions, the O-ring is an O-ring 17 made of rubber. The O-ring 17 is used for horizontal and axial deformations, which is advantageous for sealing, reducing the risk of oil leakage and generating high pressure, with economy, high efficiency, ease of assembly, long service life and ease of maintenance.

[0060] In some implementation solutions, the electronic oil pump further comprises an upper cover 25 fixedly connected to the outer gear 2, one end of the fixed shaft 4 is rotatably connected to the pump arch 1 via the bearing 6 and the other end of the fixed shaft 4 is coaxially and fixedly connected to the outer gear 2 via the upper cover 25. The inner gear 3 is off-axis connected to the fixed shaft 4 via the pump arch 1, and the inner gear 3 is rotatably connected to the pump arch 1.

[0061] For cold starting of the high-power electronic oil pump, in the present embodiment, a sensor 26 is fixedly connected to the top of the fixed shaft 4, for example a magnetic transformer. In other implementation solutions, the sensor 26 can also be fixedly connected to the upper cover 25 fixedly connected to the outer gear 2.

[0062] The electrical circuit control module 9 comprises a wire collector 92 arranged in the pump arch 1 and located above the motor, and a controller 91 located above the wire collector 92. The function of the wire collector 92 is to collect the incoming and outgoing wires of the stator windings 94, so that the distribution of the wire heads is regular and clear and the wire heads are welded onto the wire collector 92 by a simple and clear method. Another function of the wire collector 92 is to separate the controller 91 and the motor part, so that the oil circulates only in the motor part and forms a cooling and lubricating circuit and no oil enters the controller 91.

[0063] A wire collector 92 is provided above the stator component. Pins of the stator winding 94 pass through the wire collector 92, which simplifies the design of electronic control components and simplifies the traditional winding structure.

[0064] The controller 91 can realize fast response and has the properties such as protection against reverse connection of electric circuits, protection against signal interference, monitoring of oil temperature, overheating protection, provision of independent communication channel, detection of angular position of motor, reception and calculation of motor speed and comparison and adjustment of actual rotor speed.

[0065] Since the height of the entire electronic oil pump is reduced compared with the traditional electronic oil pump, in the present embodiment, the passage time of the pressurized cooling oil to the stator component is short and the cooling effect is improved.

[0066] Referring to [Fig.2], a process of the electronic oil pump: the controller 91 controls the wire collector 92 to energize the plurality of stator windings 94 on the motor stator 93, once energized, the plurality of stator windings 94 generates the magnetic field to drive the motor rotor 8 to rotate, and the motor stator 93 drives the outer gear 2 to rotate, thereby realizing relative rotation between the inner gear 2 and the outer gear 3.

[0067] When the inner gear 3 and the outer gear 2 rotate relatively to each other, the oil loading-unloading cavity 21, as its volume increases stage by stage, is charged with oil through the inlet hole oil 11, the amount of oil in the oil loading-unloading cavity 21 increases with the volume. In this case, the low-temperature oil during loading comes into contact with the teeth of the inner gear 3 and the outer gear 2 and thus absorbs heat from the teeth. Subsequently, the oil loading-unloading cavity 21, when its volume decreases stage by stage, is discharged with oil through the oil outlet hole 12, the amount of oil in the oil loading-unloading cavity 21 decreases with the volume. In this case, the high-temperature oil which has absorbed heat during loading is discharged from the pump body through the oil outlet hole 12, thereby realizing cooling and lubrication of the inner gear 3 and the outer gear 2 and cooling of the pump body.

[0068] Referring to [Fig.5], the bottom of the pump arch 1 is provided with a pump arch bottom 13 which is integrally formed and covers the oil inlet hole 11 and the oil outlet hole 12. The bottom of the pump arch 1 is provided with a fixing hole 131 and the fixing hole 131 is arranged concentrically with respect to the pump arch 1. The fixed shaft 4 is arranged in the fixing hole 131 and the circumferential outer wall of the fixed shaft 4 fits closely with the hole wall of the fixing hole 131. A sliding bearing is provided between the inner gear 3 and the pump arch 1 to reduce rotational resistance and prolong service life. The end face of the pump arch bottom 13 is provided with an oil charging port 132 in communication with the oil inlet hole 11 and an oil discharging port 133 in communication with the oil outlet hole 12.A separating portion 134 for separating the oil charging port 132 and the oil discharging port 133 is provided at the pump arch bottom 13, and one side of the separating portion 134 bears on one side of the inner gear 3 to improve the sealing between the oil charging port 132 and the oil discharging port 133.

[0069] The embodiment realizes an eccentric fit between the inner gear 3 and the outer gear 2 by arranging the eccentric fixing hole 131 of the pump arch, without additional parts. This design has the following advantages: the structure of the gear pump is simple, the difficulty of assembling the rotating shaft and the pump body casing is reduced; the concentricity between the motor, the casing and the gear set is improved, thereby ensuring the concentricity of the pump body system structure; thereby improving an air clearance between the motor stator and the motor rotor, in this way, the operation of the motor is always in a magnetic field with precise and uniform distribution; the operation of the motor is more stable with high precision, the motor uses the magnetic field more efficiently, and Finally, the high-efficiency operation of the electronic oil pump is ensured; the accumulated assembly gap caused by multiple contact interfaces is reduced, the sliding resistance generated by the rotation of the pump body structure is effectively reduced; the high degree of centrifugation caused by the rotation of the large-size bearing is reduced, and the efficiency and stability of the electronic oil pump are improved; the volume is reduced, the weight is light, and the costs are reduced. Embodiment II

[0070] Referring to Figures 6 to 11, the eccentric connection structure of the fixed shaft 4 of the present embodiment is different from that of Embodiment I.

[0071] Referring to Figures 6 to 8, the outer gear 2 of the present embodiment comprises an outer gear inner circle 23, which is meshed with the inner gear 3, and the motor rotor inner circle is fixedly sleeved to the outer gear outer circle. The motor rotor permanent magnet 8 is fixed to the circumference of the motor rotor outer circle 24, and an air gap 16 is provided between the motor rotor permanent magnet 8 and the stator winding 94. In the development process, it is necessary to minimize the influences of various factors on the distance stability of the air gap 16. The top of the motor rotor outer circle 24 is provided with a motor rotor neck 22 which is integrally formed, and a bearing 6 is mounted in the motor rotor neck 22.The spherical bearing 6 supports the motor rotor 8 to ensure the rotation of the external gear 2 in the rotor pump, and the spherical bearing 6 is mounted at the end of the rotor pump, so that no cavity is provided between the motor and the rotor pump, thereby reducing the height of the electronic oil pump, greatly reducing the weight of the rotor pump and reducing the volume of the rotor pump. In the present embodiment, the spherical bearing 6 and the pump arch 1 are processed with the same mechanical device, so that both have very precise coaxiality and concentricity, and the eccentricity of the air clearance is precisely controlled.

[0072] Referring to Figures 6 to 9, the bottom of the pump arch 1 is provided with a fixing hole 131 and the fixing hole 131 is arranged concentrically with respect to the pump arch 1. A fixed shaft 4 is provided through the fixing hole 131, the fixed shaft 4 fits tightly with the bearing 6 and the motor rotor neck 22 is integrally formed on one side of the outer gear 2 and fits with the bearing 6. The inner gear comprises an inner circle of inner gear which fits coaxially with the fixed shaft 4 and bears against the eccentric integrated body, and the inner gear 3 is eccentrically and rotatably connected to the fixed shaft 4 via the calibration member of eccentricity 5, the term "eccentric" meaning that the axes of rotation do not coincide. The eccentricity calibration member 5 is a half-moon sleeve disposed 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 can be inserted, and the half-moon sleeve is configured to allow the inner gear 3 to be eccentrically and rotatably connected to the fixed shaft 4. The inner circle of the motor rotor is configured to press on the outer circle of the outer gear.A motor rotor neck 22 is integrally formed on one side of the motor rotor outer circle 24 and fits the bearing 6, the motor rotor neck 22 and one side of the motor rotor outer circle 24 form an insertion groove into which the bearing 6 can be inserted, and the circumferential outer wall of the bearing 6 fits closely with the circumferential wall of the insertion groove, thereby reducing operating noise.

[0073] Referring to Figures 9 to 11, the circumferential inner wall of the outer gear inner circle 23 and the circumferential outer wall of the inner gear 3 both bear on the inner end face of the motor rotor outer circle 24, the area between the outer gear 2 and the inner gear 3 is divided by the contact between the teeth to form a plurality of oil loading-unloading cavities 21 which are closed, the volume of the oil loading-unloading cavity 21 increases stage by stage according to the rotation direction of the outer gear 2 and then decreases stage by stage, an oil inlet hole 11 is integrally formed on the bottom of the pump arch 1 and an oil outlet hole 12 is integrally formed on the circumferential outer wall.When the volume of the oil loading-unloading cavity 21 increases stage by stage, the oil inlet port of the oil loading-unloading cavity 21 corresponds to the oil inlet hole 11, and when the volume of the oil loading-unloading cavity 21 decreases stage by stage, the oil outlet port of the oil loading-unloading cavity 21 corresponds to the oil outlet hole 12.

[0074] The bottom of the pump arch 1 is provided with a pump arch bottom 13 which is integrally formed and covers the oil inlet hole 11 and the oil outlet hole 12, the end face of the pump arch bottom 13 is axially provided with a fixing hole 131 fixedly connected to one end of the fixed shaft 4. The fixed shaft 4 is inserted into the fixing hole 131 and the circumferential outer wall of the fixed shaft 4 fits closely with the hole wall of the fixing hole 131, and a sliding bearing is provided between the inner gear 3 and the pump arch 1 to reduce rotational resistance and prolong service life. The end face of the pump arch bottom 13 is provided with a loading port 132 in communication with the oil inlet hole 11 and an oil discharge port 133 in communication with the oil outlet hole 12. A separating portion 134 for separating the oil charging port 132 and the oil discharge port 133 is provided at the pump arch bottom 13, and one side of the separating portion 134 rests on one side of the inner gear 3 to improve the sealing between the oil charging port 132 and the oil discharge port 133.

[0075] A positioning hole 52 is provided on one side of the half-moon sleeve, an assembly guide hole 135 corresponding to the positioning hole 52 is provided at the pump arch bottom 13, the assembly guide hole 135 and the fixing hole 131 are eccentrically arranged, and a shaft sleeve 7 is provided between the fixed shaft 4 and the inner gear 3 to reduce the sliding friction force. The inner gear 3 is rotatably connected to the half-moon sleeve and the fixed shaft 4 via the shaft sleeve 7.

[0076] A hole is provided on the pump arch 1 to fit the fixed shaft 4, thereby effectively reducing the complexity of machining the pump arch 1, increasing the efficiency of machining the pump arch 1, and increasing the fitting accuracy between the outer gear 2 and the inner gear 3.

[0077] The principle of implementing the electronic oil pump with high precision design according to the embodiments of the present application is as follows:

[0078] A single fixed shaft 4 is arranged in the pump arch 1, and then an eccentricity calibration member 5 is arranged on the circumferential side wall of the fixed shaft 4 to form an eccentric integrated body 41, in this way, when the outer gear 2 is rotatably connected to the fixed shaft 4, at the same time, the eccentric integrated body 41 can be rotatably connected to the inner gear 3, thereby providing an effect that the inner gear 3 and the outer gear 2 are coaxial and eccentric. Embodiment III

[0079] Referring to [Fig. 12], the difference between the present embodiment and Embodiment I is that the spherical bearing is arranged between the outer gear and the pump arch and the fixed shaft 4 has a hollow structure. In the present embodiment, a flow channel through which a cooling oil passes is arranged in the fixed shaft 4. According to the present embodiment, the fixed shaft 4 is configured to be statically fixed and the inner gear 3 of the pump rotates relative to the fixed shaft 4 under the drive of the outer gear 2, which provides mutual lubrication to reduce friction, reduces the loss of the rotor pump system and effectively improves the rotation stability of the rotor pump.

[0080] The principle of mechanism of cooling the cooling oil on the stator component in the present embodiment is as follows:

[0081] The motor rotor 8 and the outer gear 2 jointly drive the inner gear 3 to rotate to perform pressurization on the cooling oil that enters through the oil inlet hole 11, so that the pressurized cooling oil portion flows to the stator component through the hollow flow channel of the fixed shaft 4 and cools the stator component, and the cooling oil undergoing heat exchange returns to the low-pressure area.

[0082] In addition, the other part of pressurized cooling oil passes through the high pressure zone and is directly discharged through the oil outlet hole 12.

[0083] In the present embodiment, the fixed shaft 4 is also equipped with a radial magnetic steel for monitoring its position.

[0084] A specific process of cooling on the stator component of the present invention is as follows:

[0085] (1) First, the system is connected to a power source, the controller 91 is powered on, the controller 91 converts electricity into three-phase electricity to power the stator windings 94, the motor rotor 8 and the outer gear 2 are driven to rotate under the action of electromagnetic force, and under the action of the motor rotor 8 and the outer gear 2 rotating, the cooling oil entering from the oil inlet hole 11 passes through the filter grid 14 and enters the low pressure area;

[0086] (2) The motor rotor 8 and the external gear 2 jointly drive the inner gear 3 to rotate around the fixed shaft 4 to perform pressurization on the cooling oil that enters through the oil inlet hole 11, so that the pressurized cooling oil portion flows to the stator component through the fixed shaft 4 and cools the stator component, and the cooling oil undergoing heat exchange returns to the low pressure area to perform pressurization on the cooling oil under the effect of the centrifugal force generated by the difference between the inner gear and the outer gear. At this time, the PTC temperature sensor detects the current oil temperature value, and sends this temperature value to the controller 91, and the controller 91 sends the current oil temperature value to an external control system;

[0087] (3) The other part of pressurized cooling oil passes through the area of high pressure and is directly discharged through oil outlet hole 12.

[0088] The above description shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art will understand that the present invention is not limited to the above embodiments, and the The above embodiments and description describe only the principles of the present invention. Any changes, modifications, substitutions and variations are permissible and should be included within the scope of the present invention.

Claims

Claims

1. An electronic oil pump, comprising a pump arch (1), characterized in that it further comprises: - a fixed shaft (4), which is arranged in the pump arch (1); - an inner gear (3), which is offset and rotatably connected to the fixed shaft (4); - an outer gear (2), which is coaxially connected to the fixed shaft (4) and is rotatably connected in the pump arch (1), and the outer gear (2) is located at the periphery of the inner gear (3) and meshes with the inner gear (3); - a motor rotor (8), which is fixedly connected to the periphery of the outer gear (2); and - a motor stator (93), which is located at the periphery of the rotor and is fixedly connected to the pump arch (1);wherein, projection 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 coincide in a plane passing through the axial center of the fixed shaft (4).;

2. An electronic oil pump according to claim 1, characterized in that it further comprises a first bearing (6), the outer gear (2) is rotatably connected to one end of the fixed shaft (4) via the first bearing (6), and the other end of the fixed shaft (4) is connected to the pump arch (1).

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

4. An electronic oil pump according to any one of claims 1 to 3, characterized in that it further comprises an eccentricity calibration member (5) located between the fixed shaft (4) and the internal gear (3), the eccentricity calibration member (5) is a half-moon sleeve arranged 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) can be inserted, and the half-moon sleeve is configured to allow the internal gear (3) is eccentrically and rotatably connected to the fixed shaft (4).

5. An electronic oil pump according to claim 4, characterized in that it further comprises a shaft sleeve (7), and the inner gear (3) is rotatably connected to the half-moon sleeve and the fixed shaft (4) via the shaft sleeve (7).

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

7. An electronic oil pump according to any one of claims 1 to 3, characterized in that, the outer gear (2) and the inner gear (3) enclose to form a plurality of oil loading-unloading cavities (21), the volume of the oil loading-unloading cavity (21) increases stage by stage according to the rotation direction of the outer gear (2), then decreases stage by stage, the pump arch (1) is provided with an oil inlet hole (11) and an oil outlet hole (12), when the volume of the oil loading-unloading cavity (21) increases stage by stage, the inlet port of the oil loading-unloading cavity (21) corresponds to the oil inlet hole (11), and when the volume of the oil loading-unloading cavity (21) decreases stage by stage, the oil outlet port of the oil loading-unloading cavity (21) corresponds to the oil outlet hole (12).

8. An electronic oil pump according to claim 7, characterized in that when the volume of the oil loading-unloading cavity (21) increases step by step, the cooling oil enters the oil loading-unloading cavity (21) through the oil inlet hole (11), and when the volume of the oil loading-unloading cavity (21) reduces step by step, the cooling oil contained in the oil loading-unloading cavity (21) is pressurized and is discharged through the oil outlet hole (12).

9. Electronic oil pump according to claim 1, characterized in that it comprises in addition to an electrical circuit control module (9), the electrical circuit control module (9) comprises a controller (91) and a wire collector (92) arranged in the pump arch (1), the motor stator (93) is arranged on the wire collector (92), the motor stator (93) is provided, along its own circumference, with a plurality of stator windings (94), the motor rotor (8) is sleeved on the circumferential outer circle of the outer gear (2), and the circumferential outer wall of the motor rotor (8) matches the circumferential inner wall of the motor stator (93).

10. Electronic oil pump according to claim 9, characterized in that the periphery of the pump arch (1) is further provided with an O-shaped O-ring.

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