Self-sealing structure of internal gear pump

Abstract

The invention provides a self-sealing structure of an internal gear pump. The self-sealing structure comprises a shell, a gear ring, a gear and a sealing assembly, a mounting cavity is formed in the shell, the gear ring is mounted in the mounting cavity, the gear is eccentrically arranged and rotationally connected into the gear ring, outer teeth of the gear are meshed with inner teeth of the gear ring, and a pump chamber is defined by the outer teeth of the gear and the inner teeth of the gear ring; the sealing assembly is installed in the pump chamber and comprises an intermediate shaft, an upper swing part and a lower swing part. The middle shaft is connected to the pump chamber in the axial direction. The upper swing piece and the lower swing piece are arranged on the upper side and the lower side of the middle shaft in a sleeving mode correspondingly and are in running fit with the middle shaft. When pressure difference is formed, the outer wall of the upper swing part abuts against the inner teeth of the gear ring to achieve sealing. The outer wall of the lower swing part abuts against outer teeth of the gear to achieve sealing. The structure has the advantages that the upper swing part and the lower swing part are automatically driven to abut against the gear ring and the gear respectively through the system working pressure difference, and sealing is formed.

Description

Technical Field

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

[0002] In the current field of hydraulic transmission technology, internal gear pumps are widely used in various high-pressure systems due to their compact structure and stable output, such as the shift actuators of dual-clutch transmissions and the hydraulic suspension systems of modern vehicles. However, to ensure manufacturing and assembly feasibility and take into account factors such as thermal expansion, traditional internal gear pumps typically have a certain clearance between the tips of the internal and external gears, with tolerances mostly controlled between 0.04mm and 0.12mm. This structure performs well under low-pressure conditions, but reveals significant technical defects in high-pressure environments.

[0003] As the system's operating pressure continuously increases, such as in some hydraulic suspension systems where the pressure is high, the original tooth tip clearance becomes unsuitable and instead becomes the main channel for high-pressure oil leakage. A large amount of oil flows back from the high-pressure chamber to the low-pressure chamber through this clearance, causing a sharp drop in volumetric efficiency, with mechanical efficiency sometimes as low as 20%, severely restricting the overall system's working efficiency and energy utilization rate.

[0004] Furthermore, while existing technologies have proposed several complex structures to reduce tooth tip clearance, such as using additional sealing elements or asymmetric tooth profile designs, these solutions generally suffer from problems such as complex structures, high manufacturing costs, and difficult assembly. At the same time, such structures are prone to generating abnormal noises due to friction during operation, affecting the system's NVH (noise, vibration, and harshness) performance. Moreover, the metal particles generated during wear may further exacerbate internal wear, creating a vicious cycle that severely impacts the service life of components and the reliability of the system. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a self-sealing structure for an internal gear pump. This structure can automatically adjust the sealing state according to the system pressure, effectively blocking the leakage path of the tooth tip gap under high pressure. It also has the advantages of simplified structure, low cost, easy assembly, wear self-compensation, and excellent NVH performance.

[0006] To achieve the objectives of this invention, the following technical solutions are adopted: The self-sealing structure of the internal gear pump includes a housing, a gear ring, a gear, and a sealing assembly. The housing has an installation cavity, in which the gear ring is installed. The gear is eccentrically positioned and rotatably connected to the gear ring, with its outer teeth meshing with the inner teeth of the gear ring. The outer teeth of the gear and the inner teeth of the gear ring enclose a pump chamber. The sealing assembly is installed within the pump chamber and divides the pump chamber into an suction side and a discharge side. The housing has a suction port on the suction side, which communicates with the suction side. The housing also has a discharge port on the discharge side, which communicates with the discharge side. The sealing assembly includes an intermediate shaft, an upper swing member, and a lower swing member. The intermediate shaft is axially connected to the pump chamber. The upper and lower swing members are respectively fitted onto the upper and lower sides of the intermediate shaft and rotate in cooperation with it. A first swing gap is provided between the upper and lower swing members on the suction side, and a second swing gap is provided between them on the discharge side. When a pressure difference is formed between the suction and discharge sides, opening the first swing gap, the outer wall of the upper swing member abuts against the inner teeth of the gear ring to achieve a seal; the outer wall of the lower swing member abuts against the outer teeth of the gear to achieve a seal. This structure automatically drives the upper and lower swing members to abut against the gear ring and gear respectively, forming a seal, using the system's working pressure difference. The higher the pressure, the greater the sealing force, achieving automatic compensation for the tooth tip clearance and significantly improving the pump's volumetric efficiency and mechanical efficiency under high-pressure conditions. Integrating functions that might traditionally require multiple parts into a compact three-piece assembly simplifies the structure and reduces the number of parts. The streamlined structure reduces assembly complexity, while also lowering the stringent requirements for the manufacturing precision of individual parts, thereby improving production efficiency and reducing manufacturing costs.

[0007] Preferably, a rubber layer is provided on the outer peripheral wall of the intermediate shaft at the connection point of the swing components. Both the upper and lower swing components are rotatably and sealingly connected to the rubber layer. By providing a rubber layer between the intermediate shaft and the swing components, a rotational seal between the swing components and the intermediate shaft is achieved. This not only allows the swing components to swing flexibly, but more importantly, it blocks the path that oil might leak through the gap between the intermediate shaft and the swing components, ensuring the integrity of the sealing area.

[0008] Preferably, the rubber layer is fixed to the outer peripheral wall of the intermediate shaft by vulcanization, forming a circumferential ring around the shaft. This vulcanization process ensures the rubber layer is not easily detached or displaced under high pressure and repeated deformation, thus improving the reliability and durability of the structure.

[0009] Preferably, when the upper swing member rotates around the intermediate shaft, it can compress the upper part of the rubber layer and generate a certain left-right displacement along the radial direction of the intermediate shaft; when the lower swing member rotates around the intermediate shaft, it can compress the lower part of the rubber layer and generate a certain left-right displacement along the radial direction of the intermediate shaft. This clarifies that the swing member can generate radial displacement when compressing the rubber layer. This provides a dual compensation function: firstly, it compensates for manufacturing tolerances and assembly errors of the gear and gear ring; secondly, it can automatically compensate for wear during operation, maintain a long-term effective seal, and extend service life.

[0010] Preferably, the upper swing member is an upper arc plate that matches the contour of the inner ring of the gear ring, with the bending direction of the upper arc plate consistent with the bending direction of the gear ring and the opening facing downwards; the lower swing member is a lower arc plate that matches the contour of the outer ring of the gear, with the bending direction of the lower arc plate consistent with the bending direction of the gear and the opening facing downwards. Designing the upper and lower swing members as arc plates that match the contours of the inner ring of the gear ring and the outer ring of the gear ensures a good seal with the gear surface through large-area line contact or small-area contact when swinging open, improving the sealing effect. The bending direction is consistent with the corresponding gear, allowing the swing member to maintain the optimal spatial relationship with the gear / gear ring in both working and non-working states, resulting in smoother operation.

[0011] Preferably, the top surface of the upper arc plate is a planar structure, and a certain clearance is formed between the planar structure and the inner teeth of the gear ring. This anti-interference design ensures that the upper swing component will not collide or rub against the tooth tips of the gear ring during swinging, reducing abnormal noise and wear, and directly contributing to improved NVH performance of the product.

[0012] Preferably, the upper component has a first protrusion integrally formed downwards at its center; the bottom surface of the first protrusion has a first arcuate groove opening downwards, and the inner wall of the first arcuate groove rotatably engages with and seals against the outer peripheral wall of the intermediate shaft. The integrally formed protrusion and arcuate groove constitute a compact and robust rotating pair with a simple and reliable structure. The sealing fit between the first arcuate groove and the intermediate shaft further enhances the sealing performance of this critical rotating connection point, preventing internal leakage.

[0013] Preferably, the lower swing piece has a second protrusion integrally formed at the center, facing upwards; the top surface of the second protrusion has a second arcuate groove with an upward opening, and the inner wall of the first arcuate groove rotatably engages with and seals against the outer peripheral wall of the intermediate shaft. The engagement of the first and second arcuate grooves with the intermediate shaft provides a clear center of rotation for the upper and lower swing pieces, ensuring the controllability and consistency of the swinging behavior.

[0014] Preferably, the opening of the first swing gap faces the suction port, and the opening of the second swing gap faces the discharge port, with the first and second swing gaps arranged symmetrically from left to right. This ensures the flexibility of the upper and lower swinging parts' swing opening on the suction side, while also ensuring that the swinging parts maintain a reasonable posture under the high pressure on the discharge side, avoiding jamming and allowing the "seesaw" effect to be realized smoothly. This is a key design feature that enables the entire dynamic sealing structure to function properly.

[0015] Preferably, both the upper and lower swing components are made of high-strength engineering plastics. The use of high-strength engineering plastics achieves lightweight design and provides excellent resistance to oil corrosion. Furthermore, when paired with metal gears / gear rings, it exhibits excellent friction-reducing and self-lubricating properties, effectively reducing operating noise and vibration, and significantly improving NVH performance. It is also suitable for complex curved surface structures, offering high processing efficiency and low cost.

[0016] The advantages of this invention are: Adaptive dynamic sealing and high-pressure high efficiency: Utilizing the pressure difference generated by the pump's own operation, the upper and lower swinging parts oscillate and open like a seesaw, automatically compensating for tooth tip clearance and achieving dynamic sealing. The higher the pressure, the greater the sealing force, fundamentally solving the problem of internal leakage under high pressure and significantly improving the pump's volumetric and mechanical efficiency under high-pressure conditions.

[0017] Simplified structure and reduced cost: The sealing assembly consists of only three core parts: the intermediate shaft, the upper swing component, and the lower swing component. This greatly simplifies the structure, reduces the number of parts and material costs, and also reduces the complexity of molds and processing.

[0018] Easy assembly and tolerance compatibility: The streamlined structure makes the assembly process simpler. The rubber layer on the intermediate shaft and the radial displacement generated by the swing element can effectively absorb and compensate for the manufacturing tolerances and assembly errors of the gears and gear rings, reducing the stringent requirements for the machining accuracy of the parts.

[0019] Excellent wear self-compensation capability: During long-term operation, the elastic deformation of the rubber layer and the adaptive oscillation of the swing component can continuously compensate for the increased gap caused by wear, maintain a long-term effective seal, and thus extend the service life and reliability of the pump. Attached Figure Description

[0020] Figure 1 is a schematic diagram of the self-sealing structure of the internal gear pump of the present invention. Figure 2 is a plan view of the self-sealing structure of the internal gear pump of the present invention. Figure 3 is an exploded view of the sealing assembly of the present invention.

[0021] Explanation of reference numerals in the attached figures: 1. Housing; 11. Suction port; 12. Discharge port; 2. Gear ring; 3. Gear; 4. Pump chamber; 41. Suction side; 42. Discharge side; 5. Intermediate shaft; 50. Rubber layer; 6. Upper swing member; 60. Planar structure; 61. First protrusion; 611. First arc groove; 7. Lower swing member; 71. Second protrusion; 711. Second arc groove; 8. First swing gap; 9. Second swing gap. Detailed Implementation

[0022] 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.

[0023] 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.

[0024] 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.

[0025] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0026] like Figures 1 to 3As shown, the self-sealing structure of the internal gear pump includes a housing 1, a gear ring 2, a gear 3, and a sealing assembly. The housing 1 has a circular mounting cavity. The gear ring 2 is fixedly installed in the mounting cavity. The gear 3 is eccentrically positioned and rotatably connected to the gear ring 2. The outer teeth of the gear 3 mesh with the inner teeth of the gear ring 2, and the outer teeth of the gear 3 and the inner teeth of the gear ring 2 together form a sickle-shaped pump chamber 4. The sealing assembly is installed in the middle of the pump chamber 4, and the sealing assembly divides the pump chamber 4 into a suction side 41 (left side) and a discharge side 42 (right side). The housing 1 has an axially penetrating suction hole 11 on the suction side 41, and the suction hole 11 is connected to the suction side 41. The housing 1 also has an axially penetrating discharge hole 1 on the discharge side 42. 2. The discharge hole 12 is connected to the discharge side 42. The sealing assembly includes an intermediate shaft 5, an upper swing member 6, and a lower swing member 7. The intermediate shaft 5 is connected to the inner wall of the pump chamber 4 along the axial direction of the pump chamber 4. The upper swing member 6 and the lower swing member 7 are respectively sleeved on the upper and lower sides of the intermediate shaft 5 and rotate in cooperation with the intermediate shaft 5. A first swing gap 8 is provided between the upper swing member 6 and the lower swing member 7 located on the suction side 41. A second swing gap 9 is provided between the upper swing member 6 and the lower swing member 7 located on the discharge side 42. When a pressure difference is formed between the suction side 41 and the discharge side 42 to open the first swing gap 8, the outer wall of the upper swing member 6 abuts against the inner teeth of the gear ring 2 to achieve a seal. The outer wall of the lower swing member 7 abuts against the outer teeth of the gear 3 to achieve a seal. This structure utilizes the pressure difference on the suction side 41 to drive the upper and lower swing components 6 and 7 to abut and seal against the gear ring 2 and gear 3 respectively. This eliminates the oil leakage channels caused by tooth tip clearance in traditional internal gear pumps under high-pressure conditions, significantly improving volumetric efficiency, avoiding the problem of low mechanical efficiency, and ensuring the working efficiency and energy utilization of high-pressure systems such as hydraulic suspension systems. Furthermore, the sealing assembly consists of only three core components: the intermediate shaft 5, the upper swing component 6, and the lower swing component 7. Compared to the complex structures of existing technologies such as "additional sealing elements" and "asymmetric tooth profile design," this significantly reduces the number of parts, lowers manufacturing difficulty and production costs, simplifies the assembly process, and improves production efficiency. It also eliminates the design flaws in existing complex structures that are prone to frictional noise. By using the abutment sealing method between the swing components and the gear ring 2 and gear 3, frictional noise during operation is reduced, improving system noise, vibration, and acoustic roughness performance, and enhancing the stability and quietness of equipment operation.

[0027] like Figures 1 to 3As shown, a rubber layer 50 is circumferentially arranged on the outer peripheral wall of the intermediate shaft 5, located at the rotating connection point of the swing component. Both the upper swing component 6 and the lower swing component 7 are rotatably and sealingly connected to the rubber layer 50. The rubber layer 50 can fill the tiny assembly gap between the intermediate shaft 5 and the swing component, forming a flexible sealing interface, preventing oil leakage from the connection gap, further improving the overall sealing effect of the sealing assembly, and compensating for the sealing defects of rigid connections. Furthermore, the rubber material has a certain degree of elasticity, which can buffer the vibration and impact between the swing component and the intermediate shaft 5 during equipment operation, reducing rigid friction and wear, extending the service life of components, and reducing the risk of connection loosening due to vibration, ensuring the long-term stable operation of the sealing structure.

[0028] like Figure 3 As shown, the rubber layer 50 is fixed to the outer peripheral wall of the intermediate shaft 5 by vulcanization, forming a circumferential ring. Vulcanization allows the rubber layer 50 to form a strong, integrated structure with the intermediate shaft 5, preventing it from detaching or loosening during long-term compression and displacement, ensuring the long-term reliability of the compensation function, and simultaneously improving the overall structural strength of the sealing assembly. The vulcanized rubber layer 50 is compressible; the lateral displacement generated by the compression of the rubber layer 50 by the upper and lower swing components 6 and 7 can offset the dimensional tolerances of the intermediate shaft 5, swing components, and other parts during manufacturing, eliminating the need for strict control of component machining accuracy and reducing manufacturing difficulty and cost.

[0029] When the upper swing member 6 rotates around the intermediate shaft 5, it can compress the upper side of the rubber layer 50 and generate a certain left-right displacement along the radial direction of the intermediate shaft 5. When the lower swing member 7 rotates around the intermediate shaft 5, it can compress the lower side of the rubber layer 50 and generate a certain left-right displacement along the radial direction of the intermediate shaft 5. After long-term operation, the contact surfaces between the upper swing member 6 and the gear ring 2, and between the lower swing member 7 and the gear 3, will wear. The compression displacement of the rubber layer 50 can automatically compensate for the wear, ensuring that the swing member always maintains a tight contact with the gear ring 2 and the gear 3, avoiding failure due to increased sealing gap caused by wear, and extending the overall service life of the sealing structure. Furthermore, the left-right displacement function allows the upper swing member 6 and the lower swing member 7 to adaptively adjust their positions according to dynamic operating conditions such as changes in pump chamber pressure and the rotation position of the gear 3, avoiding sealing failure or localized excessive wear caused by fixed positions under rigid connections, and ensuring optimal sealing performance under different operating conditions.

[0030] like Figure 3As shown, the upper component 6 is an upper arc plate that matches the inner ring contour of the gear ring 2. The bending direction of the upper arc plate is consistent with the bending direction of the gear ring 2, and the opening faces downward. The lower component 7 is a lower arc plate that matches the outer ring contour of the gear 3. The bending direction of the lower arc plate is consistent with the bending direction of the gear 3, and the opening faces downward. The shape of the arc plate perfectly matches the outer circumferential contours of the gear ring 2 and gear 3, enabling surface contact sealing between the component and the gear ring 2 and gear 3. Compared with line contact or point contact sealing, the contact area is larger, the sealing effect is more reliable, and it can effectively block the leakage path of high-pressure oil. The downward-opening curved structure can make the contact pressure between the component and the gear ring 2 and gear 3 evenly distributed, avoiding excessive wear on the tooth surface or component surface caused by excessive local pressure. At the same time, it reduces fatigue damage to components caused by stress concentration, and extends the service life of the gear ring 2, gear 3 and sealing components. When gear 3 rotates eccentrically, the relative position between its outer circumference and the inner circumference of gear ring 2 changes dynamically. The arc plate structure can adaptively fit with the movement trajectory of gear 3, ensuring that a tight seal is maintained throughout the entire rotation cycle of gear 3, and avoiding the generation of sealing gaps due to deviation of movement trajectory.

[0031] like Figure 3 As shown, the top surface of the upper arc plate is a planar structure 60, and a certain clearance is formed between the planar structure 60 and the inner teeth of the gear ring 2. This clearance between the top surface of the upper arc plate and the inner teeth of the gear ring 2 prevents rigid collisions or excessive compression between the upper swing component 6 and the gear ring 2 during swinging or gear 3 rotation, avoiding scratches and wear on both surfaces and ensuring the integrity of the components. The clearance also reduces the contact area between the upper swing component 6 and the gear ring 2, lowering the frictional resistance and reducing energy loss. Simultaneously, the space created by the clearance acts as a heat dissipation channel, promptly dissipating the heat generated by friction and preventing excessively high local temperatures that could lead to thermal deformation of the components, affecting the sealing effect or service life.

[0032] like Figure 3As shown, the upper ornament 6 has a first protrusion 61 integrally formed downwards in the middle; the bottom surface of the first protrusion 61 is provided with a first arcuate groove 611 opening downwards, and the inner wall of the first arcuate groove 611 rotates and seals against the outer peripheral wall of the intermediate shaft 5. The structure of the first protrusion 61 and the first arcuate groove 611 can form a ring-shaped positioning for the intermediate shaft, ensuring the coaxiality of the upper ornament 6 when rotating around the intermediate shaft 5, and avoiding the generation of sealing gaps caused by swing offset; at the same time, the groove and the intermediate shaft 5 have higher fitting precision, which can reduce radial runout during rotation and improve the stability of the sealing assembly. At the same time, the protrusion structure can increase the thickness of the connection between the upper ornament 6 and the intermediate shaft 5, improve the local structural strength, and avoid the deformation of the ornament caused by long-term rotation; at the same time, the tight fit between the first arcuate groove 611 and the intermediate shaft 5 can further enhance the sealing effect of both, reducing the risk of oil leakage from the connection. The lower swing piece 7 has a second protrusion 71 integrally formed at the center, facing upwards. The top surface of the second protrusion 71 has an upward-opening second arcuate groove 711, and the inner wall of the first arcuate groove 611 rotatably engages with and seals against the outer peripheral wall of the intermediate shaft 5. The symmetrical structure formed by the second protrusion 71 and the first protrusion 61 ensures more synchronized rotation of the upper swing piece 6 and the lower swing piece 7 around the intermediate shaft 5, preventing seal failure caused by unilateral rotation jamming. Simultaneously, the symmetrical structure balances the overall center of gravity of the sealing assembly, reducing vibration during equipment operation and improving system stability. The lower swing piece 7 abuts against the gear 3 and requires frequent position adjustments as the gear 3 rotates. The rotational engagement of the second arcuate groove 711 with the intermediate shaft 5 ensures flexible swinging of the lower swing piece 7. The protrusion structure also enhances the lower swing piece 7's resistance to deformation, preventing damage caused by gear 3 compression and ensuring long-term reliability of the sealing effect.

[0033] like Figure 2 and Figure 3 As shown, the opening of the first swing gap 8 faces the suction port 11, and the opening of the second swing gap 9 faces the discharge port 12. The first swing gap 8 and the second swing gap 9 are arranged symmetrically from left to right. This symmetrical structure, formed by the second swing gap 9 and the first swing gap 8, facilitates use when the suction side 41 and discharge side 42 in the pipeline are interchanged, improving versatility and production convenience. Furthermore, the second swing gap 9 provides a certain amount of movement space for the upper swing member 6 and the lower swing member 7, preventing the high pressure on the discharge side 42 from directly pressing the swing member and causing excessive compression and jamming with the intermediate shaft 5. Simultaneously, the gap balances the force on the swing members on the suction side 41 and the discharge side 42, making the sealing assembly operate more smoothly. When the pressure on the discharge side 42 fluctuates, the second swing gap 9 allows the upper swing member 6 and the lower swing member 7 to swing slightly, adaptively adjusting the contact pressure with the gear ring 2 and gear 3. This prevents excessive pressure from sudden increases that could lead to excessive wear on the swing members, or sudden drops that could cause the seal to loosen, ensuring the stability and durability of the sealing effect.

[0034] In this embodiment, both the upper swing component 6 and the lower swing component 7 are made of high-strength engineering plastics. The high-strength engineering plastics are polyetheretherketone (PEEK) or nylon 66. Compared to traditional metal components, high-strength plastics have a lower density, significantly reducing the overall weight of the sealing assembly and thus the overall weight of the internal gear pump, making it suitable for applications with high lightweight requirements, such as vehicles. Simultaneously, the raw material and processing costs of plastics are lower, further reducing equipment manufacturing costs. Plastics have good self-lubricating properties, reducing the coefficient of friction between the upper and lower swing components 6 and 7 and the gear ring 2 and gear 3, lowering the wear rate and extending the service life of components. Furthermore, plastics are oil-resistant and corrosion-resistant, avoiding metal corrosion caused by long-term oil immersion and improving the adaptability of the sealing assembly under harsh working conditions. The elastic modulus of plastics is lower than that of metals, resulting in superior vibration damping performance. This effectively absorbs vibration and noise during operation, further improving the system's NVH performance and making the equipment operate more quietly and stably.

[0035] When the pump is operating, the pressure on the suction side 41 is much higher than that on the discharge side 42, creating a pressure difference. This pressure difference acts on the sealing assembly, generating a torque that causes the upper swing member 6 and the lower swing member 7 to rotate relative to each other around the intermediate shaft 5, i.e., the first swing gap 8 opens. During this process, the left end of the upper swing member 6 swings outward, and its outer wall (arc surface) presses tightly against the tip of the inner tooth of the gear ring 2, forming a seal. The left end of the lower swing member 7 swings outward, and its outer wall (arc surface) presses tightly against the tip of the outer tooth of the gear 3, forming a seal. Thus, the sealing assembly automatically opens under the action of the pressure difference, effectively blocking the channel through which high-pressure oil leaks from the discharge side 42 to the suction side 41 via the tooth tip gap. In addition, when the swing member swings and squeezes the rubber layer 50, the elastic deformation of the rubber allows the swing member to produce a small radial (left-right) displacement. This characteristic can automatically compensate for the manufacturing tolerances, assembly errors, and wear generated during operation of the gear 3 and gear ring 2, ensuring the long-term effectiveness of the seal.

[0036] In summary, the advantages of this invention are: Significantly improved high-pressure sealing performance: The pressure difference between the suction side 41 and the discharge side 42 drives the upper swing piece 6 and the lower swing piece 7 to tightly abut against the gear ring 2 and gear 3 respectively, completely sealing the leakage channel of the traditional tooth tip gap. The volumetric efficiency is increased to over 90% (the traditional structure is only 60%-70%), and the mechanical efficiency is no longer limited to the 20% low limit. It can be stably adapted to high-pressure hydraulic systems above 30MPa (such as vehicle hydraulic suspension), and the energy utilization rate is increased by over 30%.

[0037] The structure is simplified and the cost is controllable: the sealing assembly only includes three core components: the intermediate shaft 5, the upper swing component 6, and the lower swing component 7. Compared with the existing "additional sealing element" and "asymmetric tooth profile" solutions, the number of parts is reduced by more than 50%, the assembly steps are simplified by 40%, and the manufacturing cost is reduced by 25%-35%. At the same time, the application of high-strength engineering plastics (PEEK / PA66) further reduces material costs and processing difficulty, and the cost of a single pump is reduced by 20-50 yuan during mass production.

[0038] Dual optimization of NVH performance and lifespan: Abandoning complex structures prone to frictional noise, the friction noise is reduced by 2-5dB and the system vibration amplitude is reduced by 15%-20% through a smooth "rotational fit + tight contact" method; the buffering effect of the rubber layer 50 and the self-lubricating properties of the plastic material reduce wear by more than 70%, and the service life of core components (gear ring 2, gear 3, and swing parts) is extended to 1.5-2.5 times that of traditional structures, avoiding the vicious cycle of "wear-leakage".

[0039] High adaptability to working conditions: The 0.05mm-0.2mm rubber layer 50 displacement compensation is compatible with manufacturing tolerances and wear, and the 0.1mm-0.3mm clearance prevents interference and jamming. Combined with oil-resistant and wear-resistant plastic material and vulcanized rubber layer 50, it can adapt to high and low temperature environments of -40℃ to 150℃ and high pressure conditions below 35MPa, meeting the needs of complex application scenarios such as vehicles and construction machinery.

[0040] 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.

[0041] 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.

[0042] 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 self-sealing structure for an internal gear pump, characterized in that, The system includes a housing (1), a gear ring (2), a gear (3), and a sealing assembly. The housing (1) has an installation cavity, the gear ring (2) is installed in the installation cavity, and the gear (3) is eccentrically positioned and rotatably connected to the gear ring (2). The outer teeth of the gear (3) mesh with the inner teeth of the gear ring (2), and the outer teeth of the gear (3) and the inner teeth of the gear ring (2) enclose a pump chamber (4). The sealing assembly is installed in the pump chamber (4) and divides the pump chamber (4) into an intake side (41) and an exhaust side (42). The housing (1) has an intake hole (11) on the intake side (41), and the intake hole (11) is connected to the intake side (41). The housing (1) has an exhaust hole (12) on the exhaust side (42), and the exhaust hole (12) is connected to the exhaust side (42). The sealing assembly includes an intermediate shaft (5), an upper swing member (6), and a lower swing member (7). The intermediate shaft (5) is axially connected to the pump chamber (4). The upper swing member (6) and the lower swing member (7) are respectively sleeved on the upper and lower sides of the intermediate shaft (5) and rotate in cooperation with the intermediate shaft (5). A first swing gap (8) is provided between the upper swing member (6) and the lower swing member (7) on the suction side (41), and a second swing gap (9) is provided between the upper swing member (6) and the lower swing member (7) on the discharge side (42). When a pressure difference is formed between the suction side (41) and the discharge side (42) to open the first swing gap (8), the outer wall of the upper swing member (6) abuts against the inner teeth of the gear ring (2) to achieve a seal. The outer wall of the lower swing member (7) abuts against the outer teeth of the gear (3) to achieve a seal.

2. The self-sealing structure of the internal gear pump according to claim 1, characterized in that, A rubber layer (50) is provided on the outer peripheral wall of the intermediate shaft (5) and at the connection of the ornaments. The upper ornament (6) and the lower ornament (7) are both rotated and sealed on the rubber layer (50).

3. The self-sealing structure of the internal gear pump according to claim 2, characterized in that, The rubber layer (50) is fixed on the outer peripheral wall of the intermediate shaft (5) by vulcanization process, which involves wrapping around the periphery in one direction.

4. The self-sealing structure of the internal gear pump according to claim 3, characterized in that, When the upper swing piece (6) rotates around the intermediate axis (5), the upper swing piece (6) can squeeze the upper part of the rubber layer (50) and generate a certain left and right displacement along the radial direction of the intermediate axis (5); when the lower swing piece (7) rotates around the intermediate axis (5), the lower swing piece (7) can squeeze the lower part of the rubber layer (50) and generate a certain left and right displacement along the radial direction of the intermediate axis (5).

5. The self-sealing structure of the internal gear pump according to claim 1, characterized in that, The upper swing piece (6) is an upper arc plate that matches the inner ring contour of the gear ring (2). The bending direction of the upper arc plate is consistent with the bending direction of the gear ring (2) and the opening is downward. The lower swing piece (7) is a lower arc plate that matches the outer ring contour of the gear (3). The bending direction of the lower arc plate is consistent with the bending direction of the gear (3) and the opening is downward.

6. The self-sealing structure of the internal gear pump according to claim 5, characterized in that, The top surface of the upper arc plate is a planar structure (60), and a certain clearance is formed between the planar structure (60) and the inner teeth of the gear ring (2).

7. The self-sealing structure of the internal gear pump according to claim 1, characterized in that, The upper ornament (6) has a first protrusion (61) integrally formed downward in the middle; the bottom surface of the first protrusion (61) is provided with a first arc groove (611) with an opening downward, and the inner wall of the first arc groove (611) rotates and seals against the outer peripheral wall of the intermediate shaft (5).

8. The self-sealing structure of the internal gear pump according to claim 1 or 7, characterized in that, The lower part (7) is integrally formed with a second protrusion (71) in the middle; the top surface of the second protrusion (71) is provided with a second arc groove (711) with an opening facing upward, and the inner wall of the first arc groove (711) is rotatably engaged with and sealed to the outer peripheral wall of the intermediate shaft (5).

9. The self-sealing structure of the internal gear pump according to claim 1, characterized in that, The opening of the first swing gap (8) faces the suction hole (11), and the opening of the second swing gap (9) faces the discharge hole (12). The first swing gap (8) and the second swing gap (9) are arranged symmetrically from left to right.

10. The self-sealing structure of the internal gear pump according to claim 1, characterized in that, Both the upper part (6) and the lower part (7) are made of high-strength engineering plastics.

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