A plunger for reducing pressure pulsations in an axial piston pump

Abstract

A kind of plunger for reducing the pressure pulsation of axial plunger pump, including plunger body, plunger body is provided with flow passage inside;At least two limit devices are sequentially provided in flow passage along the direction of oil flow, and the sliding connection between two limit devices has pulsation reduction device, and pulsation reduction device includes at least two flow guides, first elastic member and filter;Flow guide includes fixed second flow guide plate, and first flow guide plate that can swing along with oil flow, so that flow guide can buffer oil of different flow rates.In the process of oil flow, pulsation reduction device moves along the direction of oil flow, and the pulsation energy of oil is weakened in the process of moving by the combined structure of filter and flow guide, when pulsation reduction device moves to one side and abuts on one of limit devices, first elastic member continues to be stressed and deforms, and then first elastic member further absorbs the remaining pulsation energy by the recovery effect of its compression.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of plunger pump, and particularly relates to a plunger for reducing pressure pulsation of an axial plunger pump. BACKGROUND

[0002] As one of common hydraulic elements in hydraulic systems, axial plunger pumps are widely used in engineering machinery, aerospace, ships, metallurgy and other fields. In hydraulic systems, plunger pumps are widely used due to their high efficiency. However, the plunger pump often produces significant pulsation effect under high pressure and high speed working conditions, which affects the stability and efficiency of the pump. Oil pulsation not only causes pressure fluctuation and flow instability, but also causes cavitation, aggravates pump wear and shortens the service life of the equipment.

[0003] The prior art has proposed various methods for reducing pulsation and cavitation effect, including flow pulsation absorber, active control valve technology and multi-stage filter structure design, but these methods often have the problems of complex design and high manufacturing cost. In addition, although these methods can reduce pulsation and cavitation to some extent, it is difficult to improve the efficiency of the pump at the same time. SUMMARY

[0004] In view of the deficiencies in the background art, the purpose of the present application is to provide a plunger for reducing pressure pulsation of an axial plunger pump.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical scheme:

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

[0007] When the oil flows, the pulsation reduction device moves along the direction of oil flow, abuts against one of the limiting devices on one side, the first elastic member is deformed under stress, and the elastic potential energy after compression of the first elastic member is used to balance and dissipate the pulsation energy of the oil.

[0008] Further, the pulsation reduction device further comprises 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.

[0009] Further, the pulsation reduction device further comprises a plurality of filter members, the filter members are installed on the two side surfaces of the flow guide, and the filter members are arranged with a plurality of filter holes at equal intervals.

[0010] Further, a plurality of first flow guides are arranged between the two filter members, one end of each of the first flow guides is pivotally connected to one of the filter members, and the other end thereof is rotatable about the pivotal connection.

[0011] Further, two adjacent first flow guides are pivotally connected to the filter members on both sides, and the two adjacent first flow guides rotate in opposite directions.

[0012] Further, the end of the first flow guide away from the pivotal connection is further connected to a second elastic member, one end of the second elastic member is connected to the first flow guide, and the other end thereof is connected to the filter member.

[0013] Further, the first flow guides are parallel to each other, a second flow guide is arranged between two adjacent first flow guides, the second flow guides are parallel to each other, and the first flow guides and the second flow guides are alternately arranged.

[0014] Further, the first flow guides and the second flow guides are inclined in opposite directions.

[0015] Further, the first flow guides and the second flow guides are inclined in opposite directions.

[0016] Further, the distance between the two limiting devices is equal to the total length of the pulsation reduction device, and when the first elastic member is not deformed, the two flow guides abut against the two limiting devices, respectively.

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

[0018] 1. The present application provides a plunger for reducing pressure pulsation of an axial plunger pump, the plunger is internally provided with a flow passage, at least two limiting devices are further arranged in the flow passage, a pulsation reduction device is slidably connected between the two limiting devices, and the pulsation reduction device comprises a first elastic member. During the liquid suction or discharge process, the first elastic member is compressed, the pressure fluctuation of the oil is converted into elastic potential energy through mechanical elasticity, and the restoring force thereof is used to balance and dissipate the pulsation energy of the oil, thereby improving the performance and service life of the plunger pump.

[0019] 2. The present application provides a plunger for reducing pressure pulsation of an axial plunger pump, the pulsation reduction device further comprises at least two flow guides, and filter members are connected to both ends of the flow guides, which can filter impurities, reduce the turbulent flow and pressure fluctuation of the oil when passing through the inner cavity of the plunger, ensure the stability of the flow direction of the oil and reduce the turbulence. The filter members are provided with a plurality of filter holes arranged at equal intervals, which further ensure the filtering effect and flow efficiency.

[0020] 3. The plunger for reducing pressure pulsation of an axial plunger pump, wherein the flow passage of the plunger is further provided with limiting devices for limiting the movement of the flow guide and the first elastic member to the outside, and the distance between the two limiting devices is just the same as the total length of the pulsation reduction device, so that the pulsation reduction device is prevented from moving randomly in the flow passage of the plunger, and the stability of the pulsation reduction device in operation is ensured, and the spring can also be compressed to provide restoring force for reducing pulsation under the condition of slight pulsation of oil.

[0021] 4. The plunger for reducing pressure pulsation of an axial plunger pump, wherein the flow guide comprises a plurality of parallel first flow guide plates, and a second flow guide plate is arranged between adjacent two first flow guide plates, and a liquid flow passage is formed between adjacent first flow guide plates and second flow guide plates, and the opening sizes of the two ends of each liquid flow passage are different, so that the flow rate of oil is increased when the oil passes through the component, and the backflow of oil is inhibited, and the working efficiency of the plunger is improved to a certain extent.

[0022] 5. The plunger for reducing pressure pulsation of an axial plunger pump, wherein one end of the first flow guide plate is connected with a filter through pivoting, and the other end is connected with another filter through a second elastic member, and the inclination angle of the first flow guide plate can be adaptively adjusted according to the flow rate of oil when the oil flows through the flow guide, so that the pulsation reduction device can adapt to various working conditions, the cavitation phenomenon is reduced, the service life of the equipment is prolonged, and the stability of the pulsation reduction device under different working conditions is ensured, and the first flow guide plate can be automatically adjusted under different liquid flow rates.

[0023] 6. The plunger for reducing pressure pulsation of an axial plunger pump, wherein the pivoting positions of the two adjacent first flow guide plates are opposite, and the two first flow guide plates are connected with two filters respectively, so that the stress of the entire flow guide is uniform, and the stability of the structure is improved.

[0024] 7. The plunger for reducing pressure pulsation of an axial plunger pump, wherein the combination of the first elastic member, the filter and the flow guide realizes multi-stage pulsation absorption, and the structure is simple, and the manufacturing and maintenance costs are low, so that the actual industrial demand can be better adapted. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor.

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

[0027] Figure 2 A sectional view of a plunger for reducing pressure pulsation of an axial plunger pump according to the present application; Figure 1 A partial enlarged view of A in the figure;

[0028] Figure 3 A schematic view of a pulsation reducing device of a plunger for reducing pressure pulsation of an axial plunger pump according to the present application;

[0029] Figure 4 A schematic view of a flow guide and a filter of a plunger for reducing pressure pulsation of an axial plunger pump according to the present application;

[0030] Figure 5 A sectional view of a plunger for reducing pressure pulsation of an axial plunger pump according to the present application; Figure 4 A partial enlarged view of B in the figure;

[0031] Figure 6 A schematic view of a plunger with a first elastic member in a compressed state according to the present application;

[0032] Figure 7 A schematic view of a comparison of outlet pressure pulsation amplitude according to the present application and prior art;

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

[0034] The present application will be described in detail below. Figures 1-7 The present application will be described in detail below.

[0035] The present application provides a plunger for reducing pressure pulsation of an axial plunger pump, as shown in Figure 1 and Figure 2As shown, the plunger includes a plunger body 10, the plunger body 10 is internally provided with a flow passage 101; the flow passage 101 is sequentially provided with at least two limiting devices 20. The flow passage 101 is slidably connected with a pulsation reduction device 30 between the two limiting devices 20, and the pulsation reduction device 30 is internally provided with a first elastic member 40. In this embodiment, the limiting device 20 is two, which are sequentially arranged along the liquid flow direction, and abut against both ends of the pulsation reduction device 30 respectively to limit the movement of the pulsation reduction device 30. The limiting device 20 in this embodiment is a circular ring, and the outer periphery thereof is detachably fixed on the inner wall of the flow passage 101 through a locking device. In use, one limiting device 20 is assembled first, and then the pulsation reduction device 30 is assembled after the limiting device 20 is fixed through the locking device; when disassembling, the outermost locking device is opened to disassemble one limiting device 20, and then the pulsation reduction device 30 is separated from the flow passage 101, and finally the other locking device is opened to disassemble the inner limiting device 20. After assembly, when working, the oil enters the flow passage 101, and the pulsation reduction device 30 moves along the oil flow direction until abutting against one of the limiting devices 20, so that the first elastic member 40 is deformed, and the first elastic member 40 absorbs the pulsation energy through the recovery effect after being compressed. Further, one end of the flow passage 101 is communicated with a connecting hole 103, and the other end is communicated with a through hole 102; the plunger includes an integrally formed plunger body 10 and a plunger head 70, and the plunger head 70 is internally provided with a throttling hole 701 communicated with the connecting hole 103. The plunger further includes a cavity (not marked in the figure) which is arranged around the flow passage 101.

[0036] In this embodiment, the pulsation reduction device 30 further includes a plurality of filter members 60, the filter members 60 are connected to the two end faces of the flow guide member 50, and the filter members 60 are equidistantly provided with a plurality of filter holes, which can filter impurities and absorb pulsation energy of the oil entering the flow passage 101. In work, the oil enters the flow passage 101 of the plunger, first passes through the flow guide member 50 and the filter member 60 to complete the first filtration and absorption of the pulsation energy, and then the first elastic member 40 further absorbs the remaining pulsation energy through the recovery effect after being compressed, and converts it into the elastic potential energy of the first elastic member 40 to achieve the effect of reducing the pulsation, thereby ensuring that the oil pulsation of the plunger under high-speed and high-pressure working 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 is integrally formed with the flow guide member 50.

[0037] In this embodiment, as shown in Figure 3As shown, the pulsation reduction device 30 further comprises at least two flow guides 50. In this embodiment, the flow guides 50 are adaptive buffering trusses, which comprise fixed trusses and movable trusses designed to be movable. The fixed trusses are composed of second flow guides 502 and fixed frames 501, which are used to support the filter members 60. The movable trusses are composed of first flow guides 503, one end of which is pivotally connected to the filter members 60. When the oil flows, the first flow guides 503 can rotate around the pivot connection to provide buffering. The two flow guides 50 are slidingly connected to the flow passage 101, and the first elastic members 40 are arranged between the two flow guides 50. Specifically, the flow guides 50 comprise a plurality of first flow guides 503 arranged between the two filter members 60, and each first flow guide 503 is parallel to each other. A second flow guide 502 is arranged between adjacent two first flow guides 503, and each first flow guide 503 is parallel to each other. Moreover, the inclination directions of the second flow guides 502 and the first flow guides 503 are opposite. Specifically, the fixed frames 501 are adapted to the flow passage 101 to provide support for the entire flow guide 50. Each flow guide 50 comprises two fixed frames 501, and the first flow guides 503 and the second flow guides 502 are alternately arranged between the two fixed frames 501. As shown in the figure, Figure 5 As shown, one end of the first flow guide 503 is connected to the filter member 60 at one end of the flow guide 50 through a foldable hinge 505, and the opposite side of the other end of the first flow guide 503 is connected to the other filter member 60 through the installation of a second elastic member 504. The second elastic member 504 is an arc-shaped 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 good buffering effect. The flow guide 50 can adjust the angle of the first flow guide 503 according to the flow rate and working conditions, so as to adjust the flow guide space in real time to ensure the stability of the flow rate and flow, and reduce the occurrence of turbulence and pulsation.

[0038] In this embodiment, the two sides of each first flow guide 503 are respectively connected with the hinge 505 and the second elastic member 504. The first flow guide 503 can produce adaptive deformation under external force through the combination of the hinge 505 and the second elastic member 504, thereby realizing the buffering effect. Moreover, in this embodiment, the adjacent two first flow guides 503 are respectively pivotally connected to the filter members 60 on both sides, so that the rotation directions of the adjacent two first flow guides 503 are opposite. The positions of the hinge 505 and the second elastic member 504 of the adjacent two first flow guides 503 are opposite. Specifically, if the hinge 505 of the first first flow guide 503 is arranged at the left end and the second elastic member 504 is arranged at the right end, the adjacent second first flow guide 503 is arranged in the opposite way, i.e. the hinge 505 is arranged at the right end and the second elastic member 504 is arranged at the left end, and so on. This alternative arrangement can ensure that the entire flow guide 50 system is uniformly stressed, thereby improving the stability of the structure.

[0039] In the embodiment, the second flow guide plate 502 and the first flow guide plate 503 form liquid flow channels with different sizes of openings at both ends; the fixed frame 501 is inclined and arranged, and liquid flow channels are also formed between the adjacent second flow guide plate 502 or the first flow guide plate 503. When the first flow guide plate 503 is not forced to swing and change, the two ends of each liquid flow channel are symmetrically arranged, so that the flow rate of the oil liquid passing through the component is improved, thereby inhibiting the backflow phenomenon of the oil liquid itself, and at the same time, the working efficiency of the plunger is improved to a certain extent. In the embodiment, the liquid flow channel includes first liquid flow channels and second liquid flow channels which are alternately distributed. The alternate arrangement of the second flow guide plate 502 and the movable first flow guide plate 503 not only ensures the stability of the overall structure, but also provides the necessary buffering function. Among them, the larger end of the first liquid flow channel is arranged close to one opening of the flow passage 101, and the larger end of the second liquid flow channel is arranged close to the other opening of the flow passage 101. Specifically, in the embodiment, the larger end of the first liquid flow channel is arranged close to the through hole 102, and the larger end of the second liquid flow channel is arranged close to the connecting hole 103.

[0040] In actual application, the hinge 505 in the embodiment is made of high-strength alloy material, and the folding angle range can be controlled between 0-45 degrees, which can provide sufficient buffer space when impacted, and at the same time, the stability of the overall structure will not be affected 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. The second elastic member 504 in the embodiment is an arc spring made of metal material such as 65Mn steel; the radius of curvature 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 in the range of 2-5N / mm according to the actual application scene, which can not only ensure sufficient supporting strength, but also provide a moderate deformation amount when impacted. Further, the surface of the second elastic member 504 is treated to improve its service life in the oil environment.

[0041] In the embodiment, as shown in FIG. 6, the second flow guide plate 502 and the first flow guide plate 503 are arranged alternately, and the fixed frame 501 is arranged between the second flow guide plate 502 and the first flow guide plate 503. Figure 4As shown, the two limit devices 20 are arranged in an up-down manner, one of which is close to the connecting hole 103, and the other is close to the through hole 102, so as to limit the movement of the reducing pulsation device 30. Specifically, the interval distance between the two limit devices 20 is just the same as the length of the whole reducing pulsation device 30, which can just clamp the reducing pulsation device 30 from both ends, so as to provide unilateral support force for the reducing pulsation device 30 in the case of oil suction or discharge of the plunger, so that the first elastic member 201 can be compressed when the oil pulsates to provide appropriate absorption and recovery force, and the just fitting length can prevent the reducing pulsation device 30 from moving in the internal flow channel 101 of the plunger, and also ensure that the first elastic member 40 can be compressed to provide recovery force to reduce pulsation in the case of slight oil pulsation. Specifically, in the embodiment, the limit device 20 is made of 45 steel, the inner diameter of which is 34 mm, and the wall thickness is 3 mm, which can provide reliable radial constraint for the first elastic member 40. At the same time, the inner periphery of the limit device 20 is provided with an annular stepped structure, and the step height is 4 mm, which can prevent the first elastic member 40 from moving axially during work.

[0042] As shown, Figure 6 In the process, the flow guide 50 and the filter 60 combinedly absorb the pulsation energy of the oil, and the first elastic member 40 further absorbs the remaining pulsation energy through the recovery effect after being compressed. Specifically, the first elastic member 40 can convert the kinetic energy generated by the oil pulsation into elastic potential energy and store it, and then release the stored energy in an appropriate way when the oil pressure decreases, so as to form a dynamic balance process. In the embodiment, when the system works, the oil can enter the flow channel 101 through the through hole 102 at a working pressure of 5-40 MPa.

[0043] In the embodiment, the filter 60 is a porous fluid resonance control array, and each filter hole is a regular hexagonal structure hole arranged in a honeycomb shape. In actual production and use, the size and density of the filter holes of the filter 60 can be optimized and designed according to the flow rate and pressure of the oil, so as 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 uniformly guided to flow. At the same time, due to its special structure, the porous fluid resonance control array can significantly reduce the pulsation and cavitation risk to a certain extent, and improve the working efficiency and service 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 flow guide 50, and then the first elastic member 40 further absorbs the remaining pulsation energy through the recovery effect of its compression and converts it into the elastic potential energy of the first elastic member 40, achieving the effect of reducing pulsation, thereby ensuring that the oil pulsation of the plunger under high-speed and high-pressure working conditions is as small as possible, and ensuring the stability and efficiency of the entire working system. For oil of different flow rates, the flow guide 50 can adaptively adjust the angle of the first flow 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 flow guide plate 503 in the flow guide 50 is compressed, and the additional fluid energy is offset by the second elastic member 504 on the flow guide 50, effectively slowing down the flow rate and avoiding cavitation and cavitation risks.

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

[0046] A1V1=A2V2

[0047] Because the cross-sectional area of the hexagonal hole of the porous fluid resonance regulation array in the present application is small, the flow rate V2 of the oil increases when it passes through these filter holes, and the flow rate of the oil at the outlet of the filter hole gradually tends to be stable due to the good flow guiding property of the honeycomb-shaped hexagonal filter hole. By setting a reasonable area of the honeycomb-shaped hexagonal filter hole, turbulence and flow instability can be further reduced, and the pulsation effect can be reduced.

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

[0049] P+1 / 2ρv 2 +ρgh=C

[0050] Where: P is the pressure, p is the density of the oil, v is the flow rate, g is the acceleration of gravity, and h is the height.

[0051] The arrangement of the honeycomb-shaped hexagonal filter hole structure in this embodiment causes the fluid to have a uniform flow rate distribution when passing through the filter hole, reducing local pressure fluctuations and thus reducing the likelihood of cavitation. At the same time, the geometric structure of the hexagonal filter hole effectively reduces the local high-flow-rate area, further reducing the cavitation phenomenon.

[0052] Secondly, the porous design of the honeycomb-shaped 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 for determining the flow state, with low Reynolds number corresponding to laminar flow and higher Reynolds number corresponding to turbulent flow. By setting a smaller characteristic size of the channel, the Reynolds number can be reduced, the turbulence can be reduced, and the stability of the flow can be ensured. According to the Reynolds number formula (Formula 3):

[0053] Re = (p v D) ÷ m

[0054] Where Re is the Reynolds number, p is the oil density, v is the flow rate, D is the pipe characteristic diameter, and m is the oil dynamic viscosity.

[0055] By controlling the flow rate v and the characteristic diameter D, the turbulent and laminar characteristics in the system can be optimized, ensuring more stable oil flow and further reducing pulsation.

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

[0057] AP = f x (L ÷ D) x (p v 2 ÷ 2)

[0058] Where AP is the pressure drop in the flow, f is the Darcy friction factor, L is the flow path length, D is the characteristic size of the hexagonal hole, p is the fluid density, and v is the fluid flow rate.

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

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

[0061] P 气蚀 = (2 s) ÷ R

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

[0063] By increasing the oil flow rate and uniformly distributing the pressure, the hexagonal hole 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 the cavitation phenomenon.

[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, expressed as (Formula 6):

[0065] P 脉动 a (AP ÷ v) x (Re ÷ D) + (2 s ÷ 2)

[0066] The honeycomb hexagonal filter pores selected in this embodiment have a special geometric structure with good flow guidance, reasonable pore area, small characteristic size D, pressure drop ΔP, and Reynolds number Re. This can homogenize the flow rate of the oil, reduce turbulence, turbulence and pressure fluctuations, thereby reducing oil pulsation and cavitation.

[0067] In this embodiment, the first elastic element 40 is a spring, with both ends connected to a filter element 60. The connection method can be a fixed connection such as screws. According to Hooke's Law (Equation 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 stiffness coefficient (elastic coefficient) x of a spring determines its ability to absorb pulsation. Therefore, in practical 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 they can provide appropriate absorption and restoring force when oil pulsation occurs under different working conditions, thereby effectively reducing oil pulsation.

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

[0072] When the oil pulsates, the deformation of the spring of the first elastic element 40 is directly related to the amplitude of the pulsation: the more intense the oil pulsation, the greater the deformation of the spring, and the greater the restoring force generated to weaken the oil pulsation. Thus, 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] Furthermore, the damping effect provided by the spring can be expressed by the damping force formula (Formula 8):

[0074] F d =-cv

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

[0076] Damping force F dThe pressure increases with increasing flow velocity v. When the plunger is operating at high speed, the greater the flow velocity v, the more intense the oil pulsation, and the greater the damping force F generated by the compression of the spring. d This makes the spring larger, allowing it to better absorb pulsation energy, resulting in smoother oil flow and reduced impact of pulsation on the system. Therefore, by adjusting the spring constant K and damping constant c, this invention can achieve optimal pulsation suppression under different operating conditions, ensuring system stability and efficient operation.

[0077] Integrating the above three formulas 1, 7, and 8, we can obtain the relevant formula (Formula 9) between the oil pulsation of the system and the spring of the first elastic element 40:

[0078] F 总 ∝(kx+cv2)

[0079] Wherein: F 总 It is the total force under the combined action of the spring's damping force and restoring force, kx is the effect of the spring's restoring force changing with the 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 the restoring force of the spring. The damping force increases with the increase of flow velocity, and the restoring force increases with the increase of pulsation. This allows the spring to generate a large total force to suppress oil pulsation when the plunger is running at high speed or when there is a large internal oil pulsation. The first elastic element 40 absorbs the energy of oil pulsation through these two mechanisms, thereby reducing the impact of pulsation on the system and achieving effective suppression of pulsation.

[0081] In summary, this embodiment, through the cooperation of the first elastic element 40, the flow guide 50, and the filter element 60, enables the oil to achieve the effects of impurity filtration, pulsation reduction, cavitation reduction, and flow rate acceleration after passing through the pulsation reduction device 30. This significantly improves the performance and lifespan of the plunger pump, reduces cavitation and wear, improves the stability and accuracy of the system, and increases the efficiency of the system.

[0082] Specifically, the plunger and the distribution mechanism work together in the plunger pump, achieving the pump's suction and pressure functions through the reciprocating motion of the plunger and the hydraulic control of the distribution mechanism. Pressure pulsation in an axial plunger pump refers to the periodic fluctuations in the pump's outlet pressure caused by the reciprocating motion of the piston and the periodic switching of the distribution mechanism during operation. Pressure pulsation is typically measured using the pressure pulsation rate, expressed as follows (Formula 10):

[0083] δ=(p max -p min )÷p avg ×100%

[0084] Where, p maxFor maximum pressure, p min For minimum pressure, p avg This represents the average pressure.

[0085] from Figure 7 As can be seen, the pressure fluctuation rate increases with increasing outlet pressure. This is because when the outlet pressure rises, the load on the hydraulic system increases, and the reaction force on the plunger when compressing the fluid also increases, leading to slight fluctuations in the plunger's speed and flow rate. Simultaneously, factors such as pump leakage, valve response lag, and fluid compressibility become more pronounced under high pressure conditions, resulting in unstable instantaneous flow and further increasing the pressure fluctuation rate. Furthermore, mechanical vibration and structural deformation under high pressure also amplify pressure fluctuations. Compared to existing plungers, the plunger provided by this invention can significantly reduce the outlet pressure pulsation rate of axial plunger pumps, exhibiting excellent pressure pulsation suppression effects.

[0086] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand and implement the present invention. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A plunger for reducing pressure pulsation in an axial plunger pump, characterized in that, The device includes a plunger body, which has an internal flow channel; at least two limiting devices are sequentially provided in the flow channel, and a pulsation reduction device is slidably connected between the two limiting devices, with a first elastic element provided in the pulsation reduction device. When the oil flows, the pulsation reduction device moves along the oil flow direction until it abuts against one of the limiting devices on one side. The first elastic element deforms under force and balances and dissipates the pulsation energy of the oil through the elastic potential energy of the first elastic element after compression. The pulsation reduction device further includes at least two flow guides, which are slidably connected to the flow channel, and the first elastic element is provided between the two flow guides. The pulsation reduction device also includes a plurality of filter elements, which are installed on both sides of the flow guides. The filter elements have a plurality of filter holes arranged at equal intervals. A plurality of first flow guide plates are also provided between the two filter elements. One end of each first flow guide plate is pivotally connected to a filter element, and the other end can rotate around the pivot point. Adjacent first flow guide plates are pivotally connected to the filter elements on both sides, so that the rotation directions of adjacent first flow guide plates are opposite.

2. The plunger for reducing pressure pulsation in an axial plunger pump as described in claim 1, characterized in that, The end of the first guide plate away from the pivot is also connected to a second elastic element, one end of which is connected to the first guide plate and the other end of which is connected to the filter element.

3. A plunger for reducing pressure pulsation in an axial plunger pump as described in claim 2, characterized in that, Each of the first guide vanes is parallel to each other; a second guide vane is provided between two adjacent first guide vanes, and each of the second guide vanes is parallel to each other, with the first guide vanes and the second guide vanes arranged alternately.

4. A plunger for reducing pressure pulsation in an axial plunger pump as described in claim 3, characterized in that, The first guide plate and the second guide plate are tilted in opposite directions.

5. A plunger for reducing pressure pulsation in an axial plunger pump as described in claim 4, characterized in that, The adjacent first guide plate and second guide plate form liquid flow channels with different opening sizes at both ends, and the liquid flow channels include alternating first liquid flow channels and second liquid flow channels.

6. A plunger for reducing pressure pulsation in an axial plunger pump as described in claim 5, characterized in that, The distance between the two limiting devices is equal to the total length of the pulsation reduction device; when the first elastic element does not deform, the two guide elements respectively abut against the two limiting devices.

Images