Floating lining plate device for plunger pump

Abstract

The floating lining plate device for the plunger pump comprises a floating disc and a communicating sleeve, round holes which are evenly distributed are formed in the upper end face of the floating disc, the communicating sleeve is inserted into the round holes, kidney-shaped grooves which are evenly distributed are formed in the lower end face of the floating disc, and the round holes correspond to the kidney-shaped grooves in a one-to-one mode and communicate with the kidney-shaped grooves. The center axes of the circular holes pass through the center points of the corresponding kidney-shaped grooves, every two adjacent kidney-shaped grooves are communicated through a set of combined through holes, each set of combined through holes is composed of a piston hole and an auxiliary hole, the center axes of the piston holes and the auxiliary holes are perpendicular to each other, and the piston holes in each set of combined through holes are communicated with one end of one kidney-shaped groove. The central axis of the piston hole passes through the central point of the kidney-shaped groove, and the auxiliary hole is communicated with one end of the other kidney-shaped groove adjacent to the kidney-shaped groove. Through the design that the bidirectional piston is embedded in the floating lining plate, the integration level of the rotating assembly of the swash plate type plunger pump is improved, the flow backward flowing phenomenon in the flow distribution process is effectively reduced, the output flow and pressure pulsation of the plunger pump are reduced, and vibration and noise reduction in the flow distribution process of the swash plate type plunger pump is achieved.

Description

Technical Field

[0001] The invention relates to a floating lining device for a plunger pump, belonging to the technical field of plunger pumps. Background Art

[0002] Axial piston pumps have the characteristics of high rated pressure, easy flow adjustment, high volumetric efficiency, and compact structure. They are widely used in hydraulic systems in key fields such as aerospace, military weapons, and heavy machinery. With the development of my country's aerospace industry, the requirements for lightweight and integrated aerospace hydraulic systems have been put forward. The end-face distribution type axial piston pump using aviation kerosene medium is an important energy conversion component in aerospace hydraulic equipment. Its life and reliability will be directly related to the overall reliability of aerospace equipment. Compared with traditional hydraulic oil, aviation kerosene has a low kinematic viscosity and strong permeability, which makes the plunger pump more prone to leakage. In addition, due to the particularity of aviation kerosene medium, the noise and structural vibration generated during the flow distribution process of the plunger pump increase, and the cavitation and vibration of the axial piston pump under high-speed and high-pressure conditions are getting worse. If the traditional high-viscosity oil pump structure is used to use kerosene medium, the leakage in the pump will increase significantly, which will not only reduce the efficiency of the plunger pump, but also may cause system failure in severe cases.

[0003] The distribution pair is one of the three key friction pairs in the plunger pump. It is mainly composed of a rotating cylinder and a distribution plate. When the plunger pump is working, the plunger follows the piston pump cylinder to perform a rotating reciprocating motion under the action of the inclined plate, and periodically realizes the oil suction and discharge functions. The original traditional oil pump adopts the movement form of a floating cylinder plus a fixed distribution plate. The cylinder can float up and down along the main shaft spline, and automatically adjust the distribution gap to improve oil film leakage. When this structure uses low-viscosity fluid, the leakage flow at the distribution pair gap is greatly increased, and the volumetric efficiency is sharply reduced. Foreign countries started research on plunger pumps early. Similarly, the United States has been conducting research and development of water-based fluid medium plunger pumps since the 1960s. Subsequently, Germany, Japan, Britain, France, Finland and other countries have joined the competition and have successively released molded plunger pump products.

[0004] Patent CN201220722007.0 (CN203081669U) provides a semi-axial pure water hydraulic axial piston pump, which mainly includes a floating plate, a connecting sleeve, a gasket and an O-ring. The floating plate is an improved design for the structure of the distribution pair for low-viscosity fluids. The original floating cylinder structure is separated into: a cylinder section containing a plunger channel and a cylinder section containing a waist-shaped groove. The former is fixedly connected to the main shaft by interference fit, and the latter is converted into a floating plate. Among them, the connecting sleeve of the floating plate is completely pressed into the cylinder section of the plunger channel. Due to the elasticity of the O-ring, the floating plate has three degrees of freedom relative to the rotating cylinder within a small range, namely axial translation and radial micro-displacement. Under this structure, the movement process relies on the O-ring to achieve the sealing between the floating plate assembly and the plunger channel. The floating plate fine-tunes its posture according to the size of the unbalanced torque it bears to maintain a stable water film contact with the distribution plate. It effectively reduces the leakage of the distribution pair under low-viscosity fluid media and improves the lubrication performance of the distribution pair to a certain extent. However, when this structure is adopted, the stability of the rotating assembly decreases due to the splitting of the original integrated cylinder into two parts, and the vibration and noise generated during the low-viscosity fluid distribution process increase. The reason is that this structure does not change the fluid pressure energy transmission process between the plunger channel and the distribution plate. The working principle of the plunger pump itself determines that its flow and pressure pulsation must exist. How to effectively control the flow and pressure pulsation of the existing floating liner distribution structure is the key to vibration and noise reduction control of the low-viscosity end-distribution inclined plate plunger pump.

[0005] Patent CN200910272425.7 (CN101694211A) provides a valve plate for a plunger pump. The movement of the plunger channel on the valve plate can be simplified as the channel sequentially passing through the low-pressure area - low-pressure transition area - high-pressure area - high-pressure transition area. When the plunger channel enters the low-pressure transition area from the low-pressure transition area, its internal pressure may still maintain the low-pressure state of the oil suction area. When the plunger cavity contacts the high-pressure area at this time, the oil in the high-pressure area will flow back to the low-pressure area through the plunger cavity due to the pressure difference, that is, the oil that should be discharged to the high-pressure area flows back to the low-pressure area. This phenomenon is called flow backflow. Flow backflow reduces the effective output flow of the pump and reduces the volumetric efficiency of the pump. In addition, during the flow backflow process, the oil repeatedly flows between the plunger cavity and the high-pressure area, which aggravates the wear of the internal parts of the plunger pump, resulting in an increase in the output flow and pressure fluctuations of the pump, and a significant increase in the vibration and noise levels, affecting the stability and reliability of the entire hydraulic system. In severe cases, it may cause failure and collapse of sensitive hydraulic components in the hydraulic system, shortening the service life of the hydraulic system. In the design process of the existing distribution plate, in order to reduce the harm of flow backflow, vibration reduction groove structures are opened at the entrance of the waist-shaped groove in the low-pressure area and the entrance of the waist-shaped groove in the high-pressure area along the movement direction of the cylinder body. The vibration reduction groove structure includes vibration reduction hole type, triangular groove type, multi-stage U-shaped groove type, etc., all of which reduce the change of pressure gradient to a certain extent by extending the contact time between the plunger channel and the high-pressure area. However, the impact and vibration caused by the change of pressure gradient in the pump are still large, which puts forward new requirements for vibration reduction and noise reduction of the pump internal structure. Summary of the invention

[0006] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a floating liner device for a plunger pump which improves flow backflow, reduces outlet flow and pressure pulsation, and achieves vibration and noise reduction control of the plunger pump.

[0007] The technical solution of the present invention is as follows: a floating liner device for a plunger pump comprises a floating plate and a connecting sleeve, wherein the upper end surface of the floating plate is provided with evenly distributed circular holes, into which the connecting sleeve is inserted, and the lower end surface of the floating plate is provided with evenly distributed waist-shaped grooves, wherein the circular holes correspond to and are connected with the waist-shaped grooves one by one, wherein the central axis of the circular holes passes through the central point of the corresponding waist-shaped groove, and two adjacent waist-shaped grooves are connected through a group of combined communication holes, wherein each group of combined communication holes is composed of a piston hole and a process hole whose central axes are perpendicular to each other, wherein the piston hole in each group of combined communication holes is connected with one end of a waist-shaped groove, wherein the central axis of the piston hole passes through the central point of the waist-shaped groove, and the process hole is connected with one end of another waist-shaped groove adjacent to the waist-shaped groove; A bidirectional piston and a screw are arranged in the piston hole. The screw seals the bidirectional piston in the piston movement section at the front end of the piston hole. The bidirectional piston can move bidirectionally in the piston movement section.

[0008] The beneficial effects of the present invention compared with the prior art are as follows: (1) The present invention improves the integration of the rotating assembly of the swash plate plunger pump by designing a bidirectional piston embedded in a floating liner, effectively reduces the flow backflow phenomenon during the flow distribution process, reduces the output flow and pressure pulsation of the plunger pump, and achieves vibration reduction and noise reduction during the flow distribution process of the swash plate plunger pump; (2) The bidirectional piston of the present invention adaptively balances the pressure on both sides according to the contact pressure difference between the plunger cavity and the inlet and outlet, thereby reducing vibration and noise, weakening cavitation, and reducing pulsation; (3) The present invention uses a processing channel to communicate adjacent waist-shaped grooves, and cooperates with an inserted bidirectional piston assembly to seal the fluids on both sides, thereby realizing an integrated design of a floating liner base, a piston, and a screw assembly. The structure is compact and the integration is high, thereby improving the dynamic performance and volumetric efficiency of the plunger pump. (4) The present invention has outstanding advantages in end-distribution axial piston pumps using low-viscosity working media such as aviation kerosene, and can also be applied to hydraulic piston pumps using various medium- and high-viscosity mineral oils as working media. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a stereogram of the present invention; Figure 2 It is a side view of the present invention; Figure 3 for Figure 2 AA section view; Figure 4 is a cross-sectional view of a floating liner of the present invention; Figure 5 It is a schematic diagram of the assembly of the present invention, the cylinder body and the valve plate; Figure 6 It is a working schematic diagram of the floating lining plate rotating on the distributor plate of the present invention; Among them, 1. floating plate, 2. connecting sleeve, 3. O-ring, 4. gasket, 5. piston, 6. dynamic seal, 7. screw, 8. plug, 9. waist groove, 10. piston hole, 11. process hole, 12. cylinder body, 13. plunger cavity, 14. distribution plate, 15. plunger cavity A, 16. plunger cavity B, 17. plunger cavity C, 18. low pressure zone, 19. low pressure transition zone, 20. high pressure zone, 21. high pressure transition zone, 22. external stop section, 23. threaded section, 24. fluid communication section, 25. piston movement section. DETAILED DESCRIPTION

[0010] The present invention provides a floating liner device for a plunger pump, comprising a floating plate and a connecting sleeve. The upper end surface of the floating plate is provided with evenly distributed circular holes, the connecting sleeve is inserted into the circular holes, and the lower end surface of the floating plate is provided with evenly distributed waist-shaped grooves, the circular holes correspond to and are connected with the waist-shaped grooves one by one, the central axis of the circular holes passes through the central point of the corresponding waist-shaped groove, two adjacent waist-shaped grooves are connected through a group of combined communication holes, each group of combined communication holes is composed of a piston hole and a process hole whose central axes are perpendicular to each other, the piston hole in each group of combined communication holes is connected with one end of a waist-shaped groove, the central axis of the piston hole passes through the central point of the waist-shaped groove, and the process hole is connected with one end of another waist-shaped groove adjacent to the waist-shaped groove.

[0011] A bidirectional piston and a screw are arranged in the piston hole of the present invention. The screw seals the bidirectional piston in the piston movement section at the front end of the piston hole. The bidirectional piston can move bidirectionally in the piston movement section. The movement direction of the bidirectional piston is determined according to the pressure level in two adjacent waist-shaped grooves communicated by the combined communication hole.

[0012] Furthermore, the piston hole is arranged as a stepped hole, which, from outside to inside, comprises an outer stop section, a thread section, a fluid communication section and a piston movement section.

[0013] Furthermore, the screw is screwed into the piston hole through the outer stop section and is threadedly connected with the threaded section, and the front end of the screw is gap-matched with the fluid communication section of the piston hole.

[0014] Furthermore, the piston hole and the process hole are both located on the circumferential side of the floating plate, the piston hole is connected to the waist-shaped groove of the floating plate, the process hole is connected to another adjacent waist-shaped groove, the piston hole is perpendicular to the central axis of the process hole, and the fluid in two adjacent waist-shaped grooves communicates through the piston hole and the process hole.

[0015] Furthermore, the number of the piston holes and process holes on the floating plate is the same as the number of the waist-shaped grooves, and the central axis of the piston hole passes through the central point of the waist-shaped groove communicating with it.

[0016] Furthermore, the inner surface roughness of the piston moving section of the piston hole reaches Ra0.4 or above, and the shape and position tolerance cylindricality is less than 0.015. Preferably, the piston moving section is matched with a bidirectional piston, the bidirectional piston is surface carburized and nitrided, and a bidirectional dynamic seal is provided in the circumferential direction of the bidirectional piston.

[0017] Furthermore, the fluid communication section of the piston hole maintains a clearance fit with the screw rod, thereby reducing the flow resistance of the fluid.

[0018] Furthermore, the threaded section of the piston hole is connected to the screw, and the front end diameter of the screw is smaller than the diameter of the piston moving section in the piston hole. After assembly, the front end of the screw extends into the moving section of the piston hole, and the extension size is limited to 1 to 3 mm, which limits the movement space of the piston.

[0019] Furthermore, the outer stop section of the piston hole cooperates with the screw rod and is axially limited. The rear end face of the screw rod extends out of the floating plate by less than 5 mm. There is an end face seal at the connection between the screw rod and the outer stop of the piston hole to prevent fluid leakage.

[0020] Furthermore, a plug is provided on the outer side of the process hole and is welded or interference pressed into the process hole.

[0021] Furthermore, the connecting sleeve of the present invention is processed with a step groove in the circumferential direction, and the O-ring and the gasket are coaxially installed in the step groove of the connecting sleeve in sequence.

[0022] Further preferably, the gasket of the present invention is an open circular ring with an oblique cut, and the material is selected as engineering plastic or alloy material according to the pressure grade. The material itself has a certain toughness. In the fully compressed state, the outer diameter of the gasket is 0.05 to 0.15 mm smaller than the inner diameter of the piston hole.

[0023] The following will be combined with the embodiments of the present invention Figures 1 to 6 , the implementation methods of the present invention are described in more detail. Obviously, the described embodiments are only a part of all embodiments of the present invention. Other embodiments directly obtained or associated from the contents disclosed in the present invention by ordinary technicians in this field without creative work are all within the protection scope of the present invention.

[0024] The present example is a vibration-reducing and noise-reducing floating liner device for a plunger pump, as shown in 1, 2, and 3, comprising a floating plate 1, a connecting sleeve 2, an O-ring 3, a gasket 4, a piston 5, a dynamic seal 6, a screw 7, and a plug 9.

[0025] like Figure 1 , 4 As shown, five evenly distributed circular holes 26 are provided on the upper end surface of the floating plate 1, into which the connecting sleeve 2 is inserted by interference fit, and the O-ring 3 and the gasket 4 are coaxially installed in the step groove of the connecting sleeve 2 in sequence.

[0026] like Figure 2 , 3 As shown, five evenly distributed waist-shaped grooves 9 are provided on the lower end surface of the floating plate 1, and two adjacent waist-shaped grooves are connected through the piston hole 10 and the process hole 11. The piston hole 10 is punched along the circumferential side of the floating plate 1 and is connected with the waist-shaped groove on the lower end surface of the floating plate 1. The axis of the process hole 11 is arranged to intersect with the axis of the piston hole 10. The number of piston holes 10 and process holes 11 opened circumferentially on the floating plate 1 is the same as the number of waist-shaped grooves 9.

[0027] like Figure 4 As shown, the piston hole 10 is arranged as a stepped hole, which includes, from the outside to the inside, an outer stop section 22, a threaded section 23, a fluid communication section 24 and a piston motion section 25.

[0028] The inner surface roughness of the piston moving section 25 of the piston hole 10 reaches Ra0.4 or above, and the shape and position tolerance cylindricality is less than 0.015. The piston moving section 25 cooperates with the bidirectional piston 5, the bidirectional piston 5 is subjected to surface carburizing and nitriding treatment, and a bidirectional dynamic seal 6 is provided in the circumferential direction of the bidirectional piston 5.

[0029] The fluid communication section 24 of the piston hole 10 is clearance-matched with the screw 7 to reduce flow resistance.

[0030] The threaded section 23 of the piston hole 10 is connected to the screw rod 7. The front end diameter of the screw rod 7 is smaller than the diameter of the piston moving section in the piston hole 10. After assembly, the front end of the screw rod 7 extends into the moving section of the piston hole 10. The extension size is limited to 1 to 3 mm, which limits the movement space of the piston 5.

[0031] The outer stop section 22 of the piston hole 10 cooperates with the screw 7 and is axially limited. The rear end face of the screw 7 extends out of the floating plate 1 by a circumferential dimension of less than 5mm. There is an end face seal at the connection between the screw 7 and the outer stop section 22 of the piston hole 10 to prevent fluid leakage.

[0032] A plug 9 is provided on the outer side of the process hole 11 and is welded or pressed into the hole.

[0033] The gasket 4 is an open circular ring with an oblique cut. The material is selected to be engineering plastic or alloy material according to the pressure level. The material itself has a certain toughness. In the fully compressed state, the outer diameter of the gasket is 0.05-0.15mm smaller than the inner diameter of the piston hole 10.

[0034] like Figure 5 , 6 As shown, taking the movement process of the waist-shaped groove corresponding to the plunger cavity on the distribution plate 14 as an example, the working principle of the piston 5 in this example to achieve vibration reduction and noise reduction through pre-pressurization and pre-pressure relief is explained.

[0035] Pre-pressurization process: Set the plunger cavity to rotate clockwise, the gray waist-shaped groove on the left is low pressure, and the gray waist-shaped groove on the right is high pressure. Figure 6 The location of the middle plunger cavity A15 is the low-pressure transition area of ​​the distribution plate 14, and the sealing transition area on the opposite side is the high-pressure transition area.

[0036] like Figure 6As shown, when the plunger cavity A15 is located in the low-pressure transition zone of the distribution plate 14, the fluid in the plunger cavity is in a sealed state, and the plunger cavity B16 is located in the high-pressure outlet area of ​​the distribution plate. The pressure of the plunger cavity B16 is high pressure. Due to the pressure difference between the plunger cavity A15 and the plunger cavity B16, the bidirectional piston 5 moves toward the plunger cavity A15 under the action of pressure, compressing the working volume of the plunger cavity A15, and the working pressure of the plunger cavity A15 increases, realizing pre-pressurization. The cylinder body 12 and the floating plate 1 continue to rotate, and the plunger cavity A begins to contact the high-pressure outlet area of ​​the distribution plate 14. Due to the pre-pressurization effect of the piston 5 on the plunger cavity A15, the pressure gradient difference between the plunger cavity A15 and the high-pressure outlet is greatly reduced, the backflow flow is reduced, the pressure and flow pulsation are improved, and the vibration of the body and the amplitude of the fluid noise are reduced.

[0037] Pre-pressure relief process: Set the plunger cavity to rotate counterclockwise, the gray waist-shaped groove on the left is low pressure, and the gray waist-shaped groove on the right is high pressure. Figure 6 The location of the middle plunger cavity A15 is the high-pressure transition area of ​​the distribution plate 14, and the sealing transition area on the opposite side is the low-pressure transition area.

[0038] Contrary to the pre-pressurization process, when the plunger cavity A15 is located in the high-pressure transition zone of the distribution plate 14, the fluid in the plunger cavity is in a sealed state. Due to the existence of gap leakage, the pressure of the plunger cavity A15 is sub-high pressure. The plunger cavity C17 is located in the low-pressure inlet area of ​​the distribution plate, and the pressure of the plunger cavity C17 is low pressure. Due to the pressure difference between the plunger cavity A15 and the plunger cavity C17, the two-way piston 5 moves toward the plunger cavity C under the action of pressure, increasing the working volume of the plunger cavity A15, and the working pressure of the plunger cavity A15 is reduced, realizing pre-pressure relief. The cylinder body 12 and the floating plate 1 continue to rotate, and the plunger cavity A15 contacts the low-pressure inlet area of ​​the distribution plate 14. Due to the pre-pressure relief effect of the movement of the two-way piston 5 on the plunger cavity A15, the pressure gradient between the plunger cavity A15 and the low-pressure inlet is greatly reduced, the vibration amplitude of the machine body is reduced, and the cavitation, cavitation and fluid noise in the plunger cavity are improved.

[0039] Parts of the present invention that are not described in detail are well known to those skilled in the art.

Claims

1. A floating liner device for a plunger pump, characterized in that: It comprises a floating plate and a connecting sleeve, wherein the upper end surface of the floating plate is provided with evenly distributed circular holes, into which the connecting sleeve is inserted, and the lower end surface of the floating plate is provided with evenly distributed waist-shaped grooves, wherein the circular holes correspond to and are connected with the waist-shaped grooves one by one, wherein the central axis of the circular holes passes through the central point of the corresponding waist-shaped groove, and two adjacent waist-shaped grooves are connected through a group of combined communication holes, wherein each group of combined communication holes is composed of a piston hole and a process hole whose central axes are perpendicular to each other, wherein the piston hole in each group of combined communication holes is connected with one end of a waist-shaped groove, wherein the central axis of the piston hole passes through the central point of the waist-shaped groove, and the process hole is connected with one end of another waist-shaped groove adjacent to the waist-shaped groove; A bidirectional piston and a screw are arranged in the piston hole. The screw seals the bidirectional piston in the piston movement section at the front end of the piston hole. The bidirectional piston can move bidirectionally in the piston movement section.

2. A floating liner device for a plunger pump according to claim 1, characterized in that: The piston hole is arranged as a stepped hole, which comprises, from outside to inside, an outer stop section, a thread section, a fluid communication section and a piston movement section.

3. A floating liner device for a plunger pump according to claim 2, characterized in that: The screw is screwed into the piston hole through the outer stop section and is threadedly connected with the threaded section. The front end of the screw is gap-matched with the fluid communication section of the piston hole. The central axis of the process hole is located in the area of ​​the fluid communication section.

4. A floating liner device for a plunger pump according to claim 3, characterized in that: The piston holes and process holes are distributed on the circumferential side of the floating plate, and the number of the piston holes and process holes is the same as the number of the waist-shaped grooves.

5. The floating liner device for a plunger pump according to claim 3, characterized in that: The inner surface roughness of the piston moving section of the piston hole reaches Ra0.4 or above, the shape and position tolerance cylindricality is less than 0.015, and a bidirectional dynamic seal is provided in the circumferential direction of the bidirectional piston.

6. A floating liner device for a plunger pump according to claim 5, characterized in that: The front end diameter of the screw rod is smaller than the diameter of the piston moving section in the piston hole. After assembly, the front end of the screw rod extends into the moving section of the piston hole.

7. A floating liner device for a plunger pump according to claim 6, characterized in that: The outer stop section of the piston hole cooperates with the screw rod, and an end face seal is arranged at the connection between the screw rod and the outer stop section of the piston hole.

8. A floating liner device for a plunger pump according to claim 7, characterized in that: The surface of the bidirectional piston is carburized and nitrided, the front end of the screw extends into the dimension of 1-3mm, the rear end of the screw extends out of the floating plate circumference dimension <5mm, and a plug is provided on the outside of the process hole, which is welded or pressed into the process hole.

9. A floating liner device for a plunger pump according to any one of claims 1 to 8, characterized in that: The connecting sleeve is processed with a step groove in the circumference, and the O-ring and the gasket are coaxially installed in the step groove of the connecting sleeve in sequence.

10. A floating liner device for a plunger pump according to claim 9, characterized in that: The gasket is an open circular ring with an oblique cut, and the material is selected to be engineering plastic or alloy material according to the pressure grade. In the fully compressed state, the outer diameter of the gasket is 0.05-0.15mm smaller than the inner diameter of the piston hole.

Images