Pressure self-sealing gear pump

Abstract

This invention provides a pressure-type self-sealing gear pump, comprising a housing, a gear set, a cover, a rotating shaft, a first hydraulic plate, a first sealing ring, and a second sealing ring. A pump chamber is formed by the external teeth of the internal gear and the internal teeth of the external gear. A partition component is provided within the pump chamber, dividing it into an oil inlet area and an oil outlet area. The first hydraulic plate is axially positioned between the end face of the gear set and the end face of the cover. The first hydraulic plate is provided with a shaft hole, a hydraulic inlet, and a hydraulic outlet. Both the first and second sealing rings axially abut against the end face of the first hydraulic plate and the end face of the cover. The hydraulic inlet is sealed and surrounded by the first sealing ring, and the hydraulic outlet is sealed and surrounded by the second sealing ring. The advantages of this invention are that by adding a first hydraulic plate, a first sealing ring, and a second sealing ring, a targeted end-face sealing system is constructed. Combined with the radial sealing system constructed by the partition component, this completely isolates the two main leakage paths of the gear pump, laying the foundation for improved pump efficiency.

Description

Technical Field

[0001] This invention relates to the field of gear pump technology, and more specifically, to a pressure-type self-sealing gear pump. Background Technology

[0002] With the automotive industry placing increasingly stringent demands on fuel economy and driving experience, dual-clutch transmissions have become the mainstream configuration for hybrid and gasoline vehicles due to their efficient shifting performance. Shift speed is the core performance indicator of a dual-clutch transmission; for example, some manufacturers claim their shift times can be reduced to less than 200 milliseconds. Currently, the industry generally uses a dual-gear pump solution to separately control the engagement and disengagement of odd and even gears, achieving rapid shifting through boost pressure.

[0003] However, in actual driving scenarios, 80% of driving time is concentrated on non-highway sections, requiring frequent gear shifting. Therefore, the efficiency of the gear pump is particularly crucial. The current gear pump structure includes a housing, gear set, cover, and shaft. The housing has a mounting groove. The gear set includes an external gear rotatably connected within the mounting groove and an internal gear eccentrically mounted and rotatably connected within the external gear. The external teeth of the internal gear and the internal teeth of the external gear enclose a pump chamber. The cover is detachably connected to the opening of the mounting groove in the housing, axially limiting the gear set within the groove. The cover has an oil inlet and an oil outlet, both of which communicate with the mounting groove. One end of the shaft passes through the bottom of the mounting groove and is connected to the stator assembly inside the housing. The other end of the shaft is rotatably connected to the cover and is fixedly connected to the internal gear. According to general mechanical principles, under this high-pressure condition, the overall efficiency of the pump is often less than 50%. The main reason is the severe internal leakage of the gear pump (flowing from the oil outlet area (high pressure) to the oil inlet area (low pressure)). The leakage mainly comes from two aspects: First, end face clearance leakage (axial), where oil leaks through the assembly gap between the gear set end face and the housing or cover. Due to the short leakage path and large flow area, it is extremely sensitive to the size of the gap. The end face leakage of a typical internal gear oil pump can account for 75% to 80%. Second, radial clearance leakage, where oil leaks through the radial clearance between the gear tooth tip and the pump body (or partition assembly). The leakage path is longer and more tortuous, with greater resistance, so the leakage is relatively smaller, accounting for about 15% to 25%. To compensate for the efficiency loss and maintain the shifting speed, existing solutions often use a more powerful electric pump and a larger motor, which leads to problems such as increased motor size, increased system weight, increased energy consumption, and decreased NVH performance.

[0004] Therefore, there is an urgent need for a technical solution that is both economical and feasible, which can effectively suppress end face leakage and improve the overall efficiency of the system without significantly increasing costs and complexity, so as to achieve lighter weight, faster shifting speed, lower energy consumption and better NVH performance. Summary of the Invention

[0005] The purpose of this invention is to overcome the defects of existing gear pumps, such as severe end face leakage, low efficiency, high energy consumption, and poor NVH performance. It provides a pressure-type self-sealing gear pump that effectively seals the gear end face gap by adding a first hydraulic plate, a first sealing ring, and a second sealing ring. The radial sealing system inside the gear pump cavity, constructed with the partition component, effectively suppresses the two main leakage paths of the gear pump, namely the end face and the radial direction, without significantly increasing cost and complexity, thereby improving pump efficiency and achieving lightweight, low energy consumption, and excellent NVH performance.

[0006] To achieve the objectives of this invention, the following technical solutions are adopted: A pressure-type self-sealing gear pump includes a housing, a gear set, a cover, and a rotating shaft. The housing has a mounting groove, and the gear set is installed within the mounting groove. The gear set includes an internal gear connected to the rotating shaft and an external gear eccentrically positioned and rotatably connected to the internal gear. The external teeth of the internal gear and the internal teeth of the external gear enclose a pump chamber. The cover is detachably connected to the mounting groove and axially restricts the gear set within the groove. The cover has an oil inlet and an oil outlet communicating with the pump chamber. One end of the rotating shaft passes through the bottom of the mounting groove and is connected to a stator assembly inside the housing. The other end of the rotating shaft is rotatably connected to the cover. The body also includes a first hydraulic plate, a first sealing ring, and a second sealing ring; a partition component is provided in the pump chamber to separate the pump chamber into an oil inlet area and an oil outlet area; the first hydraulic plate is axially limited between the end face of the gear set and the end face of the cover body, and the first hydraulic plate is respectively provided with a shaft hole for the shaft to pass through, a hydraulic inlet connecting the pump chamber and the oil inlet, and a hydraulic outlet connecting the pump chamber and the oil outlet; the first sealing ring and the second sealing ring are both axially abutted between the end face of the first hydraulic plate and the end face of the cover body, and the hydraulic inlet is sealed and surrounded by the first sealing ring, and the hydraulic outlet is sealed and surrounded by the second sealing ring. This structure, through the addition of a first hydraulic plate, a first sealing ring, and a second sealing ring, constructs a targeted end-face sealing system. This system seals and surrounds the hydraulic inlet and outlet, structurally blocking the direct leakage path between the high-pressure area of ​​the pump chamber and the outside. This significantly suppresses gear end-face clearance leakage, which accounts for 75% to 80% of the total leakage. Simultaneously, the newly designed partition component forms a radial sealing system within the gear pump chamber, completely isolating the two main leakage paths of the gear pump. This lays a core foundation for improved pump efficiency. Furthermore, the shaft hole, hydraulic inlet, and hydraulic outlet on the first hydraulic plate precisely match the structure of the original housing, cover, gear set, and shaft, ensuring smooth oil inlet and outlet channels. While achieving enhanced sealing, this does not affect the original booster drive function of the gear pump, ensuring the continuity of gear shifting. At the same time, the sealing structure axially limits the connection between the gear set and the cover. The design does not require significant modifications to core components such as the gear pump housing, gear set, and shaft, and is compatible with the existing dual-gear pump assembly logic, demonstrating good technical compatibility and feasibility.

[0007] Preferably, the separating assembly includes an intermediate shaft, an upper swing member, and a lower swing member. The intermediate shaft is axially mounted on the pump chamber, and the upper and lower swing members are respectively fitted onto the upper and lower sides of the intermediate shaft and rotatably engage with it. An inlet swing gap is provided between the upper and lower swing members on the side of the intermediate shaft near the oil inlet, and an outlet swing gap is provided between the upper and lower swing members on the side of the intermediate shaft near the oil outlet. The width of the outlet swing gap is greater than the width of the inlet swing gap. When a pressure difference is formed in the pump chamber and the outlet swing gap is opened, the outer wall of the upper swing member abuts against the inner teeth of the external gear to achieve a seal. The outer wall of the lower swing member abuts against the outer teeth of the internal gear, forming a radial sealing system for the gear pump chamber to separate the oil inlet side (low-pressure chamber) and the oil outlet side (high-pressure chamber) of the pump chamber. The upper and lower swing parts are fitted with the intermediate shaft with a clearance. Oil from the outlet swing gap (high pressure chamber) will pass through the clearance to the inlet swing gap (low pressure chamber). The width of the outlet swing gap is greater than the width of the inlet swing gap. This structure allows the upper and lower swing parts to be pushed towards the low pressure direction when oil pressure enters the low pressure chamber through the gap, until the upper and lower swing parts are close to the high pressure area and tightly pressed against the intermediate shaft. A seal is formed at the contact point, preventing oil from the high pressure area from entering the low pressure area through the gap. Afterward, the pressure direction of the high pressure oil on the upper and lower swing parts continues towards the low pressure area, and the sealing position remains unchanged to maintain the sealing effect, further ensuring the sealing effect, preventing oil leakage to the low pressure area, and improving pump efficiency.

[0008] Preferably, the first hydraulic plate is provided with a first positioning hole that axially positions and engages with the intermediate shaft, and the end face of the cover near the first hydraulic plate is provided with a first positioning groove. One end of the intermediate shaft passes through the first positioning hole and is axially inserted into the first positioning groove. The intermediate shaft and the first positioning groove are positioned and engaged to achieve circumferential limiting. Through the positioning engagement between the intermediate shaft and the first positioning groove, the circumferential limiting of the first hydraulic plate and the cover is achieved, preventing the hydraulic plate from shifting circumferentially due to factors such as gear rotation and hydraulic shock during the operation of the gear pump, and ensuring that the hydraulic inlet and outlet are always precisely aligned with the oil inlet and outlet.

[0009] Preferably, a sealing ring groove is provided on the end face of the cover near the first hydraulic plate, and the opening of the sealing ring groove faces the first hydraulic plate. The bottom of the sealing ring groove is circumferentially recessed with an annular step, and the annular step is close to the inner peripheral wall of the sealing ring groove. The second sealing ring is disposed in the sealing ring groove and covers the outside of the annular step. An oil inlet gap communicating with the annular step is formed between the inner peripheral wall of the second sealing ring and the inner peripheral wall of the sealing ring groove. During operation, hydraulic oil flows into the annular step along the oil inlet gap, and under the action of oil pressure, the hydraulic oil in the oil inlet gap acts radially on the inner peripheral wall of the second sealing ring, and the hydraulic oil in the annular step acts axially on the end face of the second sealing ring near the cover. The outer end face of the cover located in the sealing ring groove is higher than the inner end face of the cover located in the sealing ring groove, so that the outer end face and the inner end face form a step difference to facilitate the entry of hydraulic oil. The above-described structure, utilizing the sealing ring groove, annular step, and oil inlet gap, allows hydraulic oil to flow into the annular step and act on the second sealing ring during operation. The radial force of the hydraulic oil ensures that the sealing ring is tightly attached to the inner wall of the outer side of the sealing ring groove, while the axial force enhances the fit between the sealing ring and the end face of the first hydraulic plate, forming a "system pressure self-driven seal." The sealing effect is strengthened as the system oil pressure increases, further reducing end face leakage. By creating a step difference between the outer and inner end faces, the resulting oil inlet gap under system pressure facilitates the entry of hydraulic oil.

[0010] Preferably, the hydraulic inlet and hydraulic outlet are located on both radial sides of the shaft hole and are both arc-shaped, with the openings of the hydraulic inlet and hydraulic outlet facing the shaft hole. Reinforcing ribs distributed radially are provided in the middle of both the hydraulic inlet and hydraulic outlet. The second sealing ring and the first sealing ring are symmetrically arranged on both radial sides of the shaft hole, and the sealing structures of the second sealing ring and the first sealing ring are identical. The arc-shaped openings of the hydraulic inlet and hydraulic outlet facing the shaft hole adapt to the rotation trajectory of the gear set and the flow path of the hydraulic oil, further optimizing the flow efficiency. The reinforcing ribs in the middle enhance the structural strength of the first hydraulic plate without affecting hydraulic flow, preventing deformation of the hydraulic plate due to high pressure or long-term use. This structure ensures that the sealing strength and sealing principle on both sides of the hydraulic inlet and hydraulic outlet are consistent, achieving bidirectional high-efficiency sealing of the inlet and outlet channels, completely blocking leakage paths at both ends. Furthermore, the symmetrical structure ensures that the sealing force on both radial sides of the first hydraulic plate is evenly distributed, preventing deformation or uneven wear of the hydraulic plate due to excessive sealing pressure on one side, ensuring smooth rotation of the gear set, reducing mechanical wear, and indirectly improving pump efficiency.

[0011] Preferably, the cross-sectional area of ​​the hydraulic inlet is larger than the cross-sectional area of ​​the oil inlet area of ​​the pump chamber, and the cross-sectional area of ​​the hydraulic outlet is larger than the cross-sectional area of ​​the oil outlet area of ​​the pump chamber; the oil pressure area S1 on the end face of the first hydraulic plate near the gear set is smaller than the oil pressure area S2 on the end face of the first hydraulic plate away from the gear set. This structure reduces the flow resistance of hydraulic oil in the inlet and outlet channels, ensuring sufficient hydraulic oil quickly enters the pump chamber and is discharged promptly, guaranteeing the hydraulic response speed required for gear shifting. Through the area difference design, when system oil pressure is generated, the back pressure generated by the area of ​​hydraulic plate S2 is greater than the pushing force generated by the area of ​​S1, thus pressing the hydraulic plate against the gear end face. Utilizing this principle, after the pump starts, the hydraulic plate will always be tightly attached to the gear end face, automatically compensating for minor gaps caused by wear or manufacturing tolerances. Once there is slight wear on the gear end face, the hydraulic plate will immediately follow up under the back pressure, always maintaining a very small, almost leak-free gap.

[0012] Preferably, the first hydraulic plate has at least one lubrication groove on its end face near the gear set to reduce friction. The lubrication groove design reduces the contact area between the first hydraulic plate and the gear set end face, lowering the friction between them, reducing mechanical wear, and improving the pump's mechanical efficiency. Simultaneously, it reduces the heat generated by friction, mitigating the impact of high temperatures on the seals and hydraulic oil performance.

[0013] Preferably, the first hydraulic plate has a first cooling groove and a second cooling groove on its end face near the gear set. The first and second cooling grooves are located on opposite radial sides of the shaft hole. The first cooling groove is located radially outside the hydraulic inlet and corresponds to the oil inlet area of ​​the gear set, while the second cooling groove is located radially outside the hydraulic outlet and corresponds to the oil outlet area of ​​the gear set. By having the first and second cooling grooves arranged in an arc shape to correspond to the oil inlet and outlet areas of the gear set, the heat dissipation area of ​​the hydraulic plate is increased. Furthermore, the hydraulic oil in the cooling grooves can circulate rapidly, efficiently carrying away the heat generated by the operation and friction of the gear set, thus reducing the operating temperature of the gear set and the hydraulic plate.

[0014] Preferably, the housing has an annular mounting cavity for mounting the stator assembly circumferentially, and a support portion protrudes from the center of the annular mounting cavity on the housing. A bearing hole is axially inserted through the center of the support portion, and the rotating shaft passes axially through the bearing hole and is rotatably connected to the bearing hole via a first bearing. Several heat-conducting connecting ribs are evenly distributed circumferentially within the annular mounting cavity. One radial end of each heat-conducting connecting rib is connected to the outer wall of the support portion, and the other radial end is connected to the inner wall of the outer side of the housing. The heat-conducting connecting ribs allow the high-speed rotation of the shaft during pump operation, with the heat generated by friction with the bearing concentrated in the support portion, to be conducted to the outer wall of the housing and dissipated to the outside. The same structure can also be applied to the cover.

[0015] Preferably, a second hydraulic plate is also included. The second hydraulic plate has the same structure as the first hydraulic plate and is symmetrically arranged on both axial end faces of the gear set, and is axially limited between the gear set and the bottom of the housing groove of the mounting slot. By symmetrically arranging the second and first hydraulic plates on both axial sides of the gear set, a complete seal is achieved on both end faces of the gear set, completely blocking the leakage path on both sides of the gear. The sealing effect is significantly improved compared to single-sided sealing, further reducing the total leakage.

[0016] The advantages of this invention are: through innovative sealing structure and optimized structural design, multiple core technological effects are achieved. First, sealing performance is significantly improved. The newly added first hydraulic plate, combined with double sealing rings and a self-reinforcing design of sealing ring groove, annular step, and oil inlet gap, utilizes system oil pressure to achieve dynamic sealing and wear compensation. Theoretically, this makes the gear end face clearance approach zero, significantly suppressing end face leakage, which accounts for 75% to 80% of the total leakage, and greatly improving the volumetric efficiency of the internal gear pump. Second, replacing the traditional crescent plate design, an innovatively designed sealing swing component is adopted. The upper and lower swing parts use system pressure to fit against the internal and external gears, sealing and isolating the oil inlet area and oil outlet area (low-pressure chamber and high-pressure chamber) of the pump chamber, achieving a radial sealing effect. Through the difference in the width of the swing gap between the outlet and inlet, the effective sealing between the upper and lower swing parts and the intermediate shaft is ensured, further optimizing the radial sealing effect in the pump chamber, preventing oil leakage from the high-pressure chamber (oil outlet area) to the low-pressure chamber (oil inlet area), and further improving pump efficiency. Thirdly, significant progress has been made in lightweighting and energy consumption optimization. Improved efficiency due to enhanced sealing, combined with reduced friction designs in the hydraulic disc and bearings, greatly reduces the motor load. Compared to existing traditional electronic oil pumps, a 150W motor can achieve the efficiency of a 300W motor, reducing energy consumption by over 50%. Simultaneously, the smaller motor means that other gear pump components, such as the motor housing, can be correspondingly reduced in size, directly and indirectly meeting the overall vehicle lightweighting requirements. Fourthly, improved shifting speed and NVH performance are achieved. The low-friction coefficient POM hydraulic plate, combined with multiple grooves for friction reduction and a cooling groove structure, reduces friction, vibration, and noise while ensuring hydraulic response speed for rapid shifting. Fifthly, strong structural compatibility is achieved without significant modifications to the original gear pump core components. Assembly is convenient and cost-effective, combining economic efficiency and feasibility, effectively solving the pain points of existing technologies such as large motor size, high energy consumption, and poor NVH. Attached Figure Description

[0017] Figure 1 is a structural schematic diagram of the pressure-type self-sealing gear pump of the present invention. Figure 2 is a cross-sectional view of the partition assembly of the present invention. Figure 3 is a schematic diagram of the sealing position of the partition assembly of the present invention. Figure 4 is a cross-sectional view of the pressure-type self-sealing gear pump of the present invention. Figure 5 is... Figure 4Partial enlarged schematic diagrams. Figure 6 is a structural schematic diagram of the cover body of the present invention. Figure 7 is a frontal exploded view of the pressure-type self-sealing gear pump of the present invention. Figure 8 is a reverse exploded view of the pressure-type self-sealing gear pump of the present invention. Figure 9 is a plan view of the gear set and hydraulic plate of the present invention. Figure 10 is a structural schematic diagram of the external gear of the present invention. Explanation of reference numerals: 1. Housing; 11. Mounting groove; 111. Housing groove opening; 112. Housing groove bottom; 12. Stator assembly; 13. Annular mounting cavity; 14. Support part; 15. Heat-conducting connecting rib; 2. External gear; 20. Pump chamber; 201. Oil inlet area; 202. Oil outlet area; 21. Weight reduction hole; 3. Internal gear; 4. Cover; 41. Oil inlet; 42. Oil outlet; 43. Sealing ring groove; 431. Sealing groove bottom; 432. Annular step; 433. Oil inlet gap; 434. Inner end face; 435. Outer end face Surface; 44, First positioning groove; 5, Rotating shaft; 6, First hydraulic plate; 61, Shaft hole; 62, Hydraulic inlet; 63, Hydraulic outlet; 64, First positioning hole; 65, Reinforcing rib; 66, First cooling tank; 67, Second cooling tank; 68, Third cooling tank; 7, First sealing ring; 8, Second sealing ring; 9, Second hydraulic plate; 91, Second positioning hole; 10, Separating assembly; 101, Intermediate shaft; 102, Upper swing piece; 103, Lower swing piece; 104, Inlet swing clearance; 105, Outlet swing clearance. Detailed Implementation

[0018] First, those skilled in the art should understand that these embodiments are merely used to explain the technical principles of the embodiments of this application and are not intended to limit the scope of protection of the embodiments of this application. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.

[0019] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0020] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0021] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0022] like Figures 1 to 10As shown, the pressure-type self-sealing gear pump includes a housing 1, a gear set, a cover 4, a rotating shaft 5, a first hydraulic plate 6, a first sealing ring 7, and a second sealing ring 8. The housing 1 is provided with a mounting groove 11, and the gear set is installed in the mounting groove 11. The gear set includes an internal gear 3 connected to the rotating shaft 5 and an external gear 2 eccentrically arranged and rotatably connected to the outside of the internal gear 3. The external teeth of the internal gear 3 and the internal teeth of the external gear 2 enclose a pump chamber 20. A partition component 10 is provided in the pump chamber 20 to separate the pump chamber 20 into an oil inlet area (low-pressure chamber) and an oil outlet area (high-pressure chamber). The cover 4 is detachably connected to the housing 1 (at the housing groove 111 of the mounting groove 11), and axially limits the gear set within the mounting groove 11. The cover 4 is provided with an oil inlet 41 and an oil outlet 42 communicating with the pump chamber 20. One end of the rotating shaft 5 passes through the bottom 112 of the housing groove 11 and is connected to the stator assembly 12 inside the housing 1 for transmission. The other end of the rotating shaft 5 is rotatably connected to the cover 4, and the middle section of the rotating shaft 5 is fixedly connected to the internal gear 3. The first hydraulic plate 6 is axially (along the length of the rotating shaft 5). The direction is limited between the end face of the gear set and the end face of the cover 4. The first hydraulic plate 6 is provided with a shaft hole 61 for the shaft 5 to pass through, a hydraulic inlet 62 connecting the pump chamber 20 and the oil inlet 41, and a hydraulic outlet 63 connecting the pump chamber 20 and the oil outlet 42. The first sealing ring 7 and the second sealing ring 8 are both axially abutted between the end face of the first hydraulic plate 6 and the end face of the cover 4. The hydraulic inlet 62 is sealed and surrounded by the first sealing ring 7, and the hydraulic outlet 63 is sealed and surrounded by the second sealing ring 8. This structure, through the addition of a first hydraulic plate 6, a first sealing ring 7, and a second sealing ring 8, constructs a sealing system for the gear set end face. The hydraulic inlet 62 and hydraulic outlet 63 are each sealed and surrounded by independent sealing rings. Structurally, the first hydraulic plate 6 fits snugly against the gear set end face, and the double sealing rings provide elastic pressure and compensate for the gaps between the first hydraulic plate 6, the gear set end face, and the cover 4, effectively blocking the direct leakage channel between the high-pressure area of ​​the pump chamber 20 and the outside. This significantly suppresses the gear end face gap leakage, which accounts for 75% to 80% of the total leakage. Simultaneously, the newly designed partition component constructs a radial sealing system within the gear pump cavity, completely isolating... The elimination of the two main leakage paths of the gear pump lays a core foundation for improving pump efficiency. Furthermore, the shaft hole 61, hydraulic inlet 62, and hydraulic outlet 63 on the first hydraulic plate 6 are precisely matched with the original structure of the housing 1, cover 4, gear set, and rotating shaft 5, ensuring smooth oil inlet and outlet channels. While achieving enhanced sealing, it does not affect the original booster drive function of the gear pump, ensuring the continuity of gear shifting. At the same time, the sealing structure is axially limited between the gear set and the cover 4, eliminating the need for significant modifications to the core basic components such as the gear pump housing 1, gear set, and rotating shaft 5. It is compatible with the overall assembly logic of existing gear pumps and has good technical compatibility and feasibility.

[0023] like Figures 2 to 3As shown, the separator assembly 10 includes an intermediate shaft 101, an upper swing member 102, and a lower swing member 103. The intermediate shaft 101 is axially connected to the pump chamber 20. The upper swing member 102 and the lower swing member 103 are respectively sleeved on the upper and lower sides of the intermediate shaft 101 and rotate in cooperation with the intermediate shaft 101. An inlet swing gap 104 is provided between the upper swing member 102 and the lower swing member 103 on the side of the intermediate shaft 101 near the oil inlet 41. An inlet swing gap 104 is provided between the upper swing member 102 and the lower swing member 103 on the side of the intermediate shaft 101 near the oil outlet 41. An outlet swing gap 105 is provided between the upper swing member 102 and the lower swing member 103 on one side, and the spacing width of the outlet swing gap 105 is greater than the spacing width of the inlet swing gap 104. When a pressure difference is formed in the pump chamber 20 and the outlet swing gap 105 is opened, the outer wall of the upper swing member 102 abuts against the inner teeth of the external gear 2 to achieve a seal; the outer wall of the lower swing member 103 abuts against the outer teeth of the internal gear 3 to separate the oil inlet side and the oil outlet side of the pump chamber 20. In actual production, due to manufacturing tolerances, the intermediate shaft 101 and the upper and lower swing parts cannot achieve an ideal state (zero gap state and the outlet swing gap 105 and the inlet swing gap 104 are equal). As a result, oil pressure will leak directly into the low-pressure area through this gap. However, in this embodiment, the outlet swing gap 105 (high pressure chamber distance) is larger than the inlet swing gap 104 (low pressure chamber distance). During operation, the oil in the outlet swing gap 105 (high pressure chamber) will pass through the fitting gap to the inlet swing gap 104 (low pressure chamber). This structure can push the upper and lower swing parts towards the low pressure direction when the oil pressure enters the low pressure chamber through the gap, until the upper and lower swing parts are close to the high pressure area side and tightly attached to the intermediate shaft 101. A seal is formed at the contact point, so that the oil in the high pressure area no longer enters the low pressure area through the gap. After that, the pressure direction of the oil pressure in the high pressure area acting on the upper and lower swing parts is always towards the low pressure area. The sealing position remains unchanged and the sealing effect is maintained, further ensuring the sealing effect, preventing oil leakage to the low pressure area, and improving pump efficiency.

[0024] like Figures 4 to 6As shown, a sealing ring groove 43 is provided on the end face of the cover 4 near the first hydraulic plate 6, and the opening of the sealing ring groove 43 faces the first hydraulic plate 6. The bottom 431 of the sealing groove of the sealing ring groove 43 is provided with an annular step 432 in the circumferential direction, and the annular step 432 is close to the inner peripheral wall of the sealing ring groove 43, and the inner peripheral wall of the annular step 432 is coplanar with the inner peripheral wall of the sealing ring groove 43. The first sealing ring 7 is disposed in the sealing ring groove 43 and covers the outer side of the annular step 432. An oil inlet gap 433 communicating with the annular step 432 is formed between the inner peripheral wall of the first sealing ring 7 and the inner peripheral wall of the sealing ring groove 43. The oil inlet gap 433 and the annular step 432 cooperate to form an L-shaped oil inlet channel. During operation, hydraulic oil flows into the annular step 432 along the oil inlet gap 433. Under the action of oil pressure, the hydraulic oil in the oil inlet gap 433 acts radially on the inner peripheral wall of the first sealing ring 7, and the hydraulic oil in the annular step 432 acts axially on the end face of the first sealing ring 7 near the cover 4. By utilizing the structural design of the sealing ring groove 43, the annular step 432, and the oil inlet gap 433, hydraulic oil can flow into the annular step 432 and act on the first sealing ring 7 during operation. The radial force of the hydraulic oil ensures that the first sealing ring 7 is tightly attached to the inner wall (outer inner circumferential wall) of the sealing ring groove 43, while the axial force enhances the fit between the first sealing ring 7 and the end faces of the first hydraulic plate 6 and the cover 4, forming a "system pressure self-driven seal." The sealing effect is strengthened as the system oil pressure increases, further reducing leakage at the gear set end face. Furthermore, the bidirectional action of oil pressure on the first sealing ring 7 not only actively suppresses leakage but also dynamically compensates for wear and assembly clearance, extending the service life of the sealing structure and preventing pump efficiency reduction due to sealing performance degradation after long-term use. Simultaneously, the matching design of the annular step 432 and the oil inlet gap 433 ensures that the hydraulic oil acts evenly on the first sealing ring 7, avoiding seal failure caused by uneven local force distribution. This is particularly suitable for high-frequency operating conditions such as frequent gear shifting in vehicles, ensuring the stability of sealing performance. Furthermore, the outer end face 435 of the cover 4 located in the sealing ring groove 43 is higher than the inner end face 434 of the cover 4 located in the sealing ring groove 43. By creating a step difference between the outer end face 435 and the inner end face 434, the oil inlet gap generated under system pressure facilitates the entry of hydraulic oil.

[0025] like Figure 7 and Figure 8As shown, the hydraulic inlet 62 and hydraulic outlet 63 are symmetrically arranged on both radial sides of the shaft hole 61, and both are arc-shaped, with the openings of the hydraulic inlet 62 and hydraulic outlet 63 facing the shaft hole 61. The arc-shaped openings of the hydraulic inlet 62 and hydraulic outlet 63 facing the shaft hole 61 adapt to the rotation trajectory of the gear set and the flow path of the hydraulic oil, further optimizing the flow efficiency. Radially distributed reinforcing ribs 65 are provided in the middle of both the hydraulic inlet 62 and hydraulic outlet 63. The reinforcing ribs 65 in the middle enhance the structural strength of the first hydraulic plate 6 without affecting the hydraulic flow, preventing deformation of the hydraulic plate due to high pressure or long-term use. Furthermore, the symmetrically arranged arc-shaped inlets and outlets make the force of the hydraulic oil on the first hydraulic plate 6 more uniform, reducing local stress concentration, extending the service life of the first hydraulic plate 6, and ensuring a stable fit of the sealing structure. At the same time, the arc-shaped structure facilitates machining and is compatible with the structural shape of the gear set and cover 4, ensuring the fit of the first hydraulic plate 6 with other components, indirectly improving the sealing effect and hydraulic transmission efficiency.

[0026] In this embodiment, as Figures 7 to 8 As shown, the second sealing ring 8 and the first sealing ring 7 are symmetrically arranged on both radial sides of the shaft hole 61, and both are cashew-shaped, surrounding the outside of the hydraulic inlet 62 and the hydraulic outlet 63. The sealing structures (sealing ring groove 43, annular step 432, and oil inlet gap 433) and sealing effects of the second sealing ring 8 and the first sealing ring 7 are identical, and will not be elaborated further here. By maintaining consistent sealing strength and sealing principle on both sides of the hydraulic inlet 62 and the hydraulic outlet 63, bidirectional high-efficiency sealing of the inlet and outlet oil channels is achieved, completely blocking the leakage paths on both radial sides of the gear set end face. Furthermore, the symmetrical structure ensures that the sealing force on the first hydraulic plate 6 is evenly distributed radially, preventing deformation or uneven wear of the first hydraulic plate 6 due to excessive sealing pressure on one side, ensuring smooth rotation of the gear set, reducing mechanical wear, and indirectly improving pump efficiency. Simultaneously, the symmetrical design using the same sealing structure reduces the types and design complexity of sealing components, facilitating processing, manufacturing, and assembly, thereby improving the sealing effect while controlling the implementation cost of the technical solution.

[0027] like Figure 7 and Figure 8As shown, the first hydraulic plate 6 is provided with a first positioning hole 64 that axially positions and engages with the intermediate shaft 101. A first positioning groove 44 is provided on the end face of the cover 4 near the first hydraulic plate 6. One end of the intermediate shaft 101 passes through the first positioning hole 64 and is axially inserted into the first positioning groove 44. The intermediate shaft 101 and the first positioning groove 44 are positioned and engaged to achieve circumferential positioning. Through the axial positioning engagement of the intermediate shaft 101 and the first positioning groove 44, the first hydraulic plate 6 and the cover 4 are circumferentially positioned, preventing circumferential displacement of the first hydraulic plate 6 due to gear rotation, hydraulic shock, and other factors during gear pump operation. This ensures that the hydraulic inlet 62, hydraulic outlet 63, oil inlet 41, and oil outlet 42 are always precisely aligned. Circumferential positioning prevents problems such as uneven force on the sealing ring and increased sealing gap caused by the displacement of the first hydraulic plate 6, maintaining the integrity and sealing performance of the sealing structure and avoiding leakage risks caused by positioning failure. Meanwhile, the mating structure between the intermediate shaft 101 and the first positioning groove 44 facilitates quick and accurate positioning during assembly, reduces assembly difficulty, improves production assembly efficiency, and ensures product consistency during mass production.

[0028] like Figure 9 As shown, in this embodiment, the cross-sectional area of ​​the hydraulic inlet 62 is larger than the cross-sectional area of ​​the oil inlet area 201 of the pump chamber 20, and the cross-sectional area of ​​the hydraulic outlet 63 is larger than the cross-sectional area of ​​the oil outlet area 202 of the pump chamber 20. This structure reduces the flow resistance of hydraulic oil in the inlet and outlet channels, ensuring sufficient hydraulic oil quickly enters the pump chamber 20 and is discharged promptly, guaranteeing the hydraulic response speed required for gear shifting. Furthermore, the spacious inlet and outlet channel design avoids pressure loss due to insufficient flow cross-section, allowing the system pressure to act more efficiently on the gear set and gear shifting actuator, meeting the need for rapid gear shifting even with a smaller power motor. While ensuring flow efficiency, the sealing effect of the first sealing ring 7 and the second sealing ring 8 achieves both "high flow rate" and "low leakage," avoiding the problem of sacrificing sealing performance for the sake of flow efficiency, thus achieving a balance between sealing and flow. The oil pressure area S1 on the end face of the first hydraulic plate 6 near the gear set is smaller than the oil pressure area S2 on the end face of the first hydraulic plate 6 away from the gear set. Through the area difference design, when the system oil pressure is generated, the back pressure generated by the hydraulic plate's oil pressure area S2 is greater than the pushing force generated by the oil pressure area S1, thus pressing the hydraulic plate against the gear end face. Utilizing this principle, after the pump starts, the hydraulic plate will always remain tightly pressed against the gear set end face, automatically compensating for minute gaps caused by wear or manufacturing tolerances. If there is even a slight wear on the gear set end face, the hydraulic plate will immediately follow up under the back pressure, always maintaining an extremely small, near-leak-free gap.

[0029] like Figure 7 and Figure 8As shown, the end face of the first hydraulic plate 6 near the gear set is provided with several lubrication grooves to reduce friction. Specifically, the lubrication grooves are: a first cooling groove 66, a second cooling groove 67, and a third cooling groove 68 are provided on the end face of the first hydraulic plate 6 near the gear set. The first cooling groove 66 and the second cooling groove 67 are symmetrically arranged on both radial sides of the shaft hole 61. The first cooling groove 66 surrounds the hydraulic inlet 62, and the bottom of the first cooling groove 66 extends to the radial outer side of the hydraulic inlet 62 and communicates with the hydraulic inlet 62. The second cooling groove 67 surrounds the hydraulic outlet 63, and the bottom of the second cooling groove 67 extends to the radial outer side of the hydraulic outlet 63 and communicates with the hydraulic outlet 63. The third cooling groove 68 surrounds the shaft hole 61, and the bottom of the third cooling groove 68 extends to the outer ring of the shaft hole 61 and communicates with the shaft hole 61. The first cooling groove 66 and the second cooling groove 67, arranged in an arc shape, surround the hydraulic inlet 62 and the hydraulic outlet 63. The third cooling groove 68, arranged in a circle, surrounds the shaft hole 61, increasing the heat dissipation area of ​​the first hydraulic plate 6. The hydraulic oil within the cooling grooves circulates rapidly, efficiently carrying away the heat generated by the gear set's operation and friction, thus reducing the operating temperature of the hydraulic oil and seals. Furthermore, the cooling grooves are located radially outside the hydraulic inlet 62 and the hydraulic outlet 63, ensuring that the sealing range of the sealing ring is not affected while specifically cooling the sealing and friction areas. This prevents seal failure and leakage risks caused by high temperatures leading to seal aging and decreased hydraulic oil viscosity. The effective heat dissipation design allows the gear pump to maintain a stable operating temperature under high-frequency shifting and high-pressure conditions, preventing performance degradation due to overheating and ensuring the stability of pump efficiency and the reliability of shifting actions. Simultaneously, the groove structure allows oil to circulate, further lubricating the friction surfaces, reducing wear, and assisting in carrying away the heat generated by friction, achieving a synergistic effect of lubrication, cooling, and friction reduction.

[0030] In this embodiment, as Figure 7 and Figure 8As shown, it also includes a second hydraulic plate 9. Both the second hydraulic plate 9 and the first hydraulic plate 6 are made of materials with low coefficient of friction, such as plastic or POM, which can effectively reduce friction loss and operating noise. The second hydraulic plate 9 has the same structure as the first hydraulic plate 6 (shaft hole 61, hydraulic inlet 62, hydraulic outlet 63, reinforcing rib 65, cooling groove) and is symmetrically arranged on both axial end faces of the gear set. The second hydraulic plate 9 is axially limited between the gear set and the bottom 112 of the housing groove of the mounting groove 11. A second positioning hole 91 is provided on the end face of the second hydraulic plate 9 away from the cover 4. A second positioning groove is provided on the bottom 112 of the housing groove. One end of the intermediate shaft 101 passes through the first positioning hole 64 and is axially inserted into the first positioning groove 44. The other end of the intermediate shaft 101 passes through the second positioning hole 91 and is axially inserted into the second positioning groove. The intermediate shaft 101 and the second positioning groove are positioned and cooperated to achieve circumferential limitation. At the same time, the intermediate shaft 101 connects and limits the second hydraulic plate 9, the first hydraulic plate 6 and the gear set axially. By symmetrically positioning the second hydraulic plate 9 and the first hydraulic plate 6 on both sides of the gear set's axial direction, a complete seal is achieved on both end faces of the gear set. Under the action of system oil pressure, the end faces of the gear set are pressed together, achieving a theoretical zero clearance and completely blocking the leakage path on both sides of the gear's end faces. The sealing effect is significantly improved compared to single-sided sealing, further reducing the total leakage. Furthermore, the symmetrically positioned double hydraulic plates ensure a uniform distribution of axial sealing pressure on the gear set, avoiding problems such as uneven wear of the gear set and uneven force on the shaft 5 caused by excessive pressure on one side. This ensures smooth rotation of the gear set and reduces mechanical wear. The double-sided sealing further suppresses leakage, significantly improving the pump's overall efficiency. This provides key technical support for achieving "gear switching within 150ms with a 150W motor," while also further reducing energy consumption and NVH (noise, vibration, and harshness).

[0031] In this embodiment, as Figure 4 As shown, an annular mounting cavity 13 for mounting the stator assembly 12 is provided circumferentially inside the housing 1. A support portion 14 protrudes from the center of the annular mounting cavity 13 on the housing 1. A bearing hole is axially inserted through the center of the support portion 14. The rotating shaft 5 passes axially through the bearing hole and is rotatably connected to the bearing hole via a first bearing 51. Several heat-conducting connecting ribs 15 are evenly distributed circumferentially inside the annular mounting cavity 13. One radial end of each heat-conducting connecting rib 15 is connected to the outer wall of the support portion 14, and the other radial end of the heat-conducting connecting rib 15 is connected to the inner wall of the outer side of the housing 1. Through the heat-conducting connecting ribs 15, the rotating shaft can rotate at high speed during pump operation. The heat generated by friction with the bearing is concentrated in the support portion 14. The heat can be conducted to the outer wall of the housing 1 through the heat-conducting connecting ribs 15, thereby dissipating heat to the outside. The same structure can also be applied to the cover 4, thereby achieving the effect of heat dissipation at the end of the cover 4.

[0032] In this embodiment, as Figure 10As shown, several weight-reducing holes 21 are evenly distributed circumferentially on the external gear 2, and each weight-reducing hole 21 is located in the middle of the internal teeth of the external gear 2, and each weight-reducing hole 21 penetrates the external gear 2 axially. In specific applications, the weight-reducing holes 21 can also be set on the internal gear 3, or both the external gear 2 and the internal gear 3 can be equipped with weight-reducing holes 21. The external gear 2 is eccentrically arranged with the rotating shaft 5. After weight reduction optimization, without affecting product reliability, it reduces the moment of inertia, reduces the acceleration time of the motor, and also has a positive effect on reducing starting current, reducing heat generation, improving efficiency, and improving NVH. The moment of inertia is the "moment of inertia" of the mass distribution relative to the rotating shaft 5, which means that the contribution of the mass away from the axis to the moment of inertia increases quadratically. By using the weight-reducing holes 21 on the external gear 2 to penetrate axially, the weight of the external gear is reduced without affecting the strength of the gear structure and the transmission performance, thereby reducing the overall weight of the gear pump, which meets the requirements of vehicle lightweighting. The reduced gear weight decreases rotational inertia, resulting in faster response times during gear set startup and gear shifting. This improves shifting agility, and combined with the efficiency gains from the sealing structure, further shortens shifting time. The reduced rotational inertia decreases the energy consumption required to drive the gear set, which, in conjunction with the reduced leakage losses from the sealing structure, allows the gear pump to meet performance requirements even with a smaller motor, achieving significant energy savings.

[0033] When the gear pump is working, such as Figure 7 As shown, the stator assembly 12 drives the shaft 5 to rotate the internal gear 3 clockwise (to the right). The internal gear 3 meshes with the external gear 2, causing the volume of the pump chamber 20 to change. Hydraulic oil enters the oil inlet area 201 of the pump chamber 20 from the oil inlet 41 through the hydraulic inlet 62. As the internal gear 3 rotates clockwise, the volume of the oil inlet area 201 (left side) gradually increases, and the volume of the oil outlet area 202 (right side) gradually decreases. The hydraulic oil is discharged from the oil outlet area 202 through the hydraulic outlet 63 and from the oil outlet 42, achieving a pressurization effect (the low-pressure oil (about 1 bar) from the oil inlet 41 is pressurized by the gear pump and then output as high-pressure oil (about 14 bar) from the oil outlet 42). In terms of sealing, hydraulic oil flows into the annular step 432 through the oil inlet gap 433, generating radial and axial pressure on the sealing ring. Combined with the pressure difference on the back of the hydraulic plate, the hydraulic plate presses against the end face of the gear set, achieving zero-gap sealing and automatic wear compensation. In terms of friction reduction and heat dissipation, the low-friction coefficient hydraulic plate, along with the design of grooves and cooling slots, reduces frictional resistance and heat generation, improving NVH performance. In terms of high efficiency and lightweight, the large flow area design and the weight-reducing hole 21 structure enable a 150W motor to achieve a fast gear shift of 150ms, reducing energy consumption by 50% and significantly reducing weight.

[0034] The core design concept of this invention is to use the pressure generated by the pump system itself for internal sealing and wear compensation. Through the design of the newly added hydraulic plate, sealing ring, partition components and supporting structures, the end face leakage and radial leakage are effectively suppressed, while the friction, heat dissipation and other performance are optimized.

[0035] End face sealing principle: The first hydraulic plate 6 is axially limited between the gear set and the cover 4, and the second hydraulic plate 9 is axially limited between the gear set and the bottom of the housing groove 112. The oil pressure area S1 on the end face of the first hydraulic plate 6 near the gear set is smaller than the oil pressure area S2 on the end face of the first hydraulic plate 6 away from the gear set. Under the system oil pressure, the back pressure generated by the area of ​​hydraulic plate S2 is greater than the pushing force generated by the area of ​​S1, thereby pressing the hydraulic plate against the end face of the gear to achieve end face sealing of the gear pump. The first sealing ring 7 and the second sealing ring 8 respectively seal and surround the hydraulic inlet 62 and the hydraulic outlet 63. At the same time, the elastic compression of the sealing ring is used to compensate for the manufacturing tolerance gap between the end face of the hydraulic plate and the gear set, constructing a basic sealing system and blocking the leakage channel of the gear pump end face. The sealing ring groove 43 and the annular step 432 on the cover 4 cooperate with the oil inlet gap 433, so that hydraulic oil flows into the annular step 432 and the oil inlet gap 433 during operation. The radial force of the hydraulic oil makes the sealing ring tightly adhere to the inner wall of the sealing ring groove 43, and the axial force enhances the fit between the sealing ring and the hydraulic plate and the cover 4, forming a "system pressure self-driven seal". The sealing effect is strengthened synchronously with the increase of system oil pressure, realizing dynamic compensation for wear.

[0036] Radial sealing principle: When a pressure difference is formed in the pump chamber 20 and the outlet swing gap 105 of the separating component is opened, the outer wall of the upper swing member 102 abuts against the inner teeth of the external gear 2 to achieve a seal; the outer wall of the lower swing member 103 abuts against the outer teeth of the internal gear 3 to separate the oil inlet side (low-pressure chamber) and the oil outlet side (high-pressure chamber) of the pump chamber 20. At the same time, the outlet swing gap 105 (high-pressure chamber spacing) is greater than the inlet swing gap 104 (low-pressure chamber spacing) to ensure that the sealing position of the upper and lower swing members and the intermediate shaft remains stable, forming a radial sealing system in the gear pump chamber. This sealing principle is achieved by the system pressure itself. The sealing effect is strengthened synchronously with the increase of system oil pressure, and wear dynamic compensation is achieved at the same time.

[0037] Clearance fit principle: By setting an asymmetrical structure where the outlet swing clearance 105 is larger than the inlet swing clearance 104, the system's own oil pressure difference drives the swing component to automatically offset and press against the intermediate shaft 101, forming a dynamic, adaptive pressure-enhanced seal. This seal can self-lock under the action of high-pressure oil, thereby effectively isolating high and low pressure areas, reducing internal leakage, and ultimately improving pump efficiency.

[0038] Hydraulic flow principle: The size design of hydraulic inlet 62 and hydraulic outlet 63 (with an area larger than the corresponding area of ​​pump chamber 20) and arc-shaped structure ensure smooth hydraulic oil flow and reduce pressure loss; the symmetrical arrangement of inlets and outlets ensures uniform distribution of hydraulic force and guarantees stable operation of the structure.

[0039] Friction reduction and heat dissipation principle: The first cooling tank 66, the second cooling tank 67 and the third cooling tank 68 increase the heat dissipation area. The hydraulic oil circulates in the tanks, efficiently carrying away the heat generated by friction and operation, and avoiding the impact of high temperature on the performance of seals and hydraulic oil.

[0040] Two-way sealing optimization (when the second hydraulic plate 9 is set): The second hydraulic plate 9 and the first hydraulic plate 6 are symmetrically set on both sides of the gear set to achieve two-way end face sealing, completely blocking the leakage path on both sides, while balancing the force on the gear set and reducing uneven wear and mechanical loss.

[0041] Lightweight principle: Based on the improvement of overall pump efficiency, a smaller motor and a smaller housing are used to indirectly reduce the total weight of the gear pump; the axial through-hole 21 on the external gear 2 reduces the weight of the gear without affecting the structural strength and transmission performance, thereby achieving overall lightweighting of the gear pump.

[0042] In the description of the embodiments of this application, it should be noted that the terms "inner" and "outer" and other terms indicating direction or positional relationship are based on the direction or positional relationship shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this application.

[0043] In the description of this application, the references to terms such as "an embodiment," "some embodiments," "in this embodiment," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0044] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A pressure-type self-sealing gear pump, comprising a housing (1), a gear set, a cover (4), and a rotating shaft (5), wherein the housing (1) is provided with a mounting groove (11), the gear set is installed in the mounting groove (11), the gear set includes an internal gear (3) connected to the rotating shaft (5) and an external gear (2) eccentrically arranged and rotatably connected to the external gear (3), the external teeth of the internal gear (3) and the internal teeth of the external gear (2) enclose to form a pump chamber (20), the cover (4) is detachably connected to the mounting groove (11) and axially limits the gear set in the mounting groove (11), the cover (4) is provided with an oil inlet (41) and an oil outlet (42) communicating with the pump chamber (20), one end of the rotating shaft (5) passes through the bottom (112) of the housing groove (11) and is connected to the stator assembly (12) in the housing (1), and the other end of the rotating shaft (5) is rotatably connected to the cover (4), characterized in that, It also includes a first hydraulic plate (6), a first sealing ring (7), and a second sealing ring (8); a partition component (10) is provided in the pump chamber (20) to separate the pump chamber (20) into an oil inlet area and an oil outlet area; the first hydraulic plate (6) is axially limited between the end face of the gear set and the end face of the cover (4); the first hydraulic plate (6) is provided with a shaft hole (61) for the shaft (5) to pass through, a hydraulic inlet (62) connecting the pump chamber (20) and the oil inlet (41), and a hydraulic outlet (63) connecting the pump chamber (20) and the oil outlet (42); the first sealing ring (7) and the second sealing ring (8) are both axially abutted between the end face of the first hydraulic plate (6) and the end face of the cover (4); the hydraulic inlet (62) is sealed and surrounded by the first sealing ring (7); and the hydraulic outlet (63) is sealed and surrounded by the second sealing ring (8).

2. The pressure-type self-sealing gear pump according to claim 1, characterized in that, The separation assembly (10) includes an intermediate shaft (101), an upper swing member (102), and a lower swing member (103); the intermediate shaft (101) is axially mounted on the pump chamber (20), and the upper swing member (102) and lower swing member (103) are respectively sleeved on the upper and lower sides of the intermediate shaft (101) and rotate in cooperation with the intermediate shaft (101); an inlet swing gap (104) is provided between the upper swing member (102) and the lower swing member (103) on the side of the intermediate shaft (101) near the oil inlet (41). An outlet swing gap (105) is provided between the upper swing member (102) and the lower swing member (103) on the side near the oil outlet (42), and the spacing width of the outlet swing gap (105) is greater than the spacing width of the inlet swing gap (104). When a pressure difference is formed in the pump chamber (20) to open the outlet swing gap (105), the outer wall of the upper swing member (102) abuts against the inner teeth of the external gear (2) to achieve a seal; the outer wall of the lower swing member (103) abuts against the outer teeth of the internal gear (3) to separate the oil inlet side and the oil outlet side of the pump chamber (20).

3. The pressure-type self-sealing gear pump according to claim 2, characterized in that, The first hydraulic plate (6) is provided with a first positioning hole (64) that is axially positioned and engaged with the intermediate shaft (101). The cover (4) is provided with a first positioning groove (44) on the end face near the first hydraulic plate (6). One end of the intermediate shaft (101) passes through the first positioning hole (64) and is axially inserted into the first positioning groove (44). The intermediate shaft (101) and the first positioning groove (44) are positioned and engaged to achieve circumferential positioning.

4. The pressure-type self-sealing gear pump according to claim 1 or 2, characterized in that, A sealing ring groove (43) is provided on the end face of the cover (4) near the first hydraulic plate (6), and the opening of the sealing ring groove (43) faces the first hydraulic plate (6). The bottom (431) of the sealing ring groove (43) is provided with an annular step (432) in the circumferential direction, and the annular step (432) is close to the inner peripheral wall of the sealing ring groove (43). The second sealing ring (8) is disposed in the sealing ring groove (43) and covers the outside of the annular step (432). An oil inlet space communicating with the annular step (432) is formed between the inner peripheral wall of the second sealing ring (8) and the inner peripheral wall of the sealing ring groove (43). During operation, hydraulic oil flows into the annular step (432) through the inlet gap (433), and under the action of oil pressure, the hydraulic oil in the inlet gap (433) acts radially on the inner peripheral wall of the second sealing ring (8), and the hydraulic oil in the annular step (432) acts axially on the end face of the second sealing ring (8) near the cover (4); the outer end face (435) of the cover (4) located in the sealing ring groove (43) is higher than the inner end face (434) of the cover (4) located in the sealing ring groove (43), so that the outer end face (435) and the inner end face (434) form a step difference to facilitate the entry of hydraulic oil.

5. The pressure-type self-sealing gear pump according to claim 4, characterized in that, The hydraulic inlet (62) and hydraulic outlet (63) are arranged on both radial sides of the shaft hole (61) and are both arc-shaped, with the openings of the hydraulic inlet (62) and hydraulic outlet (63) facing the shaft hole (61); the middle of the hydraulic inlet (62) and hydraulic outlet (63) are provided with radially distributed reinforcing ribs (65); the second sealing ring (8) and the first sealing ring (7) are symmetrically arranged on both radial sides of the shaft hole (61), and the sealing structures of the second sealing ring (8) and the first sealing ring (7) are the same.

6. The pressure-type self-sealing gear pump according to claim 4, characterized in that, The cross-sectional area of ​​the hydraulic inlet (62) is greater than the cross-sectional area of ​​the oil inlet area (201) of the pump chamber (20), and the cross-sectional area of ​​the hydraulic outlet (63) is greater than the cross-sectional area of ​​the oil outlet area (202) of the pump chamber (20); the oil pressure area S1 on the end face of the first hydraulic plate (6) near the gear set is less than the oil pressure area S2 on the end face of the first hydraulic plate (6) away from the gear set.

7. The pressure-type self-sealing gear pump according to claim 6, characterized in that, The first hydraulic plate (6) has at least one lubrication groove on the end face near the gear set to reduce friction.

8. The pressure-type self-sealing gear pump according to claim 7, characterized in that, The first hydraulic plate (6) is provided with a first cooling groove (66) and a second cooling groove (67) on the end face near the gear set. The first cooling groove (66) and the second cooling groove (67) are located on the radial sides of the shaft hole (61). The first cooling groove (63) is located on the radial outer side of the hydraulic inlet (62) and corresponds to the oil inlet area of ​​the gear set. The second cooling groove (64) is located on the radial outer side of the hydraulic outlet (63) and corresponds to the oil outlet area of ​​the gear set.

9. The pressure-type self-sealing gear pump according to claim 1, characterized in that, The housing (1) has an annular mounting cavity (13) for mounting the stator assembly (12) circumferentially arranged inside, and a support part (14) is protruding in the middle of the annular mounting cavity (13) on the housing (1). A bearing hole is axially arranged through the center of the support part (14). The rotating shaft (5) is axially inserted in the bearing hole and is rotatably connected to the bearing hole through the first bearing (51). A number of heat-conducting connecting ribs (15) are evenly distributed circumferentially inside the annular mounting cavity (13). One radial end of each heat-conducting connecting rib (15) is connected to the outer wall of the support part (14), and the other radial end of the heat-conducting connecting rib (15) is connected to the inner wall of the outer side of the housing (1).

10. The pressure-type self-sealing gear pump according to claim 1, characterized in that, It also includes a second hydraulic plate (9), which has the same structure as the first hydraulic plate (6) and is symmetrically arranged on both sides of the gear set axial end face, and the second hydraulic plate (9) is axially limited between the gear set and the bottom (112) of the housing groove of the mounting groove (11).

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