Electronic oil pump

Abstract

The utility model discloses an electronic oil pump, which relates to the technical field of motors and electronic oil pumps and comprises a stator assembly, a pump cover component, an oil pump shell component, a power rotor component, a motor rotor component, a rotating shaft, a driving circuit board and a rear end cover. A motor rotor cavity and a circuit board mounting cavity which are isolated from each other are formed in a motor cavity shell of the stator assembly, and a connector shell is also formed in the motor cavity shell; the stator assembly is located at the outer ring of a motor rotor cavity of the motor cavity shell, a stator terminal of the stator assembly extends into a circuit board installation cavity of the motor cavity shell, and a connector terminal of the connector assembly penetrates through the motor cavity shell. The electronic oil pump is high in efficiency, compact in structure, simple in assembly process and high in reliability. According to the electronic oil pump, the power density, the part integration degree and the reliability of the electronic oil pump are improved, and the procedures of press fitting of dry and wet shielding plates, sealing ring assembling and the like are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of motors and electronic oil pumps, in particular to an electronic oil pump. Background Art

[0002] With the development of the automobile industry (especially the new energy automobile industry), automobiles have a higher pursuit of power density. Traditional mechanical oil pumps cannot achieve autonomous speed regulation, resulting in energy waste and low efficiency, and are gradually being eliminated by the market.

[0003] Electronic oil pumps can achieve autonomous speed regulation, thereby being able to supply flow on demand, achieving higher overall efficiency and power density, and improving energy conservation and emission reduction effects. Therefore, the market share of electronic oil pumps is increasing.

[0004] Electronic oil pumps in the prior art can be divided into two categories according to their dry and wet characteristics, namely dry electronic oil pumps and wet electronic oil pumps.

[0005] The Chinese utility model patent publication with publication number CN111664089A and title “Electronic Oil Pump” discloses a typical dry electronic oil pump structure. However, the dry electronic oil pump in the prior art faces two technical problems: 1. Reliability of the oil seal structure: The oil seal of the dry electronic oil pump is very sensitive to factors such as the cleanliness of the use environment and the coaxiality during assembly. Any slight error will cause problems such as reduced performance and service life of the oil seal; 2. Power density problem: The stator assembly of the dry electronic oil pump is completely cooled by air cooling of the pump casing, so that the stator assembly can only adapt to lower current density. At the same power, the volume of the dry electronic oil pump is larger than that of the wet electronic oil pump.

[0006] The pump chamber and the motor chamber of the wet electronic oil pump are through structures, and its electronic rotor also participates in the oil circulation. The Chinese utility model patent publication with publication number CN118066113A, entitled "An electronic oil pump and electric drive system", and the Chinese utility model patent publication with publication number CN118367705A, entitled "An electronic oil pump with enhanced sealing of electrical connection", both disclose typical wet electronic oil pump structures. Although the wet electronic oil pump can omit the oil seal structure, the driving circuit board and the stator assembly of the wet electronic oil pump need to ensure both stable electrical connection and sealing, so that the wet electronic oil pump has a more complex structure and more parts (for example, usually 3 sealing rings need to be set), which makes the wet electronic oil pump larger in size and more complicated in assembly process. The combination of more parts also reduces the overall reliability of the wet electronic oil pump.

[0007] In summary, how to provide an electronic oil pump with high efficiency, compact structure, simple assembly process and high reliability has become an urgent problem to be solved. Summary of the Invention

[0008] The purpose of the present utility model is to provide an electronic oil pump, which has the characteristics of high efficiency, compact structure, simple assembly process and high reliability.

[0009] To achieve the above object, the utility model provides the following technical solutions: An electronic oil pump, which includes a stator assembly, a pump cover member, an oil pump housing member, a power rotor assembly, a motor rotor assembly, a rotating shaft, a drive circuit board, and a rear end cover; The stator assembly includes a stator component, a motor cavity housing, and a connector assembly; The stator component is provided with at least stator terminals; The connector assembly is provided with at least connector terminals; The motor cavity housing is integrally injection-molded outside the stator component and the connector assembly, so that at least a part of the stator component and the connector assembly is buried in the motor cavity housing; An electrically isolated motor rotor cavity and a circuit board mounting cavity are formed inside the motor cavity housing, and further, a connector housing is formed on the motor cavity housing; The stator component is located at the outer ring of the motor rotor cavity of the motor cavity housing, and the stator terminals of the stator component extend into the circuit board mounting cavity of the motor cavity housing; The connector terminals of the connector assembly penetrate the motor cavity housing, so that one end of the connector terminals extends into the connector housing, and the other end of the connector terminals extends into the circuit board mounting cavity; The pump cover member is respectively formed with an oil inlet and an oil outlet that communicate with its inner and outer sides; Inside the oil pump housing member are formed: a power rotor cavity and a stator assembly mounting cavity that communicate with each other through a communication hole, and a middle bearing chamber that communicates the power rotor cavity and the stator assembly mounting cavity; The power rotor assembly is adapted to receive rotational power and drive the flow of oil; The motor rotor assembly is adapted to magnetically couple with the magnetic field generated by the stator component to generate rotational power; The drive circuit board is fixed in the circuit board mounting cavity of the stator assembly, and the drive circuit board is electrically connected to the stator terminals of the stator component and the connector terminals of the connector assembly respectively; The assembly of the stator assembly and the drive circuit board is installed in the stator assembly mounting cavity of the oil pump housing member, and the rear end cover is fixed at the open end of the stator assembly mounting cavity of the oil pump housing member to shield the circuit board mounting cavity of the stator assembly, the drive circuit board, and the stator assembly mounting cavity of the oil pump housing member; The pump cover member is fixed at the open end of the power rotor cavity of the oil pump housing member; The rotating shaft is supported in the middle bearing chamber of the stator assembly mounting cavity and penetrates the power rotor cavity of the oil pump housing member and the motor rotor cavity of the stator assembly; The motor rotor assembly is sleeved on the rotating shaft and accommodated in the motor rotor cavity of the stator assembly, and the motor rotor assembly and the stator component of the stator assembly are radially aligned with each other; The power rotor assembly is sleeved on the rotating shaft and accommodated in the power rotor cavity of the oil pump housing member;The driving circuit board can drive the stator assembly of the stator components to operate. When the stator components operate, they can magnetically couple and drive the motor rotor assembly to rotate in the motor rotor chamber of the stator assembly, enabling the motor rotor assembly to transmit rotational power to the power rotor assembly through the rotating shaft. When the power rotor assembly rotates, it can drive the oil to enter the power rotor chamber of the oil pump housing component from the oil inlet of the pump cover component, and after providing pressure to the oil, discharge it from the oil outlet of the pump cover component. The oil in the power rotor chamber of the oil pump housing component can enter and exit the stator assembly installation chamber of the oil pump housing component via the communication hole and the gap between the middle bearing chamber and the rotating shaft, and then reach the motor rotor chamber of the stator assembly. The motor rotor assembly includes a rotor core, a plurality of permanent magnets inserted into the rotor core according to polarity, and a motor rotor plastic coating covering at least a part of the surface of the rotor core. The rotor core of the motor rotor assembly forms an avoidance cavity at one end close to the middle bearing chamber of the oil pump housing component. The middle bearing chamber of the oil pump housing component can enter the avoidance cavity of the motor rotor assembly.;

[0010] In the above technical solution, the stator assembly includes a stator core, a coil, an insulating bracket, and the stator terminals. The stator core includes an annular yoke portion, a plurality of tooth portions formed at the inner ring of the yoke portion, and a boot portion formed at the free end of the tooth portions. The insulating bracket is sleeved on the surface of the stator core. The outer ring surface of the yoke portion of the stator core is exposed outside the insulating bracket, and the inner end surface of the boot portion of the stator core is also exposed outside the insulating bracket. The stator terminals are fixed on the insulating bracket. The coil is wound around the tooth portions of the stator core, and the ends of the coil are electrically connected to the stator terminals according to polarity.

[0011] In the above technical solution, the motor cavity housing is provided with a concave structure at the exposed positions of the stator terminals and the connector terminals, and the concave structure is sealed by potting.

[0012] In the above technical solution, the outer ring surface of the yoke portion of the stator core is exposed outside the motor cavity housing, and the inner end surface of the boot portion of the stator core is also exposed outside the motor cavity housing.

[0013] In the above technical solution, the stator assembly of the present invention further includes a stator assembly sealing ring. The motor cavity housing extends along the radial direction at the bottom of the yoke portion of the stator core to form a sealing step. The stator assembly sealing ring is sleeved at the sealing step of the motor cavity housing.

[0014] In the above technical solution, the connector assembly includes a connector bracket and the connector terminals, and the connector terminals are fixed on the connector bracket; after the motor cavity housing is formed, the connector bracket of the connector assembly is embedded in the motor cavity housing.

[0015] In the above technical solution, sealing island structures are provided on the outer sides of the oil inlet and the oil outlet of the pump cover member; an oil inlet distribution cavity is formed inside the oil inlet of the pump cover member; an early oil discharge cavity is formed inside the oil outlet of the pump cover member; an upper bearing chamber is formed inside the pump cover member, and the end of the rotating shaft is supported by the upper bearing chamber of the pump cover member; an upper oil inlet groove is formed at the upper bearing chamber of the pump cover member to supply oil into the upper bearing chamber, and an oil film is formed at the gap between the upper bearing chamber and the rotating shaft.

[0016] In the above technical solution, the power rotor assembly includes an inner rotor and an outer rotor that form a cycloidal gear rotor structure, and the number of teeth of the inner rotor is one less than that of the outer rotor; the inner rotor of the power rotor assembly is sleeved on the rotating shaft and is in interference fit with the rotating shaft; an outward expansion structure is formed at the end of the inner hole of the inner rotor.

[0017] In the above technical solution, the motor rotor plastic coating covers the end face and the surface of the avoidance cavity of the rotor core, so that the side surface of the rotor core is an exposed structure.

[0018] In the above technical solution, a position sensor is mounted on the drive circuit board; at one end of the rotating shaft located in the motor rotor chamber of the stator assembly, an induction magnetic ring matching the position sensor of the drive circuit board is provided; and a shielding sleeve is also provided on the rotating shaft to prevent the rotating shaft from causing magnetic field interference to the induction magnetic ring.

[0019] Compared with the prior art, the beneficial effects of the present utility model are as follows: For the electric oil pump of the present utility model, the motor chamber housing is integrally injection-molded outside the stator assembly and the connector assembly, so that at least a part of the stator assembly and the connector assembly are buried in the motor chamber housing, thereby forming an integrated structure of the stator assembly, the connector assembly and the motor rotor chamber of the electric oil pump, that is, the stator assembly integrates the stator assembly and the connector assembly; the electric oil pump is exempt from configuring an independent dry-wet shielding plate and a connector, and further exempt from setting the sealing structure of the dry-wet shielding plate and the connector, improving the power density, component integration degree and reliability of the electric oil pump, reducing the volume and weight of the electric oil pump, and also reducing the processes such as the press-fitting of the dry-wet shielding plate and the assembly of multiple sealing rings; in addition, integrating the stator assembly into the stator assembly can improve the mechanical strength of the stator assembly, especially making the coils and stator terminals of the stator assembly not shift, fall off and short-circuit due to vibration / collision; the rotor core forms an avoidance cavity, on the one hand, reducing the total weight of the rotor core, thereby reducing the moment of inertia of the motor rotor assembly, which is beneficial to the control of the motor rotor assembly, and on the other hand, the middle bearing chamber of the oil pump housing component can enter the avoidance cavity, making the overall structure of the electric oil pump more compact, with a lower axial length and a smaller volume; at least a part of the surface (end face and avoidance cavity) of the rotor core is provided with a plastic coating for the motor rotor. Compared with dotting and fixing, the reliability of the plastic coating process is higher. The plastic coating for the motor rotor only covers the end face and the surface of the avoidance cavity of the rotor core, making the side surface of the rotor core an exposed structure, which will not cause the outer diameter of the motor rotor assembly to expand, and thus does not occupy the motor air gap. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 One of the three-dimensional views of the stator assembly in the present utility model.

[0021] Figure 2 Another three-dimensional view of the stator assembly in the present utility model.

[0022] Figure 3 The cross-sectional structure view of the stator assembly in the present utility model.

[0023] Figure 4 The structure view of the stator assembly in the present utility model.

[0024] Figure 5 The mating structure view of the stator core and the insulating bracket in the present utility model.

[0025] Figure 6 The structure view of the connector assembly in the present utility model.

[0026] Figure 7 The three-dimensional view of the electric oil pump in the present utility model.

[0027] Figure 8 One of the exploded views of the electric oil pump in the present utility model.

[0028] Figure 9 Another exploded view of the electric oil pump in the present utility model.

[0029] Figure 10 A cross-sectional view of the electric oil pump in the present utility model.

[0030] Reference numerals are: 1, stator assembly; 11, stator component; 111, stator core; 1111, yoke portion; 1112, tooth portion; 1113, boot portion; 112, insulating bracket; 113, coil; 114, stator terminal; 12, motor cavity housing; 121, motor rotor chamber; 1211, avoidance recess; 122, circuit board mounting cavity; 123, connector housing; 124, sealing step; 125, recess structure; 13, connector assembly; 131, connector terminal; 132, connector bracket; 14, stator assembly sealing ring; 2, pump cover member; 21, oil inlet; 211, oil inlet distribution cavity; 22, oil outlet; 221, early oil discharge cavity; 23, sealing island structure; 24, upper bearing chamber; 241, upper oil inlet groove; 3, oil pump housing member; 31, power rotor chamber; 32, stator assembly mounting cavity; 33, middle bearing chamber; 331, middle oil inlet groove; 34, communication hole; 4, power rotor assembly; 41, inner rotor; 411, outward expansion structure; 42, outer rotor; 5, motor rotor assembly; 51, rotor core; 511, avoidance cavity; 52, permanent magnet; 53, motor rotor plastic coating; 6, rotating shaft; 61, induction magnetic ring; 62, shielding sleeve; 7, drive circuit board; 8, rear end cover. Specific embodiments

[0031] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. 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.

[0032] This embodiment provides an electric oil pump that can be used to drive the flow of oil.

[0033] Please refer to Figures 7 - 10 , the electric oil pump of this embodiment includes a stator assembly 1, a pump cover member 2, an oil pump housing member 3, a power rotor assembly 4, a motor rotor assembly 5, a rotating shaft 6, a drive circuit board 7, and a rear end cover 8.

[0034] Among them, the pump cover member 2 is an integrally formed metal cover member, which can be obtained by integral die-casting or machining; the oil pump housing member 3 is an integrally formed metal housing member, which can be obtained by integral die-casting or machining. The surface of the oil pump housing member 3 is provided with mounting arms for mounting and fixing the electric oil pump. Moreover, a sealing ring is sleeved on the surface of the oil pump housing member 3 to enhance the sealing degree between the electric oil pump and the external structure; the rotating shaft 6 is an integrally formed metal shaft body, whose outer contour is generally cylindrical, and it can be a solid shaft or a hollow shaft, which can be obtained by integral die-casting or machining; the drive circuit board 7 is a printed circuit board (PCB), which is equipped with a main control, a stator drive module (chip) for driving the stator assembly 11 to operate, and other necessary peripheral circuits; the rear end cover 8 is an integrally formed metal cover member, which can be obtained by integral die-casting or machining.

[0035] Please refer to Figures 1 - 6 , the stator assembly 1 of this embodiment includes a stator assembly 11, a motor chamber housing 12, and a connector assembly 13.

[0036] Among them, the stator assembly 11 is a combination body, which is used to generate a magnetic field to magnetically couple and drive the rotation of the rotor assembly; the connector assembly 13 is also a combination body, which is used to realize the connection between the drive circuit board 7 of the electric oil pump and an external power source and / or signal source.

[0037] The stator assembly 11 is at least provided with stator terminals 114. In this embodiment, the stator terminals 114 are copper terminals and several of them are provided; the connector assembly 13 is at least provided with connector terminals 131. In this embodiment, the connector terminals 131 are copper terminals and several of them are provided.

[0038] The motor chamber housing 12 is integrally injection-molded outside the stator assembly 11 and the connector assembly 13, so that at least a part of the stator assembly 11 and the connector assembly 13 is buried in the motor chamber housing 12.

[0039] An electrically isolated motor rotor chamber 121 and a circuit board mounting cavity 122 are formed inside the motor chamber housing 12. Moreover, the motor chamber housing 12 also forms a connector housing 123; specifically, a transverse partition structure is formed inside the motor chamber housing 12, and this partition structure isolates the inner cavity of the motor chamber housing 12 into two parts, one part is the motor rotor chamber 121, and the other part is the circuit board mounting cavity 122; the connector housing 123 is used to be plugged and matched with an external connector to form a complete connector housing 123 structure, and it can be arranged on the side surface of the motor chamber housing 12 or on the end surface of the motor chamber housing 12. In this embodiment, the connector housing 123 is arranged on the side surface of the motor chamber housing 12.

[0040] The stator assembly 11 is located at the outer ring of the motor rotor chamber 121 of the motor chamber housing 12, and the stator terminals 114 of the stator assembly 11 extend into the circuit board mounting chamber 122 of the motor chamber housing 12; the connector terminals 131 of the connector assembly 13 penetrate through the motor chamber housing 12, so that one end of the connector terminals 131 extends into the connector housing 123, and the other end of the connector terminals 131 extends into the circuit board mounting chamber 122.

[0041] Please refer to Figures 3 - 5 , the stator assembly 11 includes a stator core 111, a coil 113, an insulating bracket 112, and stator terminals 114; wherein, the stator core 111 is a solid body formed by laminating and fixing a plurality of silicon steel sheets, the coil 113 is formed by winding an enameled wire for a certain number of turns, the insulating bracket 112 is a thin sleeve made of engineering plastic, and the stator terminals 114 are generally sheet-shaped copper terminals; the stator core 111 includes an annular yoke portion 1111, a plurality of tooth portions 1112 formed at the inner ring of the yoke portion 1111, and a boot portion 1113 formed at the free end of the tooth portion 1112. In fact, the yoke portion 1111, the tooth portion 1112, and the boot portion 1113 are an integrally formed structure; please refer to Figure 5 , the insulating bracket 112 is sleeved on the surface of the stator core 111. The outer ring surface of the yoke portion 1111 of the stator core 111 is exposed outside the insulating bracket 112, and the inner end surface of the boot portion 1113 of the stator core 111 is also exposed outside the insulating bracket 112 (that is, the insulating bracket 112 mainly covers the tooth portion 1112 of the stator core 111, the inner ring surface of the yoke portion 1111, and the connection side between the boot portion 1113 and the tooth portion 1112); the insulating bracket 112 can be directly formed on the surface of the stator core 111 by an integral injection molding process, or the insulating bracket 112 can be formed separately and then sleeved on the stator core 111; the stator terminals 114 are fixed on the insulating bracket 112. Specifically, the stator terminals 114 are inserted and fixed on the insulating bracket 112, or the insulating bracket 112 is directly formed by an integral injection molding process, and one end of the stator terminals 114 is buried in the insulating bracket 112; the coil 113 is wound on the tooth portion 1112 of the stator core 111, and the ends of the coil 113 are electrically connected to the stator terminals 114 according to the polarity.

[0042] Further, the outer ring surface of the yoke portion 1111 of the stator core 111 is exposed outside the motor housing 12, and the inner end surface of the shoe portion 1113 of the stator core 111 is also exposed outside the motor housing 12; in fact, the overall outer ring of the stator core 111 is the outer ring surface of the yoke portion 1111, and the overall inner ring of the stator core 111 is the inner end surface of the shoe portion 1113. When the motor housing 12 is formed, by only controlling the wall thickness of the motor rotor chamber 121, it can be achieved that the outer ring surface of the yoke portion 1111 of the stator core 111 is exposed outside the motor housing 12, and the inner end surface of the shoe portion 1113 of the stator core 111 is also exposed outside the motor housing 12.

[0043] Further, the stator assembly 1 of this embodiment further includes a stator assembly sealing ring 14, and the stator assembly sealing ring 14 is an annular rubber sealing ring or a silica gel sealing ring; the motor housing 12 extends along the radial direction at the bottom of the yoke portion 1111 of the stator core 111 to form a sealing step 124, that is, the outer diameter of the sealing step 124 is larger than the outer diameter of the yoke portion 1111 of the stator core 111, and the sealing step 124 is integrally injection-molded with the motor housing 12; the stator assembly sealing ring 14 is sleeved at the sealing step 124 of the motor housing 12. In fact, an annular groove is provided on the side surface of the sealing step 124, and the stator assembly sealing ring 14 is sleeved and embedded in the annular groove.

[0044] Further, the connector assembly 13 includes a connector bracket 132 and a connector terminal 131. The connector bracket 132 is a square engineering plastic frame, and the connector terminal 131 is a copper terminal with a bent structure; the connector terminal 131 is fixed on the connector bracket 132 to limit the connector terminal 131. In fact, the connector terminal 131 is inserted and fixed on the connector bracket 132, or the connector bracket 132 is directly formed by an integral injection molding process, and the middle part of the connector terminal 131 is buried in the connector bracket 132; after the motor housing 12 is formed, the connector bracket 132 of the connector assembly 13 is buried in the motor housing 12.

[0045] In some possible embodiments, the motor housing 12 is provided with a recessed structure 125 at the exposed positions of the stator terminal 114 and the connector terminal 131 (that is, the recessed structure 125 is provided at the partition structure). After the motor housing 12 is formed, the recessed structure 125 is subjected to potting sealing treatment, which can further improve the sealing performance and mechanical strength at the exposed positions of the stator terminal 114 and the connector terminal 131.

[0046] When manufacturing the stator assembly 1 of this embodiment, first assemble the stator component 11 and the connector component 13. Then, place the stator component 11 and the connector component 13 as a whole into the forming mold of the motor cavity housing 12, and inject plastic material into the forming mold. After the plastic material solidifies, the motor cavity housing 12 is formed. At this time, the motor cavity housing 12, the stator component 11, and the connector component 13 form an integral structure, so that at least a part of the stator component 11 and the connector component 13 is buried in the motor cavity housing 12.

[0047] An oil inlet 21 and an oil outlet 22 that communicate with the inside and outside of the pump cover member 2 are respectively formed on the pump cover member 2, and both the oil inlet 21 and the oil outlet 22 are integrally formed with the pump cover member 2.

[0048] Inside the oil pump housing member 3, there are formed: a power rotor chamber 31 and a stator assembly installation chamber 32 that communicate with each other through a communication hole 34, and a middle bearing chamber 33 that communicates the power rotor chamber 31 and the stator assembly installation chamber 32. Specifically, a transverse partition structure is formed inside the oil pump housing member 3, and this partition structure divides the inner cavity of the oil pump housing member 3 into two parts. One part is the power rotor chamber 31, and the other part is the stator assembly installation chamber 32. The communication hole 34 is opened at this partition structure and can communicate the power rotor chamber 31 and the stator assembly installation chamber 32. The middle bearing chamber 33 is a cylindrical shaft hole body structure that can be used to support the rotating shaft 6. It is integrally formed at the partition structure of the oil pump housing member 3 and communicates the power rotor chamber 31 and the stator assembly installation chamber 32.

[0049] The power rotor assembly 4 is adapted to receive rotational power and drive the flow of oil.

[0050] The motor rotor assembly 5 is adapted to magnetically couple with the magnetic field generated by the stator component 11 to generate rotational power.

[0051] The drive circuit board 7 is fixed in the circuit board installation cavity 122 of the stator assembly 1. Specifically, it can be fixed by means such as screws, fixed shafts, or snaps. And the drive circuit board 7 is electrically connected to the stator terminals 114 of the stator component 11 and the connector terminals 131 of the connector component 13 respectively. Specifically, the stator terminals 114 and the connector terminals 131 located in the circuit board installation cavity 122 respectively penetrate into the welding holes reserved on the drive circuit board 7 and are welded to the drive circuit board 7, thereby respectively realizing the electrical connection between the stator terminals 114 and the connector terminals 131 and the drive circuit board 7.

[0052] The assembly of the stator assembly 1 and the drive circuit board 7 is installed into the stator assembly installation cavity 32 of the oil pump housing member 3. Specifically, the stator assembly 1 and the oil pump housing member 3 are fixed to each other through a hot sleeve assembly process. In this embodiment, in order to avoid damaging the stator assembly sealing ring 14 due to the high temperature generated by the hot sleeve assembly process, at the position of the oil pump housing member 3 corresponding to the sealing step 124 of the stator assembly 1, it is pre-treated by machining to thin the oil pump housing member 3 to a certain extent. When the stator assembly 1 is press-fitted into the stator assembly installation cavity 32 of the oil pump housing member 3, the outer ring surface of the stator assembly 1 (i.e., the yoke portion 1111 of the stator core 111) will not interfere with the position of the oil pump housing member 3 corresponding to the sealing step 124 of the stator assembly 1. During the hot sleeve assembly, only the position of the oil pump housing member 3 corresponding to the motor rotor chamber 121 of the stator assembly 1 needs to be heated (without heating the position of the oil pump housing member 3 corresponding to the sealing step 124 of the stator assembly 1), so that the high temperature generated by the hot sleeve assembly process will not affect the stator assembly sealing ring 14, ensuring the performance and service life of the stator assembly sealing ring 14 after assembly; the outer ring surface of the yoke portion 1111 of the stator core 111 is exposed outside the motor chamber housing 12, so that the outer ring surface of the stator assembly 1 at the position of the motor rotor chamber 121 is made of metal, which can thus adapt to the hot sleeve assembly process and avoid the problem of using plastic in cooperation with metal (the inner wall of the oil pump housing member 3), preventing loosening due to excessive difference in the expansion coefficients of different materials.

[0053] The rear end cover 8 is fixed to the open end of the stator assembly installation cavity 32 of the oil pump housing member 3 to shield the circuit board installation cavity 122 of the stator assembly 1, the drive circuit board 7, and the stator assembly installation cavity 32 of the oil pump housing member 3. Specifically, the rear end cover 8 is fixed to the open end of the stator assembly installation cavity 32 of the oil pump housing member 3 by screws, and a sealing ring is provided between the rear end cover 8 and the oil pump housing member 3 to improve the sealing degree of the stator assembly installation cavity 32.

[0054] The pump cover member 2 is fixed to the open end of the power rotor chamber 31 of the oil pump housing member 3. Specifically, the pump cover member 2 is fixed to the open end of the power rotor chamber 31 of the oil pump housing member 3 by screws, and a positioning pin group is provided at the open end of the power rotor chamber 31 of the oil pump housing member 3, and a positioning hole group is provided on the inner side of the pump cover member 2. Through the cooperation of the positioning pin group and the positioning hole group, it is ensured that the relative positions of the pump cover member 2 and the oil pump housing member 3 are correct during assembly.

[0055] The rotating shaft 6 is supported in the middle bearing chamber 33 of the stator assembly installation cavity 32 and penetrates through the power rotor chamber 31 of the oil pump housing member 3 and the motor rotor chamber 121 of the stator assembly 1. That is, the middle bearing chamber 33 of the stator assembly installation cavity 32 provides a bearing support function for the rotating shaft 6.

[0056] Five sets of motor rotor assemblies 5 are sleeved on the rotating shaft 6 and accommodated in the motor rotor chamber 121 of the stator assembly 1. The motor rotor assembly 5 and the stator assembly 11 of the stator assembly 1 are aligned with each other in the radial direction.

[0057] The power rotor assembly 4 is sleeved on the rotating shaft 6 and accommodated in the power rotor chamber 31 of the oil pump housing member 3.

[0058] The drive circuit board 7 can drive the operation of the stator assembly 11 of the stator assembly 1. When the stator assembly 11 operates, it can magnetically couple and drive the motor rotor assembly 5 to rotate in the motor rotor chamber 121 of the stator assembly 1, so that the motor rotor assembly 5 can transmit rotational power to the power rotor assembly 4 through the rotating shaft 6.

[0059] When the power rotor assembly 4 rotates, it can drive the oil to enter the power rotor chamber 31 of the oil pump housing member 3 from the oil inlet 21 of the pump cover member 2. After providing pressure to the oil, the oil is discharged from the oil outlet 22 of the pump cover member 2. The oil in the power rotor chamber 31 of the oil pump housing member 3 can enter and exit the stator assembly installation cavity 32 of the oil pump housing member 3 through the communication hole 34 and the gap between the middle bearing chamber 33 and the rotating shaft 6 (the oil also forms an oil film between the middle bearing chamber 33 and the rotating shaft 6 to lubricate the middle bearing chamber 33 and the rotating shaft 6), and then reach the motor rotor chamber 121 of the stator assembly 1.

[0060] In this embodiment, a middle oil inlet groove 331 is formed at the middle bearing chamber 33 of the oil pump housing member 3 to supply oil to enter the middle bearing chamber 33 and form an oil film at the gap between the middle bearing chamber 33 and the rotating shaft 6 to lubricate the middle bearing chamber 33 and the rotating shaft 6. Specifically, the middle oil inlet groove 331 is a groove-shaped structure integrally formed on the side of the middle bearing chamber 33, and its specific cross-sectional shape is not limited. For example, it can be semicircular, square, irregular shape, etc.

[0061] Exposing the inner end surface of the boot part 1113 of the stator core 111 outside the motor cavity housing 12 reduces the air gap between the stator assembly 1 and the motor rotor assembly 5 on the one hand, effectively improving the efficiency of the stator assembly 1 and the motor rotor assembly 5. On the other hand, since the inner end surface of the boot part 1113 of the stator core 111 can directly contact the oil, the stator core 111 and the coil 113 can be cooled by the oil, improving the heat dissipation performance of the stator assembly 1, enabling the coil 113 of the stator assembly 1 to carry a higher current density, and thus improving the power density of the entire electronic oil pump.

[0062] Furthermore, sealing island structures 23 are provided on the outer sides of the oil inlet 21 and the oil outlet 22 of the pump cover member 2. Specifically, the pump cover member 2 forms annular grooves at the outer rings of the oil inlet 21 and the oil outlet 22, and sealing rings are embedded in the annular grooves to form the sealing island structures 23. An oil inlet distribution cavity 211 is formed inside the oil inlet 21 of the pump cover member 2. The oil inlet distribution cavity 211 and the pump cover member 2 are of an integrally formed structure. And relative to the oil inlet 21, the oil inlet distribution cavity 211 is an enlarged cavity structure, and its specific shape is not limited. For example, it can be circular, semi-circular, oval, and irregular shapes, etc. By providing the oil inlet distribution cavity 211, on the one hand, the flow rate of the oil when entering the power rotor chamber 31 can be reduced (the greater the flow rate, the easier it is to generate turbulence and pulsation), so as to reduce the turbulence and pulsation phenomena generated when the oil flows, and improve the efficiency of the oil flow. On the other hand, it can guide the oil to uniformly reach each part of the power rotor assembly 4 and the communication holes 34 of the oil pump housing member 3, so that the oil is uniformly distributed in the power rotor chamber 31 of the oil pump housing member 3 and the motor rotor chamber 121 of the stator assembly 1. An early oil discharge cavity 221 is formed inside the oil outlet 22 of the pump cover member 2. The early oil discharge cavity 221 and the pump cover member 2 are of an integrally formed structure. And relative to the oil outlet 22, the early oil discharge cavity 221 is an enlarged cavity structure, and its specific shape is not limited. For example, it can be circular, semi-circular, oval, and irregular shapes, etc. By providing the early oil discharge cavity 221, the turbulence and pulsation phenomena generated when the oil flows can be reduced, and the efficiency of the oil flow can be improved. An upper bearing chamber 24 is formed inside the pump cover member 2. The end of the rotating shaft 6 is supported by the upper bearing chamber 24 of the pump cover member 2. In this way, the radial yaw of the rotating shaft 6 is avoided. An upper oil inlet groove 241 is formed at the upper bearing chamber 24 of the pump cover member 2 to supply oil to enter the upper bearing chamber 24, and an oil film is formed at the gap between the upper bearing chamber 24 and the rotating shaft 6 to lubricate the upper bearing chamber 24 and the rotating shaft 6. Specifically, the upper oil inlet groove 241 is a groove-shaped structure integrally formed on the side of the upper bearing chamber 24, and its specific cross-sectional shape is not limited. For example, it can be semi-circular, square, and irregular shapes, etc. In addition, the upper oil inlet groove 241 needs to be provided on the side close to the oil outlet 22 to make it easy for the oil to enter the upper oil inlet groove 241.

[0063] Specifically, the power rotor assembly 4 includes an inner rotor 41 and an outer rotor 42 that constitute a cycloidal gear rotor structure. Among them, the inner rotor 41 is a metal gear member with an external tooth structure, and the outer rotor 42 is a metal gear member with an internal tooth structure. The two form a cycloidal gear rotor structure by nesting; the number of teeth of the inner rotor 41 is one less than that of the outer rotor 42 to form two variable cavities, so as to be suitable for driving the flow of hydraulic oil; the inner rotor 41 of the power rotor assembly 4 is sleeved on the rotating shaft 6 and is in interference fit with the rotating shaft 6 (on this basis, key fit or spline fit can also be used); an outward expansion structure 411 is formed at the end of the inner hole of the inner rotor 41 (compared with an ordinary chamfer, the expansion angle of the outward expansion structure 411 is larger). On the one hand, it reduces the friction area between the inner rotor 41 and the bottom of the power rotor chamber 31, thereby reducing the friction torque and improving the overall efficiency of the product. On the other hand, it avoids chipping due to excessive pressure when the inner rotor 41 is assembled with the rotating shaft 6.

[0064] Specifically, the motor rotor assembly 5 includes a rotor core 51, a plurality of permanent magnets 52 inserted into the rotor core 51 according to polarity, and a motor rotor plastic coating layer 53 covering at least a part of the surface of the rotor core 51; among them, the rotor core 51 is a solid body formed by laminating and fixing a plurality of silicon steel sheets, and it has permanent magnet 52 slots for the permanent magnets 52 to be inserted therein. The permanent magnet 52 (also known as "magnetic tile") is a sheet-shaped body with permanent magnetism; each permanent magnet 52 is inserted into the permanent magnet 52 slot of the rotor core 51 according to polarity, and then the assembly of the rotor core 51 and the permanent magnets 52 is placed into the molding die of the motor rotor plastic coating layer 53 as a whole, and plastic material is injected into the molding die. After the plastic material is cured, the motor rotor plastic coating layer 53 is formed. At this time, the rotor core 51, the permanent magnets 52, and the motor rotor plastic coating layer 53 form an integral structure; the rotor core 51 of the motor rotor assembly 5 forms an avoidance cavity 511 at one end close to the middle bearing chamber 33 of the oil pump housing member 3. That is, the avoidance cavity 511 is a circular cavity recessed axially from the rotor core 51. After the avoidance cavity 511 is set, the axial cross-section of the rotor core 51 is roughly in the shape of a "concave". The middle bearing chamber 33 of the oil pump housing member 3 can enter the avoidance cavity 511 of the motor rotor assembly 5 (but they do not contact); with this setting, on the one hand, it reduces the total weight of the rotor core 51, thereby reducing the moment of inertia of the motor rotor assembly 5 and facilitating the control of the motor rotor assembly 5. On the other hand, it makes the overall structure of the electronic oil pump more compact, with a lower axial length and a smaller volume.

[0065] In the motor rotor assembly in the prior art, some fix the permanent magnets by means of dispensing, which has low reliability but can ensure the motor efficiency; some fix the rotor core and the permanent magnets by means of integral injection molding. Although it can ensure the structural reliability of the rotor assembly, it will expand the outer diameter of the rotor assembly, occupy the motor air gap, and thus reduce the motor efficiency.

[0066] Further, the plastic coating layer 53 of the motor rotor covers the end face of the rotor core 51 and the surface of the avoidance cavity 511, making the side surface of the rotor core 51 an exposed structure; for the plastic-coated rotor assembly in the prior art, its plastic coating layer covers the entire rotor core, occupying a certain degree of the air gap of the motor; for the motor rotor assembly 5 of this embodiment, its plastic coating layer 53 of the motor rotor only covers the end face of the rotor core 51 and the surface of the avoidance cavity 511, making the side surface of the rotor core 51 an exposed structure, which will not cause the outer diameter of the motor rotor assembly 5 to expand, thus not occupying the air gap of the motor (i.e., the gap between the outer diameter of the rotor core 51 and the inner diameter of the stator core 111).

[0067] Further, a position sensor (not shown in the figure), such as a Hall sensor, is mounted on the drive circuit board 7; at one end of the rotating shaft 6 located in the motor rotor chamber 121 of the stator assembly 1, an induction magnetic ring 61 (such as a Hall magnetic ring) matching the position sensor of the drive circuit board 7 is provided. In this embodiment, the induction magnetic ring 61 is located on the end face of the rotating shaft 6; moreover, a shielding sleeve 62 is also provided on the rotating shaft 6 to avoid the rotating shaft 6 causing magnetic field interference to the induction magnetic ring 61, thereby reducing the total magnetic field intensity at the position sensor end (if the magnetic field intensity of the induction magnetic ring 61 received at the position sensor end is too low, it will not be able to sense); in this embodiment, through the shielding sleeve 62, while covering one end of the rotating shaft 6 and the induction magnetic ring 61, on the one hand, the installation of the induction magnetic ring 61 is realized, and on the other hand, the magnetic field generated by the rotating shaft 6 can be avoided from affecting the magnetic field generated by the induction magnetic ring 61, thereby avoiding the position sensor of the drive circuit board 7 from being unable to sense the induction magnetic ring 61; in addition, in the motor cavity housing 12 of the stator assembly 1, an avoidance recess 1211 is formed at the bottom of the motor rotor chamber 121 for the induction magnetic ring 61 and the shielding sleeve 62 to penetrate into it. On the one hand, the position of the induction magnetic ring 61 is made closer to the drive circuit board 7, and on the other hand, the redundant space can be effectively utilized, making the overall structure of the electronic oil pump more compact, with a lower axial length and a smaller volume; an electronic oil pump without a configured position sensor cannot achieve closed-loop control, and the minimum speed of its motor is limited to a certain extent (such as 500 rpm); after configuring the position sensor, the electronic oil pump can achieve closed-loop control, enabling the speeds of the motor rotor assembly 5, the rotating shaft 6, and the power rotor assembly 4 to be adjusted lower (such as dozens of revolutions per minute); the oil fluid driven by the electronic oil pump has a viscosity hundreds of times higher at low temperature than at high temperature, so the starting torque of the electronic oil pump at low temperature is very large. If it is started at a higher speed, the starting power of the electronic oil pump will exceed the rated value by several times, making it difficult for the motor to start. When the electronic oil pump starts, reducing the speeds of the motor rotor assembly 5, the rotating shaft 6, and the power rotor assembly 4 can obtain a larger starting torque to smoothly start the electronic oil pump on the premise that the starting power does not exceed the limit / has a low excess.

[0068] When the electric oil pump of this embodiment is in use, through the connector housing 123 and the connector assembly 13 of the stator assembly 1, it cooperates with an external connector to obtain an external power source and / or signal source; the drive circuit board 7 can drive the stator assembly 11 of the stator assembly 1 to operate. When the stator assembly 11 operates, a rotating magnetic field is generated to magnetically couple and drive the motor rotor assembly 5 to rotate in the motor rotor chamber 121 of the stator assembly 1, so that the motor rotor assembly 5 can transmit the rotational power to the power rotor assembly 4 through the rotating shaft 6; when the power rotor assembly 4 with a cycloidal gear rotor structure rotates, two variable volume chambers are generated. When the volumes of the two variable volume chambers change, a pressure difference can be provided for the liquid, thereby driving the oil to enter the power rotor chamber 31 of the oil pump housing member 3 from the oil inlet 21 of the pump cover member 2, and after providing pressure to the oil, discharging it from the oil outlet 22 of the pump cover member 2; the oil in the power rotor chamber 31 of the oil pump housing member 3 can enter and exit the stator assembly installation cavity 32 of the oil pump housing member 3 through the communication hole 34 and the gap between the middle bearing chamber 33 and the rotating shaft 6, and then reach the motor rotor chamber 121 of the stator assembly 1, which can dissipate heat and lubricate the rotating shaft 6, the stator assembly 11, and the motor rotor assembly 5.

[0069] For the electric oil pump of this embodiment, the motor chamber housing 12 is integrally injection-molded outside the stator assembly 11 and the connector assembly 13, so that at least a part of the stator assembly 11 and the connector assembly 13 is buried in the motor chamber housing 12, so that the stator assembly 11, the connector assembly 13, and the motor rotor chamber 121 of the electric oil pump form an integrated structure, that is, the stator assembly 1 integrates the stator assembly 11 and the connector assembly 13; this enables the electric oil pump to be free from configuring an independent dry-wet shielding plate and connector, and thus free from setting the sealing structure of the dry-wet shielding plate and connector, improving the power density, component integration degree, and reliability of the electric oil pump, reducing the volume and weight of the electric oil pump, and also reducing processes such as dry-wet shielding plate pressing and multiple sealing ring assembly; in addition, integrating the stator assembly 11 into the stator assembly 1 can improve the mechanical strength of the stator assembly 1, especially preventing the coil 113 and the stator terminal 114 of the stator assembly 11 from shifting, falling off, and short-circuiting due to vibration / collision.

[0070] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An electronic oil pump, characterized in that: It includes a stator assembly, a pump cover component, an oil pump housing component, a power rotor component, a motor rotor component, a rotating shaft, a drive circuit board and a rear end cover; The stator assembly includes a stator component, a motor cavity housing and a connector component; The stator assembly is at least provided with a stator terminal; The connector assembly is provided with at least a connector terminal; The motor cavity housing is integrally formed outside the stator assembly and the connector assembly by injection molding, so that at least a portion of the stator assembly and the connector assembly are buried in the motor cavity housing; The interior of the motor cavity housing forms a motor rotor chamber and a circuit board installation chamber that are isolated from each other, and the motor cavity housing also forms a connector housing; The stator assembly is located at the outer ring of the motor rotor chamber of the motor cavity housing, and the stator terminal of the stator assembly extends into the circuit board installation cavity of the motor cavity housing; The connector terminal of the connector assembly passes through the motor cavity housing, so that one end of the connector terminal extends into the connector housing, and the other end of the connector terminal extends into the circuit board mounting cavity; The pump cover component is respectively formed with an oil inlet and an oil outlet communicating with the inner and outer sides thereof; The oil pump housing member has formed therein: a power rotor chamber and a stator assembly installation chamber which are communicated with each other through a communication hole, and a middle bearing chamber which communicates with the power rotor chamber and the stator assembly installation chamber; The power rotor assembly is suitable for receiving rotational power and driving the oil to flow; The motor rotor assembly is adapted to be magnetically coupled with the magnetic field generated by the stator assembly to generate rotational power; The driving circuit board is fixed in the circuit board mounting cavity of the stator assembly, and the driving circuit board is electrically connected to the stator terminals of the stator assembly and the connector terminals of the connector assembly respectively; The assembly of the stator assembly and the drive circuit board is installed in the stator assembly installation cavity of the oil pump housing component, and the rear end cover is fixed to the open end of the stator assembly installation cavity of the oil pump housing component to shield the circuit board installation cavity of the stator assembly, the drive circuit board and the stator assembly installation cavity of the oil pump housing component; The pump cover member is fixed to the open end of the power rotor chamber of the oil pump housing member; The rotating shaft is supported in the middle bearing chamber of the stator assembly installation chamber, and passes through the power rotor chamber of the oil pump housing component and the motor rotor chamber of the stator assembly; The motor rotor assembly is sleeved on the rotating shaft and accommodated in the motor rotor chamber of the stator assembly, and the motor rotor assembly and the stator assembly of the stator assembly are aligned with each other in the radial direction; The power rotor assembly is sleeved on the rotating shaft and accommodated in the power rotor chamber of the oil pump housing component; The driving circuit board can drive the stator component of the stator assembly to operate. When the stator component operates, it can drive the motor rotor component to rotate in the motor rotor chamber of the stator assembly through magnetic coupling, so that the motor rotor component can transmit rotational power to the power rotor component through the rotating shaft; When the power rotor assembly rotates, the oil can be driven to enter the power rotor chamber of the oil pump housing member from the oil inlet of the pump cover member, and after providing pressure to the oil, the oil is discharged from the oil outlet of the pump cover member; The oil in the power rotor chamber of the oil pump housing component can enter and exit the stator assembly installation chamber of the oil pump housing component through the communication hole and the gap between the middle bearing chamber and the rotating shaft, and then reach the motor rotor chamber of the stator assembly; The motor rotor assembly includes a rotor core, a plurality of permanent magnets inserted into the rotor core according to polarity, and a motor rotor plastic coating layer covering at least a portion of the surface of the rotor core; The rotor core of the motor rotor assembly forms a relief cavity at one end close to the middle bearing chamber of the oil pump housing component; The middle bearing chamber of the oil pump housing component can enter into the avoidance cavity of the motor rotor assembly.

2. The electronic oil pump according to claim 1, characterized in that: The stator assembly includes a stator core, a coil, an insulating bracket and the stator terminal; The stator core includes a ring-shaped yoke, a plurality of teeth formed at the inner ring of the yoke, and a boot formed at the free end of the teeth; The insulating bracket is sleeved on the surface of the stator core, the outer annular surface of the yoke of the stator core is exposed to the insulating bracket, and the inner end surface of the boot of the stator core is also exposed to the insulating bracket; The stator terminal is fixed on the insulating bracket; The coil is wound on the teeth of the stator core, and the end of the coil is electrically connected to the stator terminal according to polarity.

3. The electronic oil pump according to claim 1 or 2, characterized in that: The motor cavity housing is provided with a concave structure at the exposed parts of the stator terminals and the connector terminals, and the concave structure is sealed by glue filling.

4. The electronic oil pump according to claim 2, characterized in that: The outer annular surface of the yoke of the stator core is exposed to the motor cavity housing, and the inner end surface of the shoe of the stator core is also exposed to the motor cavity housing.

5. The electronic oil pump according to claim 2 or 4, characterized in that: Also includes a stator assembly sealing ring; The motor cavity housing extends radially at the bottom of the yoke of the stator core to form a sealing step; The stator assembly sealing ring is sleeved on the sealing step of the motor cavity housing.

6. The electronic oil pump according to claim 1, characterized in that: The connector assembly comprises a connector bracket and the connector terminal, and the connector terminal is fixed on the connector bracket; After the motor cavity shell is formed, the connector bracket of the connector assembly is embedded in the motor cavity shell.

7. The electronic oil pump according to claim 1, characterized in that: The outer sides of the oil inlet and the oil outlet of the pump cover component are both provided with sealing island structures; An oil inlet distribution cavity is formed inside the oil inlet of the pump cover member; An advance oil discharge cavity is formed inside the oil outlet of the pump cover member; An upper bearing chamber is formed on the inner side of the pump cover component, and the end of the rotating shaft is supported by the upper bearing chamber of the pump cover component; an upper oil inlet groove is formed at the upper bearing chamber of the pump cover component to supply oil to enter the upper bearing chamber and form an oil film at the gap between the upper bearing chamber and the rotating shaft.

8. The electronic oil pump according to claim 1, characterized in that: The power rotor assembly includes an inner rotor and an outer rotor forming a cycloidal gear rotor structure, wherein the number of teeth of the inner rotor is one less than the number of teeth of the outer rotor; The inner rotor of the power rotor assembly is sleeved on the rotating shaft and has an interference fit with the rotating shaft; An outward expansion structure is formed at the end of the inner hole of the inner rotor.

9. The electronic oil pump according to claim 1 or 8, characterized in that: The plastic coating layer of the motor rotor covers the end surface of the rotor core and the surface of the avoidance cavity, so that the side surface of the rotor core is an exposed structure.

10. The electronic oil pump according to claim 1, characterized in that: The driving circuit board is equipped with a position sensor; The rotating shaft is located at one end of the motor rotor chamber of the stator assembly, and is provided with an induction magnetic ring matching the position sensor of the driving circuit board; In addition, a shielding sleeve is provided on the rotating shaft to prevent the rotating shaft from causing magnetic field interference to the induction magnetic ring.

Images