CN-122014580-A - Broadband pressure pulsation suppression plunger, axial plunger pump and working method of broadband pressure pulsation suppression plunger

CN122014580ACN 122014580 ACN122014580 ACN 122014580ACN-122014580-A

Abstract

The invention discloses a broadband pressure pulsation suppression plunger, an axial plunger pump and a working method thereof. The inside hollow plunger chamber that is equipped with of this plunger, the lateral wall in plunger chamber has arranged helmholtz resonant cavity and spring vibration absorbing unit along the axial, helmholtz resonant cavity is used for absorbing high frequency harmonic energy, spring vibration absorbing unit is used for absorbing low frequency vibration energy in grades. The invention realizes effective inhibition of broadband pressure pulsation through the synergistic effect of the Helmholtz resonant cavity and the spring vibration absorbing unit, and simultaneously realizes active evacuation of oil by utilizing gravity and spring restoring force, solves the problem that the traditional damping structure is easy to trap oil, and has the advantages of compact structure, self-adaptation response, thorough oil discharge and the like.

Inventors

YE SHAOGAN
CHEN JINLONG
XIA XIAOSONG
BAO YUE

Assignees

厦门大学

Dates

Publication Date: 20260512
Application Date: 20260327

Claims (10)

1. A broadband pressure pulsation suppression plunger is characterized by comprising a plunger body, wherein a hollow plunger cavity is formed in the plunger body, at least one array of Helmholtz resonant cavities is axially arranged on the side wall of the plunger cavity, the sizes of the Helmholtz resonant cavities in the same array are sequentially changed, a plurality of spring vibration absorbing units are axially and sequentially arranged at the bottom of the plunger cavity, each spring vibration absorbing unit comprises a piston, a spring and a limiting structure, and the equivalent stiffness of the spring is gradually reduced from a distance oil discharging end to a distance oil discharging end along the axial direction of the plunger cavity.
2. The broadband pressure pulsation suppression plunger according to claim 1, wherein the Helmholtz resonant cavity comprises a cavity body and a pore canal communicated with the plunger cavity, the central line of the pore canal is located in the radial direction of the plunger cavity, the cavity body is embedded in the side wall of the plunger cavity, and the sizes of the cavity body and the pore canal are sequentially increased from the position close to the oil suction end to the position far from the oil suction end.
3. A broadband pressure pulsation suppression plunger according to claim 2, wherein the structural parameters of the helmholtz resonator satisfy the following relationship: ; Wherein, the Is the resonance frequency of the wave-shaped resonator, Is the speed of sound, Is the volume of the cavity body and the volume of the cavity body, Is the effective length of the tunnel and, Is the cross-sectional area of the tunnel opening.
4. The broadband pressure pulsation suppression plunger according to claim 1, wherein a plurality of grooves are formed in the bottom of the plunger cavity, and the spring vibration absorbing unit is arranged in the grooves.
5. The broadband pressure pulsation suppression plunger according to claim 4, wherein the piston is slidably mounted in the groove, a surface of a side of the piston facing the plunger cavity is an arc surface or a plane, and an outer diameter of the piston and an inner diameter of the groove form an interference fit.
6. The broadband pressure pulsation suppression plunger according to claim 4, wherein the spring is disposed in a closed space on one side of the piston facing away from the plunger cavity, and two ends of the spring are respectively connected with bottoms of the piston and the groove.
7. The broadband pressure pulsation suppression plunger according to claim 4, wherein said limiting structure comprises a boss provided at the bottom of the piston, said boss being made of an elastic material.
8. An axial plunger pump characterized by comprising the broadband pressure pulsation suppression plunger according to any one of claims 1 to 7.
9. A method for realizing broadband pressure pulsation suppression is characterized in that the broadband pressure pulsation suppression plunger according to any one of claims 1-7 or an axial plunger pump according to claim 8 is adopted for oil suction and oil discharge of a hydraulic system.
10. The method for achieving broadband pressure pulsation suppression according to claim 9, comprising the steps of: S1, enabling oil to enter a plunger cavity and enter a Helmholtz resonant cavity arranged on the side wall of the plunger cavity during the oil suction stroke of a hydraulic system; S2, utilizing resonance acoustic characteristics of the Helmholtz resonant cavity at high-frequency resonance frequency in the coverage range of dimensional change to convert high-frequency pressure pulsation energy in the oil into heat energy and dissipate the heat energy; S3, during the oil discharge stroke, enabling oil to exert pressure on a spring vibration absorbing unit positioned at the bottom of the plunger cavity, pushing the piston to compress the spring, and realizing graded damping of low-frequency impact according to gradient stiffness of the spring; And S4, when the oil discharging stroke is finished, the stored potential energy of the spring is released, so that the piston is reset under the combined action of the spring reset force and gravity, the oil in the spring vibration absorbing unit is actively discharged back to the plunger cavity, dead volume oil is prevented from being detained, and active oil discharging is realized.

Description

Broadband pressure pulsation suppression plunger, axial plunger pump and working method of broadband pressure pulsation suppression plunger Technical Field The invention belongs to the technical field of vibration reduction and noise reduction of plunger pumps, and particularly relates to a broadband pressure pulsation suppression plunger, an axial plunger pump and a working method thereof. Background The axial plunger pump is a core power element of a hydraulic system, and is widely applied to the fields of automobiles, engineering machinery and equipment manufacturing by virtue of the advantages of compact structure, high power density, high working pressure and the like. During operation, the plunger cavity is periodically switched between the oil suction port and the oil discharge port along with the reciprocating motion of the piston. The momentary abrupt change in the volume of the cavity and the compressibility of the oil result in flow backflow and pressure shock, creating significant pressure pulsations. Such pulsations are a major source of hydraulic system vibration, noise, and critical component fatigue failure. The existing noise reduction measures are to set damping grooves on a valve plate, and the passive vibration suppression is realized by reducing the pressure change rate through throttling. However, the scheme has two major limitations that firstly, the damping groove is fixed in size and difficult to adapt to wide-range rotation speed and load change, reverse flow or pressure overshoot is easy to occur under a high-pressure working condition, and secondly, specific harmonic waves which enter a steady state are lack of targeted absorption, so that effective vibration suppression in a wide frequency range is difficult to realize. Therefore, there is an urgent need for an innovative plunger structure that can be integrated inside the plunger, has broadband shock absorbing capability, and has an adaptive adjustment function, so as to fundamentally eliminate pressure pulsation, reduce noise, and improve system reliability. Disclosure of Invention The invention aims to overcome the defects of the prior art, provides a broadband pressure pulsation suppression plunger, an axial plunger pump and a working method thereof, and solves the problems of narrow pressure pulsation suppression frequency band and poor self-adaptability of the plunger pump in the prior art. The technical scheme includes that the broadband pressure pulsation suppression plunger comprises a plunger body, wherein a hollow plunger cavity is formed in the plunger body, at least one row of Helmholtz resonant cavities are axially arranged on the side wall of the plunger cavity, the sizes of the Helmholtz resonant cavities in the same row are sequentially changed, a plurality of spring vibration absorption units are axially and sequentially arranged at the bottom of the plunger cavity, each spring vibration absorption unit comprises a piston, a spring and a limiting structure, and equivalent stiffness of the spring is gradually reduced from a distance oil discharge end to a distance oil discharge end along the axial direction of the plunger cavity so as to adapt to the working condition of larger pulsation near an outlet, and the pressure pulsation is buffered in a grading mode. In a preferred embodiment of the present invention, the helmholtz resonator includes a cavity and a duct communicated with the plunger cavity, wherein a center line of the duct is located in a radial direction of the plunger cavity, the cavity is embedded in a side wall of the plunger cavity, and sizes of the cavity and the duct are sequentially increased from being close to the oil absorption end to being far from the oil absorption end. In a preferred embodiment of the present invention, the structural parameters of the helmholtz resonator satisfy the helmholtz resonance frequency formula, and the resonance frequency of the helmholtz resonator corresponds to the main high frequency harmonic frequency in the oil pressure pulsation by designing different cavity volumes and pore channel sizes. Specifically, the method for calculating the resonant cavity parameters is as follows: The helmholtz resonator is generally composed of a closed cavity having a limited volume and a long and narrow passage communicating with the outside. When external sound waves act on the structure, under the low-frequency condition (the sound wave wavelength is far greater than the characteristic dimensions of the cavity and the pore canal), the sound pressure in the cavity can be approximately considered to be uniformly distributed in space, and the air in the pore canal integrally participates in vibration, so that the system shows typical single-degree-of-freedom resonance characteristics. Under the assumption of small-amplitude linear acoustics, the Helmholtz resonant cavity can be equivalently a mass-spring system, wherein the inertia of an air column in a pore canal correspon