A multi-stage regulated pulsation-reducing plunger

Abstract

A kind of multistage regulation type plunger of reducing pulsation, including plunger body, plunger body is provided with overflow passage inside;At least two limiting devices are provided in the overflow passage in the oil flow direction in turn, at least two elastic plates are slidably connected in the overflow passage between two limiting devices, elastic device is provided between two elastic plates, elastic device is provided with at least two elastic members in turn from outside to inside nested.Emergency drainage process, oil pressure pulsation makes the surface of elastic plate be subjected to pressure intensity, so that elastic plate and the elastic device are deformed, in the first pulsation stage, the elastic plate deformation reduces pulsation, the elastic device is not compressed;In the second pulsation stage, one of the elastic members of the elastic device is compressed;In the third pulsation stage, two the elastic members of the elastic device are compressed simultaneously.

Description

Technical Field

[0001] This invention relates to the field of plunger pump hydraulic pressure control technology, and in particular to a multi-stage adjustable plunger for reducing pulsation. Background Technology

[0002] Piston pumps are the core of many hydraulic systems. Their main function is to draw in and pressurize oil by changing the volume of the sealed working chamber through the reciprocating motion of the piston within the cylinder, thus facilitating the use of subsequent hydraulic and pneumatic devices. The basic principle is that as the spindle rotates, the internal space of the piston chamber increases, drawing in low-pressure oil and decreasing the space, discharging high-pressure oil. Therefore, the changes in oil pressure and flow rate inside the piston are very significant. Oil pressure pulsation refers to a non-uniform pressure acting on the object being acted upon, concentrated in one area and dispersed in another. This pressure is short-lived and may exhibit a certain periodicity. It can easily lead to increased noise and vibration in the piston pump, reduced efficiency, and even serious consequences such as damage to the internal structure and oil leakage.

[0003] The existing method for reducing oil pressure pulsation is to install a pulsation damper inside the plunger pump, which is a flexible and effective approach when the plunger pump piping layout is limited. However, with the development of electronic intelligent technology, the structure of pulsation dampers has become increasingly complex and bulky, the circuit parameters are difficult to adjust, and the manufacturing cost and difficulty have increased. The small internal space of the plunger and the large number of plungers have also hindered the widespread adoption and application of pulsation dampers in the field of plunger pumps. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a multi-level adjustable plunger to reduce pulsation.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A multi-stage adjustable pulsation-reducing plunger includes a plunger body, the plunger body having an internal flow channel; at least two limiting devices are sequentially arranged in the flow channel along the oil flow direction, at least two elastic plates are slidably connected between the two limiting devices, an elastic device is arranged between the two elastic plates, and at least two elastic elements are nested in the elastic device from the outside to the inside.

[0007] During the drainage process, the oil pressure pulsation causes pressure on the surface of the elastic plate, thereby deforming the elastic plate and the elastic device. In the first pulsation stage, the deformation of the elastic plate decreases and the elastic device is not compressed. In the second pulsation stage, one of the elastic elements of the elastic device is compressed. In the third pulsation stage, both elastic elements of the elastic device are compressed simultaneously.

[0008] Furthermore, the outer surfaces of the two elastic plates are equidistantly arranged with a number of filter holes.

[0009] Furthermore, the elastic device is provided with a first elastic element and a second elastic element nested from the outside in. The elastic coefficient of the first elastic element is less than that of the second elastic element. The length and radius of the first elastic element and the length and radius of the second elastic element are also specified.

[0010] Furthermore, a mounting hole is provided at the middle position of the two elastic plates, and a fastener is provided in the mounting hole, and the second elastic element is sleeved on the fastener.

[0011] Furthermore, the second elastic member is interference-fitted with the fastener, the fastener is provided with barbs, and the two ends of the second elastic member abut against the barbs.

[0012] Furthermore, a support boss is provided at the middle position of one side of the two elastic plates, the outer diameter of the support boss is equal to the outer diameter of the first elastic member, and the two ends of the first elastic member are respectively sleeved on the two support bosses.

[0013] Furthermore, the limiting device is a limiting boss fixed on the cavity wall of the flow channel. When the elastic device does not deform, the two elastic plates abut against the two limiting bosses respectively.

[0014] Furthermore, a support is provided at the edge position of one of the opposite sides of the two elastic plates, and the support abuts against the cavity wall of the flow channel.

[0015] Furthermore, the plunger body includes a rod and a head, the rod and the head being an integral structure, and the head being connected to the drive mechanism in the plunger pump.

[0016] Furthermore, the two ends of the flow channel are respectively provided with an inlet hole and an outlet hole, the inlet hole being located at the end of the rod and the outlet hole being located at the end of the head.

[0017] The beneficial effects of this invention are:

[0018] 1. The present invention proposes a multi-stage adjustable plunger to reduce pulsation. Different oil pressure pulsations will cause different pressures on the surface of the elastic plate, thereby causing deformation of the elastic plate and the elastic element. It can achieve the effect under different pressure environments. Furthermore, the stiffness coefficient of the elastic element can be selected to meet the needs of different types of plunger pumps, thereby realizing the multi-stage adjustment function of oil pulsation.

[0019] 2. The present invention proposes a multi-stage adjustable plunger to reduce pulsation. Through the setting of the elastic plate, the elastic plate is a honeycomb mesh structure, and the oil can flow freely into and out of the elastic plate. It can also undergo elastic deformation to absorb energy, reduce oil pulsation through deformation, and absorb and evenly transmit the oil pulsation to the spring assembly.

[0020] 3. The multi-level adjustable plunger for reducing pulsation proposed in this invention, through the setting of the support body, is fixed to the edge of the elastic plate and can move back and forth with the elastic plate to play a reinforcing role.

[0021] 4. The present invention proposes a multi-level adjustable plunger to reduce pulsation. By setting a limiting device, the limiting boss is fixed on the plunger cavity wall to limit the maximum movement distance of the elastic plates at both ends. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of a multi-stage adjustable plunger for reducing pulsation according to the present invention.

[0024] Figure 2 This is a schematic diagram of the deformation of only the elastic plate of a multi-stage adjustable plunger for reducing pulsation according to the present invention.

[0025] Figure 3 This is a schematic diagram of a multi-stage adjustable plunger for reducing pulsation according to the present invention, which compresses only the first elastic element.

[0026] Figure 4 This is a schematic diagram of a multi-stage adjustable plunger for reducing pulsation, which simultaneously compresses the first and second elastic elements according to the present invention.

[0027] Figure 5 This is a comparison chart showing the effect of a multi-stage adjustable plunger for reducing pressure pulsation on suppressing pressure pulsation under different outlet pressures, according to the present invention.

[0028] In the figure, 10 is the plunger body; 101 is the flow channel; 102 is the head; 20 is the elastic plate; 201 is the filter hole; 301 is the first elastic element; 302 is the second elastic element; 401 is the support body; 402 is the limiting device; 403 is the support boss; and 404 is the fastener. Detailed Implementation

[0029] The following is combined Figure 1-5The present invention will be described in detail below.

[0030] A multi-stage adjustable pulsation-reducing plunger includes a plunger body 10, with a flow channel 101 inside the plunger body 10; at least two limiting devices 402 are sequentially provided in the flow channel 101; at least two elastic plates 20 are slidably connected between the two limiting devices 402 in the flow channel 101; an elastic device is provided between the two elastic plates 20; and at least two elastic elements are nested in the elastic device from the outside to the inside.

[0031] During the drainage process, the oil pressure pulsation causes pressure on the surface of the elastic plate 20, resulting in deformation of the elastic plate 20 and the elastic device. In the first pulsation stage, the deformation of the elastic plate decreases, and the elastic device is not compressed. In the second pulsation stage, one of the elastic elements of the elastic device is compressed. In the third pulsation stage, both elastic elements of the elastic device are compressed simultaneously. The first pulsation stage is a low-pulsation stage, the second pulsation stage is a medium-pulsation stage, and the third pulsation stage is a high-pulsation stage.

[0032] Specifically, the number of elastic elements nested from the outside in and the elastic coefficient can be adjusted according to the actual situation of the plunger. For example, if two elastic elements cannot effectively reduce pulsating energy, three or more elastic elements can be set.

[0033] like Figure 1 As shown, the outer surfaces of the two elastic plates 20 have a plurality of filter holes 201 arranged at equal intervals. The elastic plates 20 have a honeycomb structure, and the filter holes 201 should not be too small or too dense to allow oil to flow in and out freely. The elastic plates 20 themselves can deform to absorb a small amount of energy, thereby reducing pulsation. To meet the requirements of strength and elasticity, the elastic plates 20 can be made by laminating metal sheets and polyester sheets. The plunger cavity wall is provided with grooves, and the elastic plates 20 are embedded in the grooves and can slide. The depth of the grooves is set to be small.

[0034] In this embodiment, the elastic device is nested from the outside in with a first elastic element 301 and a second elastic element 302. The elastic coefficient of the first elastic element 301 is less than that of the second elastic element 302. The length and radius of the first elastic element 301 are the same as those of the second elastic element 302.

[0035] In this embodiment, mounting holes are provided in the middle of the two elastic plates 20, and fasteners 404 are installed in the mounting holes. The two ends of the second elastic member 302 are respectively fitted onto the two fasteners 404. A circular hole is opened in the middle of the two elastic plates 20 to install bolts and other fasteners 404. It should be noted that the diameter of the circular hole should be as small as possible to ensure sufficient oil flow on the surface of the elastic plate 20. The second elastic member 302 is fitted onto the fastener 404, and a barbed metal piece is embedded at the tail of the fastener 404 to prevent the second elastic member 302 from falling off the bolt when the plunger moves at high speed. Two support bosses 403 are fixed on the inner surface of each elastic plate 20, located at the same radius above and below the center of the elastic plate 20.

[0036] In this embodiment, the second elastic member 302 is interference-fitted with the fastener 404, the fastener 404 is provided with barbs, and the two ends of the second elastic member 302 abut against the barbs.

[0037] In this embodiment, a support boss 403 is provided at the middle of one side of the two elastic plates 20. The outer diameter of the support boss 403 is equal to the outer diameter of the first elastic member 301. The two ends of the first elastic member 301 are respectively fitted onto the two support bosses 403. The first elastic member 301 is fitted onto the support bosses 403, and an anti-slip material can be attached to the surface of the support bosses 403 to improve the stability of the device. Since the length of the first elastic member 301 is the maximum distance between the two elastic plates 20, there is no need to add protective measures to prevent it from falling off. The length of the first elastic member 301 is longer than that of the second elastic member 302, but the stiffness coefficient of the first elastic member 301 is smaller than that of the second elastic member 302. Therefore, when the oil pressure pulsation is small, the first elastic member 301 is compressed first, and when the pulsation is large, the first elastic member 301 and the second elastic member 302 are compressed together, realizing multi-stage control of oil pulsation.

[0038] Furthermore, the limiting device 402 is a limiting boss fixed on the cavity wall of the flow channel 101. When the elastic device does not deform, the two elastic plates 20 respectively abut against the two limiting bosses. The upper and lower cavity walls on the left side of the elastic plate 20 are fixed with limiting bosses to limit the maximum upward movement of the upper elastic plate 20, while the downward movement is unrestricted. The same applies to the lower elastic plate 20. In order to improve the stability of the elastic plate 20 when sliding left and right, wedge-shaped support bodies 401 are fixed on the upper and lower inner surfaces of the inner side of the elastic plate 20 to provide strong support. Preferably, in order to adapt to the high-intensity working environment inside the plunger cavity, the support body 401, the limiting device 402, the support boss 403, and the fastener 404 are made of metal with high strength and high wear resistance.

[0039] In this embodiment, a support 401 is provided at the edge of one side of the two elastic plates 20 facing each other, and the support 401 abuts against the cavity wall of the flow channel 101.

[0040] In this embodiment, the plunger body 10 includes a rod and a head 102, the rod and the head 102 are an integral structure, and the head 102 is connected to the drive mechanism in the plunger pump.

[0041] Furthermore, the two ends of the flow channel 101 are respectively provided with an inlet hole and an outlet hole, the inlet hole being located at the end of the rod and the outlet hole being located at the end of the head 102.

[0042] like Figure 2 As shown, when the plunger pump is working, the oil enters through the inlet, flows from the lower chamber through the lower elastic plate 20 into the middle chamber, and then from the middle chamber through the upper elastic plate 20 into the upper chamber and into the slipper. The oil flows from right to left. Figure 2 (As shown by the arrow direction), the direction of the oil pressure on the surface of the elastic plate 20 is also from bottom to top, and the elastic plate 20 tends to move upward. Under low pulsation conditions, the oil pressure is relatively small. Due to the friction between the elastic plate 20, the wedge-shaped support 401, and the cavity wall, the surface pressure is insufficient to move the elastic plate 20. The left and lower elastic plates 20 deform themselves in the direction of oil flow to absorb a small amount of pulsating energy. At this time, neither the inner nor the first elastic element 301 is compressed; only the elastic plate 20 itself deforms to reduce oil pulsation.

[0043] like Figure 3 As shown, under medium pulsation, the oil flows from the lower chamber through the lower elastic plate 20 into the middle chamber, and then from the middle chamber through the elastic plate 20 into the upper chamber. Due to the high oil pressure, the elastic plate 20 deforms to its maximum. At this point, the lower elastic plate 20 moves upward, reaching its maximum limit. The first elastic element 301 is compressed to provide support for the elastic plate 20, reducing oil pulsation. Since the supporting force provided by the portion of the first elastic element 301 that is longer than the second elastic element 302 is sufficient to neutralize the oil pulsation, the elastic plate 20 only compresses the first elastic element 301 while the length of the second elastic element 302 remains unchanged. In this case, the elastic plate 20 and the first elastic element 301 jointly participate in regulating the oil pulsation.

[0044] like Figure 4As shown, when the pulsation is large, the oil flows from the lower chamber through the lower elastic plate 20 into the middle chamber, and then from the middle chamber through the elastic plate 20 into the upper chamber. Due to the high oil pressure, the elastic plate 20 deforms to its maximum, and the lower elastic plate 20 moves to the left, reaching its maximum limit. At this time, the elastic force generated by the deformation of the elastic plate 20 itself and the supporting force provided by the portion of the first elastic element 301 that is longer than the second elastic element 302 are insufficient to neutralize the oil pressure fluctuations. When the first elastic element 301 is compressed to the same length as the second elastic element 302, both the inner and the first elastic element 301 are compressed simultaneously, and both provide supporting force for the elastic plate 20 to counteract the oil pulsation pressure. In this case, the elastic plate 20, the first elastic element 301, and the second elastic element 302 all participate in the regulation of oil pulsation, and the neutralizing force they can provide is much greater than in the previous two cases.

[0045] Furthermore, in order to select the spring size and spring constant more accurately, the specific relationship between the spring compression and the oil pulsation will be calculated below.

[0046] The pressure change in the plunger cavity can be expressed by the following formula: p is the pressure in the plunger cavity, K e It is the elastic modulus of hydraulic oil, V pc Q is the volume of the plunger cavity. lp Q is the volumetric flow rate from the plunger pump inlet to the plunger chamber. hp Q is the volumetric flow rate from the plunger cavity to the plunger pump outlet. l It is the volumetric flow rate leaking from each friction pair.

[0047] The volume of the plunger cavity can be expressed as: Where V is the volume of the plunger cavity when the plunger is at the outer dead point, θ is the plunger rotation angle, Dp is the plunger diameter, R is the radius of the plunger distribution circle, and β is the swashplate tilt angle.

[0048] The volumetric flow rate from the plunger pump inlet to the plunger chamber or from the plunger chamber to the plunger pump outlet can be expressed as: Where C is the flow coefficient, A lp A hp These are the flow areas between the plunger pump inlet and outlet and the plunger cavity, respectively, and their values ​​are determined by the structure of the distribution plate. ρ is the density of the hydraulic oil. l p h These are the pressures at the inlet and outlet of the plunger pump, respectively.

[0049] The pressure on the surface of the elastic plate 20 is: F = p * S; where S is the solid area of ​​the elastic plate 20.

[0050] When only the first elastic element 301 is compressed, the deformation of the first elastic element 301 is: X1 = F / k1; when the double spring is compressed, the deformation of the second elastic element 302 is: When the double spring is compressed, the deformation of the first elastic element 301 is: X1 = X + l1 - l2; where k1 and k2 are the spring constants of the first elastic element 301 and the second elastic element 302, respectively, and l1 and l2 are the original lengths of the first elastic element 301 and the second elastic element 302, respectively.

[0051] Pressure pulsation in an axial piston 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: Where, p max For maximum pressure, p min For minimum pressure, p avg This represents the average pressure.

[0052] like Figure 5 As shown, the pressure fluctuation rate increases with increasing outlet pressure. Under high pressure, the pressure feedback effect is more significant, leakage flow increases, oil compressibility becomes more pronounced, the distribution process becomes more complex, and mechanical deformation and hydrodynamic effects become more prominent. Furthermore, changes in system response characteristics, the influence of material properties, temperature variations, and potential resonance effects all exacerbate pressure fluctuations. These factors interact, leading to increased non-uniformity in piston movement, intensified flow fluctuations, and ultimately, an increase in pressure fluctuation rate with rising outlet pressure. Compared to the original plunger, the plunger of this invention can significantly reduce the outlet pressure pulsation rate of the axial plunger pump; the pressure pulsation suppression effect of the device of this invention is even more pronounced with increasing outlet pressure.

[0053] 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 multi-stage adjustable plunger for reducing pulsation, comprising a plunger body, characterized in that, The plunger body is provided with a flow channel inside; at least two limiting devices are arranged in sequence in the flow channel; at least two elastic plates are slidably connected between the two limiting devices; a number of filter holes are arranged equidistantly on the outer surfaces of the two elastic plates; an elastic device is provided between the two elastic plates; the elastic device includes at least two elastic elements nested in sequence from the outside to the inside. During the drainage process, the oil pressure pulsation causes pressure on the surface of the elastic plate, which in turn causes the elastic plate and the elastic device to deform. In the first pulsation stage, the deformation of the elastic plate reduces the pulsation, and the elastic device is not compressed. During the second pulsation phase, one of the elastic elements of the elastic device is compressed; during the third pulsation phase, both elastic elements of the elastic device are compressed simultaneously.

2. The multi-stage adjustable pulsation reduction plunger as described in claim 1, characterized in that, The elastic device is provided with a first elastic element and a second elastic element nested from the outside in. The elastic coefficient of the first elastic element is less than that of the second elastic element, and the length and radius of the first elastic element are greater than those of the second elastic element.

3. The multi-stage adjustable pulsation reduction plunger as described in claim 2, characterized in that, The two elastic plates are provided with mounting holes in the middle, and fasteners are provided in the mounting holes. The second elastic element is sleeved on the fasteners.

4. The multi-stage adjustable pulsation reduction plunger as described in claim 3, characterized in that, The second elastic element is interference-fitted with the fastener, the fastener is provided with barbs, and the two ends of the second elastic element abut against the barbs.

5. A multi-stage adjustable plunger for reducing pulsation as described in claim 2, characterized in that, A support boss is provided at the middle of one side of the two elastic plates. The outer diameter of the support boss is equal to the outer diameter of the first elastic member. The two ends of the first elastic member are respectively sleeved on the two support bosses.

6. A multi-stage adjustable pulsation-reducing plunger as described in claim 5, characterized in that, The limiting device is a limiting boss fixed on the cavity wall of the flow channel. When the elastic device does not deform, the two elastic plates abut against the two limiting bosses respectively.

7. A multi-stage adjustable plunger for reducing pulsation as described in claim 1, characterized in that, A support is provided at the edge of one of the opposite sides of the two elastic plates, and the support abuts against the cavity wall of the flow channel.

8. A multi-stage adjustable plunger for reducing pulsation as described in claim 1, characterized in that, The plunger body includes a rod and a head, the rod and the head being an integral structure, and the head being connected to the drive mechanism in the plunger pump.

9. A multi-stage adjustable pulsation-reducing plunger as described in claim 8, characterized in that, The flow channel is provided with an inlet hole and an outlet hole at both ends, with the inlet hole located at the end of the rod and the outlet hole located at the end of the head.

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