A plunger pump integrated positioning seal flange structure, a swash plate plunger pump comprising the flange structure and an assembling method

Abstract

The application belongs to the technical field of hydraulic transmission core elements, and specifically discloses a plunger pump integrated positioning sealing flange structure, a plunger pump comprising the flange structure and an assembling method, wherein the three major core functions of positioning of a double-tapered roller bearing, assembly alignment of a swash plate shaft and high-pressure sealing of a shaft end are integrated by means of the integrated design of the positioning sealing flange, so that the technical defects of poor assembly coaxiality, weak shaft center dynamic balance capability, insufficient shaft end sealing reliability and low assembly and maintenance efficiency in the prior art are fundamentally solved, and the working performance and service life of the swash plate plunger pump under high-pressure heavy-load working conditions are improved.

Description

Technical Field

[0001] This invention relates to the field of hydraulic transmission core component technology, specifically to an integrated positioning and sealing flange structure for a plunger pump that integrates shaft balancing, assembly positioning, and high-pressure sealing functions, a plunger pump including the flange structure, and an assembly method thereof, which is particularly suitable for high-pressure and heavy-load working conditions such as marine engineering and heavy engineering machinery. Background Technology

[0002] As the power core of a hydraulic system, the performance of a swashplate axial piston pump highly depends on the dynamic stability of the swashplate shaft, the assembly precision of the moving parts, and the reliability of the medium seal. Existing swashplate piston pumps generally employ a split structure for swashplate shaft support, assembly positioning, and shaft end sealing. This double tapered roller bearing support layout has significant technical shortcomings: the bearing positioning references are dispersed between the pump body and independent parts, requiring repeated adjustments during assembly. Reference conversion easily leads to cumulative errors, making it difficult to guarantee the coaxiality and operational accuracy of the swashplate shaft. This, in turn, exacerbates the uneven wear of key moving parts such as the piston, cylinder, and slipper, reducing the pump's volumetric efficiency. Simultaneously, the split positioning components lack sufficient rigidity to counteract the periodic axial and radial forces generated by the piston's reciprocating motion and the slipper's action. This fails to effectively constrain the dynamic movement and yaw of the swashplate shaft, resulting in increased pump vibration and noise. In heavy-load vibration environments such as marine engineering, this can easily lead to premature bearing failure.

[0003] Furthermore, in the existing structure, the installation reference for the seal and the positioning reference for the bearing are independent. The tightening force of the threaded clamping ring easily causes the lip seal to deviate. The lack of integrated reference constraint results in a high risk of shaft end leakage under high-pressure conditions, and further reduces reliability in marine salt spray environments. Positioning, sealing, and bearing clamping functions are implemented by multiple components, leading to cumbersome assembly processes, high reliance on manual experience, and a high risk of disrupting the original coaxiality and sealing state during later maintenance and disassembly / reassembly, causing pump performance degradation. Therefore, there is an urgent need for an integrated swashplate piston pump with an integrated positioning and sealing flange as its core, capable of simultaneously achieving precise positioning of dual bearings, swashplate shaft center balance constraint, and reliable shaft end sealing, thus structurally solving the existing technical bottlenecks.

[0004] Chinese Patent (Grant Announcement No. CN114776578B, Grant Announcement Date 20250801) discloses a leak-proof internal circulation plunger pump. Through a split-type inlet chamber design of the pump body and pump cover, combined with the flow layout of the booster chamber and outlet chamber, a return channel is added. A sealing assembly consisting of a high-pressure water seal, a low-pressure water seal, and a sealing ring is installed in the booster chamber, forming an internal circulation channel between the return chamber A, return chamber B, and the return channel. This allows the medium leaking between the booster chamber and the sealing assembly to circulate internally. The flow channel returns to the pressurization chamber, preventing the medium from leaking out under high-pressure conditions of the plunger pump. This improves the sealing reliability of the plunger pump and ensures that leaked medium will not affect the normal use of the equipment. However, it still has problems such as easy wear of sealing components and easy flow resistance in the circulation channel under high-pressure conditions. Furthermore, its structural design is only suitable for low-pressure water medium transportation scenarios in cleaning machines, which has a narrow range of applications. It is difficult to meet the sealing requirements of ultra-high pressure hydraulic conditions while simultaneously improving the wear resistance of sealing components and achieving low-energy flow in the internal circulation channel. Summary of the Invention

[0005] To address the technical problems existing in the prior art, the core objective of this invention is to provide an integrated positioning and sealing flange structure for a plunger pump, a swashplate plunger pump including the flange structure, and an assembly method thereof. Through the integrated positioning and sealing flange design, the invention integrates three major functions: positioning of the double tapered roller bearing, alignment of the swashplate shaft assembly, and high-pressure sealing at the shaft end. This solves the problems of poor coaxiality, imbalance, unreliable sealing, and complex assembly in the prior art. Simultaneously, it optimizes the assembly coordination of various components, improving the reliability and service life of the pump body under high-pressure and heavy-load conditions.

[0006] To solve the above problems, the following solution is adopted: Firstly, the present invention provides an integrated positioning and sealing flange structure for a plunger pump, which is an integrally forged annular structure that integrates a flange mounting part, a sealing mounting part, a rigid balance support part, and a swashplate shaft positioning hole arranged coaxially. The rigid balance support is an annular rib structure, with an outer tapered roller bearing positioning step formed at one end; the inner ring at the other end forms the sealing mounting part; the inner ring of the sealing mounting part is provided with a lip-shaped sealing mounting groove and a retaining ring mounting groove. The flange mounting part is located on the outer ring of the rigid balance support part, and bolt connection holes are evenly distributed along the circumference of the flange mounting part. The end face of the flange mounting part that fits against the pump body is the flange mounting reference surface; a static sealing gasket mounting groove is opened on the flange mounting reference surface.

[0007] Furthermore, a grease reservoir is formed at the connection point between the end of the rigid balance support and the end of the sealing mounting part.

[0008] Furthermore, the positioning sealing flange is made of high-strength alloy steel, which, after quenching and tempering, possesses high rigidity and fatigue resistance.

[0009] Furthermore, the surface roughness of the hole wall of the positioning hole of the outer tapered roller bearing meets the requirements for precision fit, so as to ensure the fitting accuracy with the outer ring of the outer tapered roller bearing.

[0010] Furthermore, the bottom end face of the lip seal mounting groove is perpendicular to the central axis of the flange to ensure the installation accuracy and sealing reliability of the lip seal.

[0011] Furthermore, the outer surface of the positioning sealing flange and the bolt connection holes are treated with anti-corrosion measures; Furthermore, the sealing mounting groove undergoes surface hardening treatment to improve wear resistance and corrosion resistance.

[0012] Furthermore, the positioning sealing flange integrates the dual bearing positioning reference, sealing installation reference, and installation reference surface into one through an integrated coaxial structure design, thereby ensuring the assembly coaxiality of the swashplate shaft and the pump body, and maintaining the dynamic axial balance of the swashplate shaft.

[0013] Secondly, the present invention also provides a swashplate piston pump, including the piston pump integrated positioning and sealing flange structure described above.

[0014] As a further technical solution, it also includes a pump body, swashplate shaft, lip seal, threaded clamping ring, outer tapered roller bearing, inner tapered roller bearing, pump body, plunger, slipper, return plate, and deep groove ball bearing. The outer tapered roller bearing and the inner tapered roller bearing are installed between the swashplate shaft and the pump body; The outer ring end face of the outer tapered roller bearing is in contact with the positioning step of the outer tapered roller bearing; the inner ring of the outer tapered roller bearing is interference-fitted to the outer shaft section of the swashplate shaft; The lip seal is installed in the lip seal mounting groove, the threaded clamping ring is screwed into the threaded clamping mating section of the swashplate shaft and axially pre-tightens the lip seal; the positioning sealing flange is fixed to the pump body by bolts; the end of the swashplate shaft is equipped with a return plate and a slipper, the slipper is connected to the plunger ball joint, and the deep groove ball bearing is assembled inside the pump body.

[0015] As a further technical solution, the pump casing is provided with inner and outer bearing seat positioning holes and flange assembly reference surfaces.

[0016] Thirdly, based on the aforementioned swashplate piston pump, the present invention provides an assembly method for the swashplate piston pump, as detailed below: The inner ring of the inner tapered roller bearing is interference-fitted onto the inner shoulder of the swashplate shaft, completing the pre-assembly of the tapered roller bearing and the swashplate shaft. Then, the outer rings of the outer and inner tapered roller bearings are fitted into the inner and outer bearing housing positioning holes of the pump housing, ensuring an interference fit between the two bearing outer rings and the bearing housing positioning holes. The pump housing with the bearing outer rings installed is then assembled onto the swashplate shaft. Subsequently, the inner ring of the outer tapered roller bearing is fitted onto the outer shaft section of the swashplate shaft, and the threaded clamping ring is screwed on to apply axial preload to the end face of the inner ring of the outer tapered roller bearing, ensuring that the inner and outer rings of the two tapered roller bearings initially fit together, completing the initial alignment of the swashplate shaft. A lip seal is embedded in the lip seal mounting groove, and a retaining ring is installed in the retaining ring mounting groove to restrict the axial displacement of the lip seal. The static sealing ring is embedded in the static sealing gasket mounting groove of the positioning sealing flange, and the positioning sealing flange is fitted onto the swashplate shaft through the positioning hole of the swashplate shaft. The positioning sealing flange is fixed to the pump body by bolts passing through the bolt connection holes of the flange mounting end, ensuring that the positioning step of the outer tapered roller bearing is in close contact with the end face of the outer ring of the outer tapered roller bearing, applying axial preload to the bearing, and ensuring that the mounting reference surface is in close contact with the flange assembly reference surface. Thus, under the action of the positioning sealing flange and the two bearings, the three-point precise positioning of the swashplate shaft is achieved, ensuring the coaxial assembly of the swashplate shaft and the pump body. Finally, a return plate and slipper are installed at the end of the swashplate shaft, and the slipper is connected to the plunger ball joint. The deep groove ball bearing is installed inside the pump body to support the plunger cylinder, thus completing the assembly of the entire machine.

[0017] Compared with the prior art, the advantages and positive effects of this invention are: (1) Compared with the prior art, the present invention has achieved significant improvements in assembly accuracy and dynamic balance performance of the shaft, effectively solving the core structural defects of traditional swashplate axial piston pumps. The present invention integrates the positioning and sealing flange into a single structure by setting the flange mounting reference surface, the sealing mounting part, and the positioning step of the outer tapered roller bearing. This integrates the positioning reference of the double tapered roller bearing, the lip seal mounting reference, and the pump body mounting reference, completely eliminating the reference conversion error present in the split structure. It accurately ensures the coaxiality of the swashplate shaft and the pump body, significantly reduces the risk of uneven wear of key moving parts such as the piston, slipper, and cylinder, and significantly improves the volumetric efficiency of the pump body. At the same time, the high-rigidity rigid balance support on the positioning and sealing flange can work synergistically with the positioning constraint of the double tapered roller bearing to effectively counteract the periodic axial force generated by the reciprocating motion of the piston and the radial component force brought by the contact of the slipper. This provides reliable constraint on the dynamic movement and sway of the swashplate shaft, significantly reducing the vibration and noise of the pump body during operation and effectively extending the service life of the bearings and the whole machine.

[0018] (2) This invention also achieves breakthrough improvements in sealing reliability and assembly and maintenance efficiency, greatly enhancing the equipment's adaptability to operating conditions and ease of use. Relying on the integrated sealing reference of the positioning sealing flange, the installation force of the lip seal is more uniform, allowing the pump body to maintain a stable and reliable sealing effect under high pressure conditions and harsh working environments, significantly reducing the risk of medium leakage at the shaft end; at the same time, the integrated design of the positioning sealing flange greatly reduces the number of overall parts of the pump body, simplifies the assembly process, reduces the reliance on manual experience in the assembly process, and the integrated reference structure also makes the disassembly and reassembly operations of later maintenance easier, and is less likely to damage the original coaxiality and sealing performance of the pump body, effectively avoiding the performance degradation problem after equipment maintenance, and improving the stability of the equipment throughout its entire life cycle. Attached Figure Description

[0019] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0020] Figure 1 This is a cross-sectional schematic diagram of the swashplate plunger pump shaft balancing device in Embodiment 1 of the present invention.

[0021] Figure 2 This is a cross-sectional schematic diagram of the axial positioning end cap in Embodiment 1 of the present invention.

[0022] Figure 3 This is a schematic diagram of the installation of the shaft positioning end cap in Embodiment 1 of the present invention.

[0023] Figure 4 This is a schematic diagram of the swashplate plunger pump and shaft positioning end cover in Embodiment 1 of the present invention.

[0024] In the diagram, 1. Swashplate shaft; 2. Lip seal; 3. Positioning sealing flange; 4. Threaded clamping ring; 5. External tapered roller bearing; 6. Internal tapered roller bearing; 7. Pump housing; 8. Piston; 9. Slipper; 10. Return disc; 11. Deep groove ball bearing; 12. Retaining ring; 13. Static seal ring; 31. Flange mounting section; 311. Flange mounting reference surface; 312. Static gasket mounting groove; 32. Swashplate shaft positioning hole; 33. Sealing mounting part; 331. Lip seal mounting groove; 332. Retaining ring mounting groove; 34. Rigid balance support; 35. Locating step for external tapered roller bearings; 36. Grease storage tank; 701. Bearing housing positioning hole; 702. Flange assembly reference surface; Detailed Implementation It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0025] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. Example 1 As a core power component of hydraulic systems, the dynamic stability of the swashplate shaft, the assembly accuracy of the moving parts, and the reliability of the shaft end seal directly determine the overall performance of the swashplate axial piston pump. Existing technologies use a split structure to support, position, and seal the swashplate shaft, which suffers from problems such as large reference conversion errors, weak shaft balance capability, easy seal leakage, and cumbersome assembly and maintenance. Based on this, this embodiment provides a piston pump integrated positioning and sealing flange structure. The integrated forged positioning and sealing flange integrates four functions: dual bearing positioning, shaft end sealing, pump body installation, and shaft balance, eliminating the cumulative reference error of the split structure and ensuring the coaxiality of the swashplate shaft and pump body assembly. Relying on the high-rigidity annular rib structure and the constraint effect of double tapered roller bearings, the axial force and radial component force during hydraulic operation are offset, maintaining the dynamic shaft balance of the swashplate shaft. The integrated sealing reference ensures the installation accuracy of the lip seal, and the continuous grease supply structure reduces seal wear and improves the reliability of the shaft end seal. At the same time, it simplifies the assembly process and reduces the risk of damage to the original precision during maintenance.

[0026] Specifically, the positioning sealing flange 3 provided in this embodiment is as follows: Figure 2 As shown, it is an integrated forged ring structure, integrating a flange mounting part 31, a swashplate shaft positioning hole 32, a sealing mounting part 33, a rigid balance support part 34, and an outer tapered roller bearing positioning step 35, all coaxially arranged. The flange mounting part 31 is located on the outer ring of the rigid balance support part 34. Bolt connection holes are evenly distributed along the circumference of the flange mounting part 31. The bolt connection holes are rigidly connected to the pump casing 7 by bolts. The end face of the flange mounting part 31 that fits with the pump casing 7 is a precision-machined flange mounting reference surface 311. The reference surface has a static sealing gasket mounting groove 312. A compression static sealing ring 13 is installed in the static sealing gasket mounting groove 312. The static sealing fit between the sealing flange 3 and the pump casing 7 is achieved by compressing the static sealing ring 13. The sealing mounting part 33 is located in the inner ring of the rigid balance support part 34. The inner ring of the sealing mounting part 33 is provided with a lip seal mounting groove 331 and a retaining ring mounting groove 332. The lip seal 2 is embedded in the sealing mounting groove 331, and the retaining ring 12 is built into the retaining ring mounting groove 332 to achieve axial positioning of the lip seal 2. The swash plate shaft positioning hole 32 is located in the inner ring of the rigid balance support part 34, ensuring the initial support positioning of the swash plate shaft 1 and ensuring the concentric positioning of the inner ring structure of the outer tapered roller bearing 5 and the inner tapered roller bearing 6. The positioning step 35 of the outer tapered roller bearing fits tightly with the tapered roller bearing 6 to ensure the concentric positioning of the outer ring of the bearing, and achieves double support positioning of the swashplate shaft 1 with the positioning hole 32 of the swashplate shaft. The rigid balance support 34 is an annular stiffener structure that provides high rigidity support for the positioning sealing flange 3, thereby enabling the transmission and offset of external forces.

[0027] Furthermore, in this embodiment, the outer surface of the positioning sealing flange 3 and the bolt connection holes are treated with anti-corrosion measures, and the lip seal mounting groove is treated with surface hardening to improve the wear resistance, corrosion resistance and structural service life of the positioning sealing flange 3.

[0028] Furthermore, the positioning sealing flange 3 is made of high-strength alloy steel in one piece forging. After quenching and tempering, it has high rigidity and fatigue resistance and can withstand periodic external force impacts under high pressure conditions. Furthermore, the bottom end face of the lip seal mounting groove is perpendicular to the central axis of the flange to ensure the installation accuracy and sealing reliability of the lip seal.

[0029] Furthermore, the perpendicularity tolerance between the mounting reference surface of the flange installation part and the center axis of the positioning sealing flange 3 is IT5 grade, which ensures the assembly coaxiality of the swashplate shaft 1 from the perspective of structural accuracy. Furthermore, a grease reservoir 36 can be formed at the connection point between the end of the rigid balance support 34 and the end of the sealing mounting part 33 to provide continuous lubrication for the bearings mounted on the swashplate shaft.

[0030] This embodiment integrates the positioning and sealing flange with the positioning reference, lip seal mounting reference, and pump body mounting reference, completely eliminating the reference conversion error present in the split structure. This ensures the coaxiality of the swashplate shaft and pump body, significantly reducing the risk of uneven wear of key moving parts such as the plunger, slipper, and cylinder, and significantly improving the volumetric efficiency of the pump body. Simultaneously, the high-rigidity annular rib structure on the positioning and sealing flange works synergistically with the positioning constraint of the double tapered roller bearing. This effectively counteracts the periodic axial force generated by the reciprocating motion of the plunger and the radial force from the slipper contact, reliably constraining the dynamic movement and sway of the swashplate shaft. This significantly reduces vibration and noise during pump operation, effectively extending the service life of the bearings and the entire pump.

[0031] Furthermore, relying on the integrated sealing reference of the positioning sealing flange, the installation force of the lip seal is more uniform, allowing the pump body to maintain a stable and reliable sealing effect under high pressure conditions and harsh working environments, significantly reducing the risk of medium leakage at the shaft end. At the same time, the integrated design of the positioning sealing flange greatly reduces the number of overall parts of the pump body, simplifies the assembly process, and reduces the reliance on manual experience in the assembly process. The integrated reference structure also makes disassembly and reassembly operations easier for later maintenance, and is less likely to damage the original coaxiality and sealing performance of the pump body, effectively avoiding the performance degradation problem after equipment maintenance and improving the stability of the equipment throughout its entire life cycle.

[0032] Example 2 In a typical embodiment of the present invention, such as Figures 1-4 As shown, a swashplate piston pump integrating positioning sealing and shaft balancing functions is presented. As a core power component of hydraulic systems, the dynamic stability of the swashplate shaft, the assembly accuracy of the moving parts, and the reliability of the shaft end seal directly determine the overall performance of the swashplate axial piston pump. Existing technologies use a split structure to achieve swashplate shaft support, positioning, and sealing, which suffers from problems such as large reference conversion errors, weak shaft balance capability, easy seal leakage, and cumbersome assembly and maintenance. Based on this, this embodiment provides a swashplate piston pump that integrates positioning, sealing, and shaft balance functions. Through an integrated forged positioning and sealing flange, it integrates four major functions: dual bearing positioning, shaft end sealing, pump body installation, and shaft balance, eliminating the cumulative reference errors of the split structure and ensuring the coaxiality of the swashplate shaft and pump body assembly. Relying on the high-rigidity annular rib structure and the constraint effect of double tapered roller bearings, it offsets the axial and radial forces during hydraulic operation, maintaining the dynamic shaft balance of the swashplate shaft. The integrated sealing reference ensures the installation accuracy of the lip seal, and the continuous grease supply structure reduces seal wear and improves shaft end seal reliability. At the same time, it simplifies the assembly process and reduces the risk of damage to the original precision during maintenance.

[0033] like Figure 1As shown in Figure 2, the swashplate piston pump with integrated positioning, sealing, and shaft balancing functions provided in this embodiment includes a power transmission module, a positioning and balancing module, a sealing and protection module, and a hydraulic actuation module; it can realize high-pressure oil output of the hydraulic system, while ensuring shaft stability and sealing reliability during operation. The positioning and balancing module, with its core positioning and sealing flange 3, is an integrated forged annular structure. Its specific structure is detailed in Example 1 and will not be repeated here. One end of the positioning and sealing flange 3 achieves dual support positioning of the swashplate shaft 1 via an outer tapered roller bearing 5 and an inner tapered roller bearing 6. Precise coaxiality and perpendicularity tolerances ensure the coaxiality of the swashplate shaft 1 and the pump housing 7, eliminating the reference conversion error of the split structure and reducing the risk of uneven wear between the plunger 8 and the cylinder, and between the slipper 9 and the swashplate. The high-rigidity annular rib structure of the rigid balancing support transmits and effectively cancels the periodic axial force generated by the reciprocating motion of the plunger 8 and the radial component force generated by the contact between the slipper 9 and the swashplate to the pump housing 7. Combined with the constraint of the double tapered roller bearings, this restricts the dynamic movement and sway of the swashplate shaft 1, maintains the dynamic axial balance of the swashplate shaft 1, reduces pump vibration and noise, and extends the service life of the bearings and the entire machine.

[0034] Power transmission and hydraulic actuation modules, such as Figure 1 As shown, the swashplate shaft 1 serves as the power input component. Its rotational motion drives the return plate 10 and the slipper 9 to rotate synchronously. The contact between the slipper 9 and the swashplate converts the rotational motion into the reciprocating linear motion of the plunger 8 within the cylinder. When the plunger 8 extends outward, a negative pressure is created in the cylinder, completing the oil suction action. When the plunger 8 retracts inward, the cylinder volume decreases, completing the oil pressure action. Through the continuous reciprocating motion of the plunger 8, a continuous high-pressure oil output is achieved. The deep groove ball bearing 11 provides stable support for the rotation of the plunger cylinder, ensuring the high efficiency of hydraulic conversion.

[0035] The sealing protection module includes a lip seal 2 and a retaining ring 12 that presses against a static sealing ring 13. The lip seal 2 forms a dynamic sealing fit with the swashplate shaft 1 through the axial pre-tightening of the retaining ring 12. The integrated sealing reference of the positioning sealing flange 3 ensures the coaxial installation of the lip seal 2 and avoids lip wear caused by reference offset. The pressing static sealing ring 13 at the flange mounting end achieves a static sealing fit between the positioning sealing flange 3 and the pump body 7. Together with the dynamic sealing structure, it achieves double sealing protection for the pump body, which greatly reduces the risk of medium leakage under high pressure conditions.

[0036] In this embodiment, the swashplate shaft 1 of the power transmission module has a stepped structure, with a return plate 10 and a slipper 9 sequentially mounted at its end. The slipper 9 is ball-jointed to the plunger 8 of the hydraulic actuator module. The deep groove ball bearing 11 is mounted inside the pump housing 7 to provide rotational support for the plunger cylinder. The plunger 8 passes through the plunger hole in the cylinder. The return plate 10 provides preload to the slipper 9 to ensure close contact between the slipper 9 and the swashplate. The rotational motion of the swashplate shaft 1 is converted into the reciprocating linear motion of the plunger 8 through the slipper 9, realizing the oil suction and oil pressure actions of the hydraulic system.

[0037] Furthermore, the pump housing 7 is provided with a bearing seat positioning hole 701 and a flange assembly reference surface 702; the surface roughness of the bearing seat positioning hole 701 meets the precision fit requirements to ensure the fit accuracy with the outer ring of the outer tapered roller bearing 5; furthermore, the surface roughness of the hole wall of the outer tapered roller bearing positioning hole meets the precision fit requirements to ensure the fit accuracy with the outer ring of the outer tapered roller bearing.

[0038] Furthermore, the swash plate shaft 1 is provided with a threaded clamping section. The external thread of the threaded clamping section is a precision thread to ensure the engagement accuracy and uniformity of the preload of the threaded clamping ring. The threaded clamping section is threadedly engaged with the threaded clamping ring 4 to ensure the engagement accuracy and uniformity of the preload of the threaded clamping ring 4. The threaded clamping ring 4 is located above the lip seal 2. When the threaded clamping ring 4 is engaged, an axial preload is applied to the end face of the inner ring of the outer tapered roller bearing 5 to ensure that the inner and outer rings of the two tapered roller bearings are initially fitted together, thus completing the initial alignment of the swash plate shaft 1. In this embodiment, on the swashplate shaft 1, the inner ring of the inner tapered roller bearing 6 is interference-fitted to the inner shoulder of the swashplate shaft 1, and the inner ring of the outer tapered roller bearing 5 is interference-fitted to the outer shaft section of the swashplate shaft 1. The two tapered roller bearings are coaxially positioned by the outer tapered roller bearing positioning step 35 of the positioning sealing flange 3 and the pump housing 7. The positioning sealing flange 3 and the pump housing together constrain the radial offset and axial movement of the swashplate shaft 1.

[0039] like Figure 1 , Figure 3 and Figure 4 As shown, the specific assembly method of the above structure is as follows: During the assembly of the positioning sealing flange 3, firstly, the inner ring of the inner tapered roller bearing 6 is interference-fitted onto the inner shoulder of the swashplate shaft 1, completing the pre-assembly of the tapered roller bearing 6 and the swashplate shaft 1; then, the outer rings of the outer tapered roller bearing 5 and the inner tapered roller bearing 6 are fitted into the inner and outer bearing housing positioning holes 701 of the pump housing 7, ensuring an interference fit between the outer rings of the two bearings and the positioning holes 701 of the bearing housing; the pump housing 7 with the bearing outer rings installed is then assembled onto the swashplate shaft, and subsequently, the outer tapered roller bearing... 5. The inner ring is fitted into the outer shaft section of the swashplate shaft 1. The threaded clamping ring 4 is screwed in to apply axial preload to the end face of the inner ring of the outer tapered roller bearing 5, ensuring that the inner and outer rings of the two tapered roller bearings initially fit together, completing the initial alignment of the swashplate shaft 1. However, since the split bearing is used in this embodiment, slippage can easily occur between the inner and outer rings of the bearing. Therefore, the two bearings alone cannot guarantee that the swashplate shaft 1 will be completely aligned. A lip seal 2 is embedded in the lip seal mounting groove 331, and a retaining ring mounting groove 3 is also included. In section 32, a retaining ring 12 is installed to restrict the axial displacement of the lip seal 2. The static sealing ring 13 is embedded into the static sealing gasket mounting groove 312 of the positioning sealing flange 3. The positioning sealing flange 3 is then fitted onto the swashplate shaft 1 through the positioning hole 32 of the swashplate shaft. The positioning sealing flange 3 is then fixed to the pump housing 7 by bolts passing through the bolt connection holes of the flange mounting end 31. This ensures that the positioning step 35 of the outer tapered roller bearing is in close contact with the outer ring end face of the outer tapered roller bearing 5, applying axial preload to the bearing and ensuring that the mounting reference surface 311 is in close contact with the flange assembly reference surface 702. Thus, under the action of the positioning sealing flange 3 and the two bearings, the three-point precise positioning of the swashplate shaft 1 is achieved, ensuring the coaxial assembly of the swashplate shaft 1 and the pump housing 7. Finally, a return plate 10 and a slipper 9 are installed at the end of the swashplate shaft 1. The slipper 9 is connected to the plunger 8 by a ball joint. The deep groove ball bearing 11 is installed inside the pump housing 7 to support the plunger cylinder. This completes the assembly of the entire machine.

[0040] In summary, this invention employs an integrated positioning seal and shaft balance structure design. Compared to existing technologies, by integrating the dual bearing positioning reference, seal installation reference, and pump body installation reference through the positioning seal flange 3, the cumulative reference error of the split structure is completely eliminated, ensuring the assembly coaxiality and dynamic shaft stability of the swashplate shaft 1. The integrated structure design reduces the number of parts, simplifies the assembly process, reduces reliance on manual experience, and is less likely to damage the original coaxiality and sealing performance during later maintenance disassembly and reassembly, effectively preventing pump performance degradation. At the same time, the continuous grease supply structure improves the wear resistance and sealing reliability of the seals, enabling the pump body to maintain stable working performance under high pressure, heavy load, and harsh working conditions, making it suitable for high-end hydraulic systems in marine engineering, heavy engineering machinery, and other fields.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An integrated positioning and sealing flange structure for a plunger pump, characterized in that, It is an integrated forged ring structure, which integrates a flange mounting part, a sealing mounting part, a rigid balance support part, and a swashplate shaft positioning hole, all arranged coaxially. The rigid balance support is an annular rib structure, with an outer tapered roller bearing positioning step formed at one end; the inner ring at the other end forms the sealing mounting part; the inner ring of the sealing mounting part is provided with a lip-shaped sealing mounting groove and a retaining ring mounting groove. The flange mounting part is located on the outer ring of the rigid balance support part, and bolt connection holes are evenly distributed along the circumference of the flange mounting part. The end face of the flange mounting part that fits against the pump body is the flange mounting reference surface; the flange mounting reference surface has a static sealing gasket mounting groove.

2. The integrated positioning and sealing flange structure for a plunger pump as described in claim 1, characterized in that, The positioning sealing flange is made of high-strength alloy steel, which, after quenching and tempering, possesses high rigidity and fatigue resistance.

3. The integrated positioning and sealing flange structure for a plunger pump as described in claim 1, characterized in that, The bottom end face of the lip seal mounting groove is perpendicular to the center axis of the flange.

4. The integrated positioning and sealing flange structure for a plunger pump as described in claim 1, characterized in that, A grease reservoir is formed at the connection point between the end of the rigid balance support and the end of the sealing installation part.

5. The integrated positioning and sealing flange structure for a plunger pump as described in claim 1, characterized in that, The outer surface of the positioning sealing flange and the bolt connection holes are treated with anti-corrosion measures.

6. The integrated positioning and sealing flange structure for a plunger pump as described in claim 1, characterized in that, The lip seal mounting groove is surface hardened.

7. A swashplate piston pump, comprising the integrated positioning and sealing flange structure of the piston pump according to any one of claims 1-6.

8. The swashplate piston pump as described in claim 7, characterized in that, It also includes the pump body, swash plate shaft, lip seal, threaded clamping ring, external tapered roller bearing, internal tapered roller bearing, pump body, plunger, slipper, return plate, and deep groove ball bearing; The outer tapered roller bearing and the inner tapered roller bearing are installed between the swashplate shaft and the pump body; The outer ring end face of the outer tapered roller bearing is in contact with the positioning step of the outer tapered roller bearing; the inner ring of the outer tapered roller bearing is interference-fitted to the outer shaft section of the swashplate shaft; The lip seal is installed in the lip seal mounting groove, the threaded clamping ring is screwed into the threaded clamping mating section of the swashplate shaft and axially pre-tightens the lip seal; the positioning sealing flange is fixed to the pump body by bolts; the end of the swashplate shaft is equipped with a return plate and a slipper, the slipper is connected to the plunger ball joint, and the deep groove ball bearing is assembled inside the pump body.

9. The swashplate piston pump as described in claim 8, characterized in that, The pump casing is provided with inner and outer bearing seat positioning holes and flange assembly reference surface.

10. The assembly method of the swashplate piston pump as described in claim 9, characterized in that, Specifically as follows: The inner ring of the inner tapered roller bearing is interference-fitted onto the inner shoulder of the swashplate shaft, completing the pre-assembly of the tapered roller bearing and the swashplate shaft. Then, the outer rings of the outer and inner tapered roller bearings are fitted into the inner and outer bearing housing positioning holes of the pump housing, ensuring an interference fit between the two bearing outer rings and the bearing housing positioning holes. The pump housing with the bearing outer rings installed is then assembled onto the swashplate shaft. Subsequently, the inner ring of the outer tapered roller bearing is fitted onto the outer shaft section of the swashplate shaft, and the threaded clamping ring is screwed on to apply axial preload to the end face of the inner ring of the outer tapered roller bearing, ensuring that the inner and outer rings of the two tapered roller bearings initially fit together, completing the initial alignment of the swashplate shaft. A lip seal is embedded in the lip seal mounting groove, and a retaining ring is installed in the retaining ring mounting groove to restrict the axial displacement of the lip seal. The static sealing ring is embedded in the static sealing gasket mounting groove of the positioning sealing flange, and the positioning sealing flange is fitted onto the swashplate shaft through the positioning hole of the swashplate shaft. The positioning sealing flange is fixed to the pump body by bolts passing through the bolt connection holes of the flange mounting end, ensuring that the positioning step of the outer tapered roller bearing is in close contact with the end face of the outer ring of the outer tapered roller bearing, applying axial preload to the bearing, and ensuring that the mounting reference surface is in close contact with the flange assembly reference surface. Thus, under the action of the positioning sealing flange and the two bearings, the three-point precise positioning of the swashplate shaft is achieved, ensuring the coaxial assembly of the swashplate shaft and the pump body. Finally, a return plate and slipper are installed at the end of the swashplate shaft, and the slipper is connected to the plunger ball joint. The deep groove ball bearing is installed inside the pump body to support the plunger cylinder, thus completing the assembly of the entire machine.

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