Plunger for reducing pressure pulsation of axial plunger pump

Abstract

A plunger for reducing pressure pulsation of an axial plunger pump comprises a plunger body, and an overflowing channel is formed in the plunger body. At least two limiting devices are sequentially arranged in the overflowing channel in the oil flowing direction, a pulsation reducing device is slidably connected between the two limiting devices, and the pulsation reducing device comprises at least two flow guiding pieces, a first elastic piece and a filtering piece; the flow guide part comprises a fixed second flow guide plate and a first flow guide plate capable of swinging along with flowing of the oil liquid, so that the flow guide part can buffer the oil liquid at different flow speeds. In the oil liquid flowing process, the pulsation reducing device moves in the oil liquid flowing direction, pulsation energy of oil liquid in the moving process is weakened by a combined structure of the filtering piece and the flow guiding piece, and after the pulsation reducing device moves to one side to abut against one limiting device, the first elastic piece continues to be stressed and deforms; and then the first elastic piece further absorbs the residual pulsation energy through the recovery effect of the compressed first elastic piece.

Description

Technical Field

[0001] The invention relates to the technical field of plunger pumps, and in particular to a plunger for reducing pressure pulsation of an axial plunger pump. Background Art

[0002] As one of the common hydraulic components in hydraulic systems, axial piston pumps are widely used in engineering machinery, aerospace, shipbuilding, metallurgy and other fields. In hydraulic systems, piston pumps are widely used due to their high efficiency. However, piston pumps often produce significant pulsation effects under high pressure and high speed conditions, affecting the stability and efficiency of the pump. Oil pulsation not only causes pressure fluctuations and unstable flow, but also causes cavitation, aggravates pump wear and shortens the service life of the equipment.

[0003] The existing technology has proposed a variety of methods to reduce pulsation and cavitation effects, including flow pulsation absorbers, active control valve technology, and multi-stage filter structure design, but these methods often have problems such as complex design and high manufacturing costs. In addition, although these methods can reduce pulsation and cavitation to a certain extent, it is often difficult to take into account the improvement of pump efficiency. Summary of the invention

[0004] In view of the shortcomings of the background technology, an object of the present invention is to provide a plunger for reducing the pressure pulsation of an axial piston pump.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A plunger for reducing pressure pulsation of an axial piston pump, characterized in that it comprises a plunger body, wherein a flow passage is arranged inside the plunger body; at least two limit devices are arranged in sequence in the flow passage, and a pulsation reducing device is slidably connected between the two limit devices in the flow passage, and a first elastic member is arranged in the pulsation reducing device;

[0007] When the oil flows, the pulsation reducing device moves along the flow direction of the oil until one side abuts against one of the limit devices. The first elastic member is deformed by the force, and the pulsation energy of the oil is balanced and dissipated by the elastic potential energy of the first elastic member after compression.

[0008] Furthermore, the pulsation reducing device also includes at least two flow guides, the two flow guides are slidably connected to the flow passage, and the first elastic member is provided between the two flow guides.

[0009] Furthermore, the pulsation reducing device also includes a plurality of filter elements, the filter elements are installed on two side surfaces of the flow guide element, and the filter elements have a plurality of filter holes arranged at equal intervals.

[0010] Furthermore, a plurality of first guide plates are provided between the two filter elements, and one end of each of the first guide plates is pivotally connected to one of the filter elements, and the other end can rotate around the pivotal position.

[0011] Furthermore, two adjacent first guide plates are pivotally connected to the filter elements on both sides, so that the rotation directions of the two adjacent first guide plates are opposite.

[0012] Furthermore, a second elastic member is connected to one end of the first guide plate away from the pivot connection, and one end of the second elastic member is connected to the first guide plate, and the other end is connected to the filter element.

[0013] Furthermore, each of the first guide plates is parallel to each other; a second guide plate is provided between two adjacent first guide plates, each of the second guide plates is parallel to each other, and the first guide plates and the second guide plates are arranged alternately.

[0014] Furthermore, the first guide plate and the second guide plate are inclined in opposite directions.

[0015] Furthermore, a liquid flow channel with openings of different sizes at both ends is formed between the adjacent first guide plates and the second guide plates, and the liquid flow channel includes first liquid flow channels and second liquid flow channels that are alternately distributed.

[0016] Furthermore, the distance between the two limit devices is equal to the total length of the pulsation reducing device; when the first elastic member does not deform, the two guide members are respectively in contact with the two limit devices.

[0017] The beneficial effects of the present invention are:

[0018] 1. The present invention proposes a plunger for reducing the pressure pulsation of an axial piston pump, wherein a flow passage is provided inside the plunger, and at least two limit devices are provided inside the flow passage, and a pulsation reducing device is slidably connected between the two limit devices, and the pulsation reducing device includes a first elastic member. During the process of absorbing or discharging liquid, the first elastic member is compressed, and the pressure fluctuation of the oil is converted into elastic potential energy through mechanical elasticity, and the pulsation energy of the oil is balanced and dissipated through its restoring force, thereby improving the performance and life of the plunger pump.

[0019] 2. The present invention proposes a plunger for reducing the pressure pulsation of an axial piston pump. The pulsation reducing device also includes at least two flow guides. The two ends of the flow guides are respectively connected with filter elements, which can filter impurities, reduce the turbulence and pressure fluctuation of the oil when passing through the inner cavity of the plunger, ensure the stability of the oil flow direction and reduce turbulence. The filter element has a plurality of filter holes arranged at equal distances, which further ensures the filtering effect and flow efficiency.

[0020] 3. The plunger for reducing the pressure pulsation of an axial piston pump proposed by the present invention has a limiter in the flow passage of the plunger to limit the movement of the flow guide and the first elastic member to the outside. The distance between the two limiters just matches the total length of the pulsation reducing device. The just matching length can prevent the pulsation reducing device from moving randomly in the flow passage inside the plunger, ensuring the stability of the pulsation reducing device during operation. It can also ensure that in the case of slight pulsation of the oil, the spring can be compressed to provide a restoring force to reduce the pulsation.

[0021] 4. The present invention proposes a plunger for reducing the pressure pulsation of an axial piston pump, wherein the guide member includes a plurality of parallel first guide plates, a second guide plate is arranged between two adjacent first guide plates, a liquid flow channel is formed between the adjacent first guide plates and the second guide plates, and the openings at both ends of each liquid flow channel are of different sizes. Such a design increases the flow rate of the oil when passing through the component, thereby suppressing the reflux of the oil itself, and at the same time improves the working efficiency of the plunger to a certain extent.

[0022] 5. The plunger for reducing the pressure pulsation of an axial piston pump proposed by the present invention has one end of a first guide plate connected to a filter element by a pivoting manner, and the other end connected to another filter element by a second elastic member. When the oil flows through the guide element, the inclination angle of the first guide plate can be adaptively adjusted following the flow rate of the oil, and the oil with different flow rates can be effectively buffered and adjusted, so that the pulsation reducing device can adapt to various working conditions, reduce cavitation, extend the service life of the equipment, and ensure that the pulsation reducing device remains stable under different working conditions. The first guide plate can automatically adjust under different liquid flow rates.

[0023] 6. The present invention proposes a plunger for reducing pressure pulsation of an axial piston pump, wherein the pivot positions of two adjacent first guide plates are opposite, and the two first guide plates are respectively connected to two filter elements, thereby ensuring uniform force on the entire guide element and improving the stability of its structure.

[0024] 7. The present invention proposes a plunger for reducing the pressure pulsation of an axial piston pump, which realizes multi-stage pulsation absorption through the combined design of a first elastic member, a filter member and a flow guide member. It has a simple structure, low manufacturing and maintenance costs, and can better adapt to actual industrial needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1A cross-sectional view of a plunger for reducing pressure pulsation of an axial piston pump according to the present invention;

[0027] Figure 2 for Figure 1 A partial enlarged view of the middle A;

[0028] Figure 3 A schematic diagram of a pulsation reducing device for reducing the pressure pulsation of an axial piston pump according to the present invention;

[0029] Figure 4 It is a schematic diagram of a flow guide member and a filter member of a plunger for reducing pressure pulsation of an axial piston pump according to the present invention;

[0030] Figure 5 for Figure 4 A partial enlarged view of point B in the middle;

[0031] Figure 6 is a schematic diagram of the plunger in the present invention when the first elastic member is in a compressed state;

[0032] Figure 7 A schematic diagram comparing the outlet pressure pulsation amplitudes of the present invention and the prior art;

[0033] In the figure, 10, plunger body; 101, flow channel; 102, through hole; 103, connecting hole; 20, limit device; 30, pulsation reducing device; 40, first elastic member; 50, guide member; 501, fixing frame; 502, second guide plate; 503, first guide plate; 504, second elastic member; 505, hinge; 60, filter element; 70, plunger head; 701, throttling hole. DETAILED DESCRIPTION

[0034] Combine the following Figure 1-7 The present invention is described in detail.

[0035] The present invention provides a plunger for reducing the pressure pulsation of an axial piston pump, such as Figure 1 and Figure 2As shown, it includes a plunger body 10, and a flow channel 101 is arranged inside the plunger body 10; at least two limit devices 20 are arranged in sequence in the flow channel 101. The flow channel 101 is slidably connected with a pulsation reduction device 30 between the two limit devices 20, and a first elastic member 40 is arranged in the pulsation reduction device 30. In this embodiment, there are two limit devices 20, which are arranged in sequence along the liquid flow direction, respectively abutting against the two ends of the pulsation reduction device 30 to limit the movement of the pulsation reduction device 30. The limit device 20 in this embodiment is a circular ring, and its outer periphery is detachably fixed to the inner wall of the flow channel 101 by a locking device. When in use, first assemble a limit device 20, fix it with a locking device, install the pulsation reduction device 30, and finally assemble the second limit device 20; when disassembling, open the outermost locking device to disassemble a limit device 20, then separate the pulsation reduction device 30 from the flow channel 101, and finally open another locking device to disassemble the inner limit device 20. When working after assembly, the oil enters the flow channel 101, and the pulsation reduction device 30 moves along the flow direction of the oil until one side abuts against one of the limit devices 20, causing the first elastic member 40 to deform, and the first elastic member 40 absorbs the pulsation energy through its recovery effect after being compressed. Furthermore, one end of the flow channel 101 is connected to a connecting hole 103, and the other end is connected to a through hole 102; the plunger includes an integrally formed plunger body 10 and a plunger head 70, and a throttling hole 701 connected to the connecting hole 103 is provided in the plunger head 70. The plunger further includes a cavity (not shown in the figure), which is arranged around the flow channel 101 .

[0036] In this embodiment, the pulsation reducing device 30 also includes a plurality of filters 60, which are connected to the two end surfaces of the guide member 50. The filter member 60 is equidistantly provided with a plurality of filter holes, which can filter impurities and absorb pulsation energy of the oil entering the flow channel 101. During operation, the oil enters the flow channel 101 of the plunger, and first passes through the guide member 50 and the filter member 60 to complete the initial filtration and absorption of pulsation energy. Then, the first elastic member 40 further absorbs the remaining pulsation energy through its recovery effect after being compressed, and converts it into the elastic potential energy of the first elastic member 40, so as to achieve the effect of reducing pulsation, thereby ensuring that the oil pulsation of the plunger under high-speed and high-pressure conditions is as small as possible, and ensuring the stability and efficiency of the entire working system. Thus, multi-stage pulsation absorption is completed. In this embodiment, the filter member 60 and the guide member 50 are integrally formed.

[0037] In this embodiment, Figure 3As shown, the pulsation reducing device 30 also includes at least two guide members 50. In this embodiment, the guide member 50 in this embodiment is an adaptive buffer truss, which includes a fixed truss and an active truss with a compartment movable design, wherein the fixed truss is composed of a second guide plate 502 and a fixed frame 501, which is used to support the filter 60; the active truss is composed of a first guide plate 503, one end of the first guide plate 503 is pivoted to the filter 60, and when the oil flows, the first guide plate 503 can rotate around the pivot point to provide buffering. The two guide members 50 are slidably connected to the flow channel 101, and the first elastic member 40 is arranged between the two guide members 50. Specifically, the guide member 50 includes a plurality of first guide plates 503 arranged between the two filter elements 60, and each first guide plate 503 is parallel to each other; a second guide plate 502 is arranged between two adjacent first guide plates 503, and each first guide plate 503 is parallel to each other. Furthermore, the second guide plate 502 and the first guide plate 503 are inclined in opposite directions. Specifically, the fixing frame 501 is adapted to the flow passage 101 to provide support for the entire guide member 50. Each guide member 50 includes two fixing frames 501, and the first guide plate 503 and the second guide plate 502 are alternately arranged between the two fixing frames 501. Figure 5 As shown, one end of the first guide plate 503 is connected to the filter 60 at one end of the guide member 50 through a foldable hinge 505, and the opposite side of the other end of the first guide plate 503 is connected to another filter 60 by installing a second elastic member 504. The second elastic member 504 is an arc spring with a specific stiffness coefficient. The design of the hinge 505 allows the movable truss to be freely folded within a certain angle range, thereby providing a good buffering effect. The guide member 50 can adjust the angle of the first guide plate 503 according to the flow velocity and working conditions, thereby adjusting the guide space in real time to ensure the stability of the flow velocity and flow rate and reduce the occurrence of turbulence and pulsation.

[0038] In this embodiment, hinges 505 and second elastic members 504 are connected to both sides of each first guide plate 503, respectively. The first guide plate 503 can produce adaptive deformation under the action of external force through the combination of the hinges 505 and the second elastic member 504, thereby achieving a buffering effect. In this embodiment, two adjacent first guide plates 503 are respectively pivoted to the filter members 60 on both sides, so that the rotation directions of the two adjacent first guide plates 503 are opposite. The positions of the hinges 505 and the second elastic member 504 of the two adjacent first guide plates 503 are opposite. Specifically, if the hinge 505 of the first first guide plate 503 is set at the left end and the second elastic member 504 is set at the right end, then the second adjacent first guide plate 503 adopts the opposite arrangement, that is, the hinge 505 is set at the right end and the second elastic member 504 is set at the left end, and so on. This alternating arrangement can ensure that the entire guide member 50 system is evenly stressed and improve the stability of the structure.

[0039] In this embodiment, a liquid flow channel with different opening sizes at both ends is formed between the second guide plate 502 and the first guide plate 503; the fixed frame 501 is tilted and a liquid flow channel is also formed between the adjacent second guide plate 502 or the first guide plate 503. When the first guide plate 503 is not subjected to force and swings, the openings at both ends of each liquid flow channel are symmetrically arranged, so that the flow rate of the oil is increased when passing through the component, thereby suppressing the reflux phenomenon of the oil itself, and at the same time improving the working efficiency of the plunger to a certain extent. In this embodiment, the liquid flow channel includes a first liquid flow channel and a second liquid flow channel that are alternately distributed. The alternating arrangement of the second guide plate 502 and the movable first guide plate 503 not only ensures the stability of the overall structure, but also provides the necessary buffering function. Among them, the end with a larger opening of the first liquid flow channel is arranged close to an opening of the flow channel 101, and the end with a larger opening of the second liquid flow channel is arranged close to another opening of the flow channel 101. Specifically, in this embodiment, the end of the first liquid flow channel with a larger opening is disposed close to the through hole 102 , and the end of the second liquid flow channel with a larger opening is disposed close to the connecting hole 103 .

[0040] In this embodiment, in actual application, the hinge 505 is designed to be made of high-strength alloy material, and its folding angle range can be controlled between 0-45 degrees, ensuring that sufficient buffer space can be provided when impacted, while not affecting the stability of the overall structure due to excessive deformation. The bearing of the hinge 505 adopts a self-lubricating bearing, which can reduce the friction resistance during movement and improve the sensitivity and service life of the system. In this embodiment, the second elastic member 504 is an arc spring, which is made of metal materials such as 65Mn steel; its arc radius is 50-80mm, the wire diameter is 3-5mm, and the number of turns is 8-12 turns. The stiffness coefficient of the second elastic member 504 can be adjusted within the range of 2-5N / mm according to the actual application scenario, which can not only ensure sufficient support strength, but also provide a moderate deformation amount when impacted. Furthermore, the surface of the second elastic member 504 is treated with anti-corrosion to improve its service life in an oil environment.

[0041] In this embodiment, Figure 4As shown, the two limit devices 20 are distributed up and down, one of which is close to the connecting hole 103, and the other limit device 20 is close to the through hole 102, so as to limit the movement of the pulsation reducing device 30. Specifically, the spacing distance between the two limit devices 20 is exactly the same as the length of the entire pulsation reducing device 30, and the pulsation reducing device 30 can be just clamped from both ends to ensure that the pulsation reducing device 30 is provided with a unilateral support force when the plunger absorbs or discharges oil, so that the first elastic member 201 can be compressed when the oil pulsates to provide appropriate absorption and restoring force, and at the same time, the exactly matching length can prevent the pulsation reducing device 30 from moving randomly in the flow channel 101 inside the plunger, and can also ensure that when the oil pulsates slightly, the first elastic member 40 can also be compressed to provide restoring force to reduce pulsation. Specifically, in this embodiment, the limit device 20 is made of 45# steel, with an inner cavity diameter of 34mm and a wall thickness of 3mm, which can provide reliable radial constraints for the first elastic member 40. At the same time, an annular step structure is provided on the inner circumference of the limiting device 20, and the step height is 4 mm, which can prevent the first elastic member 40 from axial movement during operation.

[0042] like Figure 6 As shown, the oil flows from the through hole 102 into the flow channel 101, and most of the oil enters the connecting hole 103 through the first liquid flow channel, so that the guide member 50 and the filter member 60 near the through hole 102 leave the limit device 20 and move toward another limit device 20, and the first elastic member 40 is deformed and compressed. In this process, the combination of the guide member 50 and the filter member 60 absorbs the pulsation energy of the oil, and the first elastic member 40 further absorbs the remaining pulsation energy through its recovery effect after being compressed. Specifically, the first elastic member 40 can convert the kinetic energy generated by the pulsation of the oil into elastic potential energy and store it through its recovery effect after being compressed, and release the stored energy in an appropriate manner when the oil pressure decreases, thereby forming a dynamic balance process. In this embodiment, when the system is working, the oil can enter the flow channel 101 through the through hole 102 at a working pressure of 5-40MPa.

[0043] In this embodiment, the filter element 60 is a porous fluid resonance control array, and each filter hole is a regular hexagonal structure channel arranged in a honeycomb shape. In actual production and use, the pore size and filter hole density of the filter element 60 can be optimized according to the flow rate and pressure of the oil to ensure the filtering effect and flow efficiency. Under the action of the porous fluid resonance control array, impurities in the oil can be removed and the oil can be guided to flow evenly. At the same time, due to its special structure, the porous fluid resonance control array can significantly reduce the risk of pulsation and cavitation to a certain extent, and improve the working efficiency and life of the plunger pump.

[0044] In this embodiment, when the oil passes through the pulsation reduction device 30, the oil pulsation is weakened by the combined structure of the filter 60 and the guide member 50, and then the first elastic member 40 further absorbs the remaining pulsation energy through its recovery effect after being compressed, and converts it into the elastic potential energy of the first elastic member 40, thereby achieving the effect of reducing pulsation, thereby ensuring that the oil pulsation of the plunger under high-speed and high-pressure conditions is as small as possible, and ensuring the stability and efficiency of the entire working system. For oils with different flow rates, the guide member 50 can adaptively adjust the angle of the first guide plate 503 to reduce the energy of the oil and achieve the effect of smoothing the flow rate. Specifically, when the flow rate is large, the second elastic member 504 installed on the first guide plate 503 in the guide member 50 is compressed, and the additional fluid energy is offset by the second elastic member 504 on the guide member 50, effectively slowing down the flow rate and avoiding cavitation and cavitation risks.

[0045] Specifically, according to the flow continuity equation in fluid mechanics, when the oil passes through the porous fluid resonance control array, the relationship between its velocity V and the pipe cross-sectional area A is (Formula 1):

[0046] A1V1=A2V2

[0047] Since the cross-sectional area of ​​the hexagonal channels of the porous fluid resonance control array in the present invention is small, the flow velocity V2 of the oil when passing through these filter holes increases, and the oil flow velocity at the filter hole outlet gradually tends to be stable due to the good flow guidance of the honeycomb hexagonal filter holes. By setting a reasonable area of ​​the honeycomb hexagonal filter holes, turbulence and flow instability can be further reduced, and the pulsation effect can be reduced.

[0048] Secondly, according to the Bernoulli equation (Formula 2):

[0049] P+1 / 2ρv 2 +ρgh=C

[0050] Where: P is pressure, ρ is oil density, v is flow velocity, g is gravitational acceleration, and h is height.

[0051] The arrangement of the honeycomb hexagonal filter hole structure in this embodiment allows the fluid to present a uniform flow velocity distribution when passing through the filter hole, reducing local pressure fluctuations, thereby reducing the possibility of cavitation. At the same time, the geometric structure of the hexagonal filter hole effectively reduces the local high flow velocity area, which can further reduce the cavitation phenomenon.

[0052] Secondly, the porous design of the honeycomb hexagonal structure helps to control the turbulent or laminar state of the fluid. According to the Reynolds number formula, the Reynolds number Re is a key parameter used to determine the flow state. A low Reynolds number corresponds to laminar flow, and a higher Reynolds number corresponds to turbulent flow. By setting a smaller characteristic size of the channel, the Reynolds number can be reduced, turbulence can be reduced, and the smoothness of the flow can be ensured. According to the Reynolds number formula (Formula 3):

[0053] Re=(ρvD)÷μ

[0054] Where: Re is the Reynolds number, ρ is the oil density, v is the flow velocity, D is the characteristic diameter of the pipe, and μ is the dynamic viscosity of the oil.

[0055] By controlling the flow velocity v and characteristic diameter D, the turbulent and laminar flow characteristics in the system can be optimized to ensure a more stable oil flow and further reduce pulsation.

[0056] In addition, the honeycomb hexagonal structure can reduce the pressure drop when the fluid passes through the filter holes, thereby smoothing the flow and reducing pulsation. The Darcy-Weisbach equation (Formula 4) is used for analysis as follows:

[0057] ΔP=f×(L÷D)×(ρv 2 ÷2)

[0058] Where: ΔP is the pressure drop in the flow, f is the Darcy friction coefficient, L is the flow channel length, D is the characteristic size of the hexagonal channel, ρ is the fluid density, and v is the fluid flow rate.

[0059] By relying on the hexagonal pore structure, the friction loss f can be reduced, thereby reducing the pressure drop ΔP generated during the flow process, making the flow rate of the oil more uniform, and reducing turbulence and pressure fluctuations.

[0060] Finally, the relationship between bubble radius and cavitation pressure (Formula 5) is analyzed:

[0061] P 气蚀 =(2σ)÷R

[0062] Where: P 气蚀 is the cavitation pressure, σ is the surface tension of the fluid, and R is the radius of the oil microbubble.

[0063] By speeding up the oil flow rate and evenly distributing the pressure, the hexagonal channel can effectively reduce the generation of bubbles (i.e. reduce R), thereby reducing the cavitation pressure P. 气蚀 This indicates that the hexagonal hole design helps to reduce cavitation.

[0064] In summary, by integrating the above formulas 1-5, a formula based on flow rate, filter hole characteristics, pressure change and cavitation suppression is obtained, which is expressed as (Formula 6):

[0065] P 脉动 ∝(ΔP÷v)×(Re÷D)+(2σ÷2)

[0066] The special geometric structure of the honeycomb hexagonal filter holes selected in this embodiment has good flow guidance, reasonable filter hole area, small characteristic size D, pressure drop ΔP, and Reynolds number Re, which can make the flow rate of the oil uniform, reduce turbulence, turbulence and pressure fluctuations, thereby reducing oil pulsation and cavitation.

[0067] In this embodiment, the first elastic member 40 is a spring, and both ends are connected to a filter member 60. The connection method can be a fixed connection method such as screws. According to Hooke's law (Formula 7):

[0068] F=-kx

[0069] Where: F is the restoring force generated by the spring, k is the spring constant, and x is the deformation of the spring.

[0070] The spring's stiffness coefficient (elastic coefficient) x determines the spring's ability to absorb pulsation. Therefore, in actual work, springs with different stiffness coefficients can be flexibly selected according to the working conditions, flow rate, and oil pulsation amplitude of the plunger pump to ensure that it can provide appropriate absorption and restoring force when the oil pulsates under different working conditions, thereby effectively reducing oil pulsation.

[0071] In this embodiment, the first elastic member 40 is a spring, and a spring of suitable material and performance can be flexibly selected according to actual working conditions. In this embodiment, the spring of the first elastic member 40 is made of high-strength alloy steel to ensure that the spring has sufficient life under high-frequency vibration and pulsation. Specifically, it is made of 65Mn spring steel to ensure that the spring has sufficient life under high-frequency vibration and pulsation. Its wire diameter is 2.5mm, the outer diameter of the spring is 32mm, the free height is 85mm, and it has 8 effective turns. Under working conditions where the oil pulsation frequency is 20-50Hz, the spring can be compressed and deformed by 12-15mm, generating a large restoring force.

[0072] When the oil pulsates, the deformation of the spring of the first elastic member 40 is directly related to the amplitude of the pulsation: the more violent the oil pulsation, the greater the deformation of the spring, and the greater the restoring force generated to weaken the oil pulsation. As a result, the spring converts the energy of the oil pulsation into elastic potential energy and ultimately weakens the impact of the pulsation on the entire system through its restoring force.

[0073] In addition, the damping effect provided by the spring can be expressed by the damping force formula (Equation 8):

[0074] F d =-cv

[0075] Among them: F d is the damping force, c is the damping coefficient, and v is the oil flow velocity.

[0076] Damping force F dAs the flow velocity v increases, the damping force F generated by the spring is compressed. d The larger it becomes, the better it absorbs the pulsation energy, making the oil flow more stable and reducing the impact of pulsation on the system. Therefore, by adjusting the elastic coefficient K and damping coefficient c of the spring, the present invention can achieve the best pulsation suppression effect under different working conditions and ensure the stability and efficient operation of the system.

[0077] By integrating the above formulas 1, 7 and 8, a correlation formula (Formula 9) between the oil pulsation of the system and the spring of the first elastic member 40 can be obtained:

[0078] F 总 ∝(kx+cv2)

[0079] Among them: F 总 It is the total force under the combined action of the damping force and the restoring force of the spring, kx is the effect of the restoring force of the spring changing with pulsation, and cv2 is the effect of the damping force increasing with the flow velocity.

[0080] The total force generated by the spring depends on the damping force and restoring force of the spring, wherein the damping force increases with the increase of flow velocity, and the restoring force increases with the increase of pulsation, so that the spring can generate a larger total force to suppress the oil pulsation under the condition of high-speed operation of the plunger or when the internal oil pulsation is large. The first elastic member 40 absorbs the energy of the oil pulsation through these two action mechanisms, thereby reducing the impact of the pulsation on the system and achieving effective suppression of the pulsation.

[0081] To sum up, in this embodiment, through the cooperation of the first elastic member 40, the guide member 50 and the filter member 60, the oil can achieve the effects of impurity filtering, pulsation reduction, cavitation reduction and flow rate acceleration after passing through the pulsation reduction device 30, thereby significantly improving the performance and life of the plunger pump, reducing cavitation and wear, improving the stability and accuracy of the system, and improving the efficiency of the system.

[0082] Specifically, the plunger and the flow distribution mechanism work together in the plunger pump to realize the pump's oil suction and oil pressure functions through the reciprocating motion of the plunger and the oil control of the flow distribution mechanism. The pressure pulsation of the axial piston pump refers to the phenomenon that the outlet pressure of the pump fluctuates periodically due to the reciprocating motion of the piston and the periodic switching of the flow distribution mechanism during the operation of the pump. The pressure pulsation rate is usually used to measure the pressure pulsation, and its expression is as follows (Formula 10):

[0083] δ=(p max -p min )÷p avg ×100%

[0084] Among them, p maxis the maximum pressure, p min is the minimum pressure, p avg is the average pressure.

[0085] from Figure 7 It can be seen that as the outlet pressure increases, the pressure fluctuation rate also increases. This is because when the outlet pressure increases, the load in the hydraulic system increases, and the reaction force on the plunger when compressing the liquid also increases, resulting in slight fluctuations in the speed and flow of the plunger movement. At the same time, factors such as leakage in the pump, valve response lag, and the compressibility of the liquid are more obvious under high pressure conditions, making the instantaneous flow unstable, which in turn causes an increase in the pressure fluctuation rate. In addition, mechanical vibrations and structural deformations will further amplify pressure fluctuations under high pressure. Compared with the plungers in the prior art, the plunger provided by the present invention can significantly reduce the outlet pressure pulsation rate of the axial piston pump, and has a good pressure pulsation suppression effect.

[0086] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A plunger for reducing pressure pulsation of an axial piston pump, characterized in that: It comprises a plunger body, wherein a flow passage is arranged inside the plunger body; at least two limit devices are arranged in sequence in the flow passage, and a pulsation reducing device is slidably connected between the two limit devices in the flow passage, and a first elastic member is arranged in the pulsation reducing device; When the oil flows, the pulsation reducing device moves along the flow direction of the oil until one side abuts against one of the limit devices. The first elastic member is deformed by the force, and the pulsation energy of the oil is balanced and dissipated by the elastic potential energy of the first elastic member after compression.

2. A plunger for reducing pressure pulsation of an axial piston pump as claimed in claim 1, characterized in that: The pulsation reducing device further includes at least two flow guides, the two flow guides are slidably connected to the flow passage, and the first elastic member is arranged between the two flow guides.

3. A plunger for reducing pressure pulsation of an axial piston pump as claimed in claim 2, characterized in that: The pulsation reducing device further comprises a plurality of filter elements, wherein the filter elements are mounted on two side surfaces of the flow guide element, and the filter elements are provided with a plurality of filter holes arranged at equal intervals.

4. A plunger for reducing pressure pulsation of an axial piston pump as claimed in claim 3, characterized in that: A plurality of first guide plates are also arranged between the two filter elements. One end of each of the first guide plates is pivotally connected to one of the filter elements, and the other end can rotate around the pivotal position.

5. A plunger for reducing pressure pulsation of an axial piston pump as claimed in claim 4, characterized in that: Two adjacent first flow guide plates are pivotally connected to the filter elements on both sides, so that the rotation directions of the two adjacent first flow guide plates are opposite.

6. A plunger for reducing pressure pulsation of an axial piston pump as claimed in claim 5, characterized in that: The end of the first guide plate away from the pivot connection is also connected to a second elastic member, one end of the second elastic member is connected to the first guide plate, and the other end is connected to the filter element.

7. A plunger for reducing pressure pulsation of an axial piston pump as claimed in claim 8, characterized in that: The first guide plates are parallel to each other; a second guide plate is arranged between two adjacent first guide plates, the second guide plates are parallel to each other, and the first guide plates and the second guide plates are arranged alternately.

8. A plunger for reducing pressure pulsation of an axial piston pump as claimed in claim 7, characterized in that: The first guide plate and the second guide plate are inclined in opposite directions.

9. A plunger for reducing pressure pulsation of an axial piston pump as claimed in claim 8, characterized in that: A liquid flow channel with openings of different sizes at both ends is formed between the adjacent first guide plates and the second guide plates, and the liquid flow channel includes first liquid flow channels and second liquid flow channels that are alternately distributed.

10. A plunger for reducing pressure pulsation of an axial piston pump as claimed in claim 9, characterized in that: The distance between the two limit devices is equal to the total length of the pulsation reducing device; when the first elastic member does not deform, the two flow guide members are respectively in contact with the two limit devices.

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