Flow characteristic analysis method and system of axial constant-displacement vane pump

Abstract

The application discloses a kind of flow characteristics analysis method and system of axial quantitative vane pump, method includes: constructing the stator cam surface equation and blade cam surface equation of axial quantitative vane pump, determine parameter and draw to obtain blade three-dimensional model and stator cam surface model;Assembled model obtains blade-stator kinematic pair, calculates the volume of axial quantitative vane pump;Determine the working state and movement stage of axial quantitative vane pump, draw the two-dimensional model of blade-stator kinematic pair;Calculate the displacement of different movement states and movement stages, construct displacement mathematical calculation model and instantaneous flow and pulsation rate calculation model, establish the lumped parameter model of axial quantitative vane pump, carry out flow characteristic analysis to axial quantitative vane pump.By the technical scheme of the application, the derivation, simplification and calculation process are simplified, the flow characteristic parameters of axial quantitative vane pump can be quickly and accurately calculated, which provides a basis for optimizing the structure and performance parameters of axial quantitative vane pump.

Description

Technical Field

[0001] This invention relates to the field of fluid analysis technology, and in particular to a method for analyzing the flow characteristics of an axially metered vane pump and a system for analyzing the flow characteristics of an axially metered vane pump. Background Technology

[0002] With the progress and development of the times, mechanized production will become an inevitable trend in the development of the entire era. Looking at the current application status of automated production technology, modern hydraulic technology, as its core technology, plays an irreplaceable role in the operation of the entire automated production system. Hydraulic transmission is a transmission method that uses fluid as the working medium to transmit and control energy. Compared with other transmission forms, it has advantages such as large input force, compact structure, small size, convenient speed adjustment, and easy control, and is therefore widely used in engineering machinery, agricultural machinery, automobiles, ships, aerospace, and other fields. The hydraulic pump is the power component in a hydraulic system, an energy conversion device that converts the mechanical energy of the drive motor into pressure energy transmitted into the system. As the core component of the hydraulic system and the power source of the entire system, the performance of the hydraulic pump directly affects the performance, service life, and reliability of the hydraulic system.

[0003] Vane pumps offer advantages such as small size, light weight, uniform flow, and low noise. However, as they evolve towards higher speeds and higher pressures, the limitations of existing radial vane pump structures lead to increased pressure and peak pulsation in the vane root chamber. This results in increased radial force and pulsation amplitude on the vanes, further exacerbating radial vibration and worsening the contact characteristics between the vanes and the stator's inner surface. This not only intensifies wear on the vane tip and stator inner surface but also increases top clearance leakage. Furthermore, as speed and pressure increase, hydraulic shock and cavitation in the vane sealing volume during flow distribution and sealing transitions are aggravated, increasing internal leakage and worsening suction cavitation.

[0004] It is evident that high speed and high pressure will deteriorate the output performance of existing radial vane pumps, increase vibration, noise, reduce friction and lubrication performance, and increase leakage, thereby reducing the pump's volumetric efficiency and mechanical efficiency, increasing power loss, and decreasing efficiency. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a method and system for analyzing the flow characteristics of an axially metered vane pump. By constructing a three-dimensional model of the vane-stator kinematic pair with the vane surface and stator surface in close contact, the method effectively reduces vane wear and eliminates axial vibration of the vanes. Based on the working principle and internal suction and discharge conditions of the axially metered vane pump, the method analyzes the flow characteristics of the pump, simplifying the derivation, simplification, and calculation process. It can quickly and accurately calculate the flow characteristic parameters of the axially metered vane pump, providing a basis for optimizing the structure and performance parameters of the axially metered vane pump.

[0006] To achieve the above objectives, the present invention provides a method for analyzing the flow characteristics of an axially fixed displacement vane pump, comprising:

[0007] Construct the stator surface equation and blade surface equation of an axially fixed displacement vane pump;

[0008] The parameters of the blade surface equation and the stator surface equation are determined, and the three-dimensional model of the blade and the stator surface model are drawn in the three-dimensional modeling software.

[0009] The blade 3D model is assembled with the stator surface model to obtain the blade-stator kinematic pair;

[0010] Calculate the volume of the axially fixed displacement vane pump based on the volume parameters of the blade-stator kinematic pair.

[0011] Determine the working state and blade motion stage of the axial metering vane pump, and draw a two-dimensional model of the blade-stator kinematic pair;

[0012] The displacement of the axial metering vane pump under different motion states and motion stages is calculated based on the stator surface equation, and a mathematical calculation model for the displacement and a calculation model for the instantaneous flow rate and pulsation rate of the axial metering vane pump are constructed.

[0013] By combining the displacement mathematical calculation model and the instantaneous flow rate and pulsation rate calculation model, a lumped parameter model of the axial fixed displacement vane pump is established, and the flow characteristics of the axial fixed displacement vane pump are analyzed.

[0014] In the above technical solution, preferably, the blade type of the axial metering vane pump includes elliptical apex profile, triangular apex profile, triangular dome profile, chamfered apex profile, pointed apex profile, wedge-shaped arc apex profile, single arc apex profile and arc apex profile;

[0015] The derivation methods for the blade surface equation of elliptical blades include:

[0016] Establish a three-dimensional rectangular coordinate system for the blade, and make the blade symmetrical about the x-axis both vertically and horizontally.

[0017] The standard equation of the ellipse in the rectangular coordinate system is determined as follows:

[0018]

[0019] The equation of the ellipse placed in the x = r² section of the rectangular coordinate system is:

[0020]

[0021] The formulas for the upper elliptical surface, the middle sector region, and the lower elliptical surface of the blade at the x = r² section are derived as follows:

[0022]

[0023] The coordinates of any point on the blade are (x, y, z). The blade, viewed from above along the positive z-axis, appears as a fan-shaped surface, with the included angle being... The inner circle radius of the stator is r1, the outer circle radius of the stator is r2, the angle between any point on the blade and the x-axis is θ, the major axis of the ellipse on the x = r2 section of the blade is 2a, the minor axis is 2b, the overall height of the blade is H, and the radius of the sector region is R.

[0024] In the above technical solution, preferably, the stator curve of the axial metering vane pump includes a sine curve, an isostatic acceleration-isostatic deceleration curve, a quintic curve, and an octet curve.

[0025] The derivation method of the stator surface equation includes:

[0026] Equations for the stator helical surface and sector surface are established based on the surface of revolution and the helical surface.

[0027] Establish a three-dimensional rectangular coordinate system with the origin O on the central axis of the stator. The top view of the stator consists of four curved surfaces: the lower sector surface, the right helical surface, the upper sector surface, and the left helical surface.

[0028] The surface equation of the lower sector of the stator is calculated as follows:

[0029]

[0030] The surface equation of the right-hand helical surface of the stator is calculated as follows:

[0031]

[0032] The surface equation of the upper sector of the stator is calculated as follows:

[0033]

[0034] The upper sector-shaped surface lies on the plane z = T;

[0035] The surface equation of the left-hand helical surface of the stator is calculated as follows:

[0036]

[0037] In this context, the angle between the XOZ plane and the blade's plane of symmetry is α, representing the angle of rotation of the blade on the stator. The upper sector lies on the plane z = T, and the lower sector lies on the plane z = 0. The angles occupied by the upper and lower sectors are both α. The inner circle has a radius of r1, and the outer circle has a radius of r2.

[0038] In the above technical solution, preferably, the process of determining the parameters of the blade surface equation and the stator surface equation, and drawing the blade 3D model and the stator surface model in 3D modeling software, specifically includes:

[0039] Calculate the major and minor axes of the elliptical blade, and calculate the cross-sectional size of the blade at different positions;

[0040] Draw a sketch of the blade in 3D modeling software, and draw the cross-sections of the two distal ends of the blade;

[0041] Connect the two sections using the loft operation to generate a solid, draw the inner and outer circular surfaces of the blade, and use the extrude cut operation to cut out the inner and outer circular surfaces of the blade to obtain the three-dimensional model of the blade.

[0042] The parameters of the stator surface equation are determined, the stator surface equation is converted into a code language, the key parameters are determined and then entered into the program to obtain the point coordinates of the stator surface, forming a point set of the stator surface;

[0043] The stator surface point set is imported into the 3D modeling software to generate a stator curve. The stator curve is then subjected to feature stretching and scanning cut graphic processing to obtain a shaped stator surface model.

[0044] In the above technical solution, preferably, the three-dimensional model of the blade is assembled with the surface model of the stator to obtain a blade-stator kinematic pair. The specific process includes:

[0045] The upper and lower stators are set as fixed constraints, the outer surface of the drive shaft is fitted and constrained with the inner surface of the stator, and the rotating shaft is set to be rotatable.

[0046] The two sides of the blade are fitted together with the blade groove of the transmission shaft, and the blade motion constraint is set to obtain the blade-stator motion pair.

[0047] In the above technical solution, preferably, the volume of the axially fixed displacement vane pump is calculated based on the volume parameters of the blade-stator kinematic pair. The specific process includes:

[0048] Based on the volume parameters of the blade-stator kinematic pair and the symmetry of the stator structure, the volume of the axially fixed displacement vane pump is calculated as follows:

[0049]

[0050] In the above technical solution, preferably, the working state and movement stage of the axial metering vane pump are determined, and a two-dimensional model of the vane-stator kinematic pair is drawn. The specific process includes:

[0051] Based on the blade rotation angle α of the axial metering vane pump, the blade rotation angle during the first motion stage... The blades are located on the upper helical surface, and there are n oil suction chambers and n+1 oil discharge chambers;

[0052] During the second phase of motion, the blade rotation angle The blades are located in a fan-shaped planar region, with n oil suction chambers and n oil discharge chambers;

[0053] The blade rotation angle during the third motion stage The blade is located in the lower spiral region, where there are n+1 oil suction chambers and n oil discharge chambers;

[0054] The axial metering vane pump rotates one revolution of the vanes through 2n cycles, each cycle including the first motion phase, the second motion phase and the third motion phase;

[0055] The blade-stator kinematic pair is unfolded along the outer circular surface r2 of the stator to obtain a two-dimensional model of the blade-stator kinematic pair.

[0056] In the above technical solution, preferably, the displacement of the axially fixed displacement vane pump under different motion states and motion stages is calculated based on the stator surface equation, and a mathematical calculation model for the displacement and a calculation model for the instantaneous flow rate and pulsation rate of the axially fixed displacement vane pump are constructed. The specific process includes:

[0057] The ascending spiral PQ and descending spiral MN of the stator are calculated based on the stator surface equation.

[0058] In the first phase of motion There are n suction chambers and n+1 discharge chambers. The volume V1~V is calculated by subtracting the total volume of the n-1 blades on the upper part of the drive disc from the volume between the drive disc and the stator. n-1 And the volume V of the blade on the side of the oil suction chamber n where the plane of the nth blade is located and the contact line between the blade and the stator is located. n The displacement V of the axially fixed displacement vane pump in the first motion phase is obtained. Ⅰ ;

[0059] In the second phase of motion There are n oil suction chambers and n oil discharge chambers. The blades are located within the upper fan-shaped area. The volume V1~V is calculated by subtracting the blade volume from the volume between the drive disc and the stator. n The displacement V of the axial metering vane pump in the second motion phase is obtained. Ⅱ ;

[0060] In the third phase of motion There are n+1 oil suction chambers and n oil discharge chambers. The blades are located within the lower helical surface region. The volume V1~V is calculated by subtracting the volume of the n+1 blades from the volume between the drive disc and the stator. n+1 The displacement V of the axially fixed displacement vane pump in the third motion stage is obtained. Ⅲ ;

[0061] The mathematical model for calculating the displacement of the axially fixed displacement vane pump is as follows:

[0062] V = 2n(V max -V min )×2

[0063] Where n is the number of leaf pairs, V max V represents the maximum sealed cavity volume within a volume change cycle. min The minimum sealed cavity volume value within one volume change cycle;

[0064] Calculate the instantaneous flow rate q of the axial metering vane pump based on the rotational angular velocity and rotational speed of the drive shaft. in for:

[0065]

[0066] Where α is the angle of the blade;

[0067] Based on the regular variation characteristics of the instantaneous flow rate of the axially fixed displacement vane pump during oil suction and discharge, the flow rate pulsation is calculated as follows:

[0068]

[0069] Where max(q) in ) represents the maximum instantaneous flow rate, min(q) in ) represents the minimum instantaneous flow rate, q t This represents the average theoretical flow rate.

[0070] In the above technical solution, preferably, a lumped parameter model of the axially fixed displacement vane pump is established, and the flow characteristics of the axially fixed displacement vane pump are analyzed. The specific process includes:

[0071] By integrating the displacement mathematical calculation model and the instantaneous flow rate and pulsation rate calculation model, the lumped parameter model of the axial fixed displacement vane pump is obtained.

[0072] Based on the lumped parameter model, the influence characteristics of the sector angle, blade occupancy angle, stator inner circle radius, and stator outer circle radius on the displacement and pulsation rate of the axial metering vane pump are analyzed.

[0073] This invention also proposes a flow characteristic analysis system for an axially fixed displacement vane pump, applicable to the flow characteristic analysis method for an axially fixed displacement vane pump disclosed in any of the above technical solutions, comprising:

[0074] The surface equation construction module is used to construct the stator surface equation and blade surface equation of an axially fixed displacement vane pump.

[0075] The 3D model construction module is used to determine the parameters of the blade surface equation and the stator surface equation, and to draw the 3D model of the blade and the stator surface model in the 3D modeling software.

[0076] The motion model assembly module is used to assemble the three-dimensional model of the blade with the surface model of the stator to obtain the blade-stator motion pair;

[0077] The pump volume calculation module is used to calculate the volume of the axial metering vane pump based on the volume parameters of the blade-stator kinematic pair.

[0078] The motion state analysis module is used to determine the working state and motion stage of the axial metering vane pump, and to draw a two-dimensional model of the vane-stator kinematic pair.

[0079] The calculation model construction module is used to calculate the displacement of the axial fixed displacement vane pump under different motion states and motion stages based on the stator surface equation, and to construct the displacement mathematical calculation model and instantaneous flow rate and pulsation rate calculation model of the axial fixed displacement vane pump.

[0080] The flow characteristic analysis module is used to combine the displacement mathematical calculation model and the instantaneous flow rate and pulsation rate calculation model to establish the lumped parameter model of the axial quantitative vane pump and perform flow characteristic analysis on the axial quantitative vane pump.

[0081] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0082] (1) The blade surface of the axial metering vane pump is closely fitted with the stator surface. There are no sudden changes in velocity and acceleration during the blade movement, which can effectively reduce blade wear, eliminate vibration of the axial movement of the blade, and reduce blade wear and noise of the axial metering vane pump.

[0083] (2) The three-dimensional and two-dimensional models of the blade-stator kinematic pair established in this invention better demonstrate the working principle of the axial quantitative vane pump and its internal suction and discharge conditions, laying the foundation for the flow characteristic analysis of the vane pump.

[0084] (3) The calculation method for the flow characteristics of the axially fixed displacement vane pump proposed in this invention can be directly applied to the formula, which simplifies the derivation, simplification and calculation process. The operation process is simple and can quickly and accurately obtain the flow performance parameters of the axially fixed displacement vane pump, providing a basis for optimizing the structure and performance parameters of the axially fixed displacement vane pump. Attached Figure Description

[0085] Figure 1 This is a flowchart illustrating a method for analyzing the flow characteristics of an axially fixed displacement vane pump according to an embodiment of the present invention.

[0086] Figure 2 This is a schematic diagram of a blade top profile type disclosed in one embodiment of the present invention;

[0087] Figure 3 This is a schematic diagram illustrating the blade polar coordinate system and variables according to an embodiment of the present invention;

[0088] Figure 4 This is a schematic diagram of the stator coordinate system and stator surface disclosed in one embodiment of the present invention;

[0089] Figure 5 This is a schematic diagram of a two-dimensional and a three-dimensional model of a blade-stator kinematic pair disclosed in an embodiment of the present invention;

[0090] Figure 6 The two-dimensional model corresponding to the blade-stator kinematic pair disclosed in one embodiment of the present invention is shown in A schematic diagram of the suction and discharge process;

[0091] Figure 7 The two-dimensional model corresponding to the blade-stator kinematic pair disclosed in one embodiment of the present invention is shown in A schematic diagram of the suction and discharge process;

[0092] Figure 8 The two-dimensional model corresponding to the blade-stator kinematic pair disclosed in one embodiment of the present invention is shown in A schematic diagram of the suction and discharge process. Detailed Implementation

[0093] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0094] The present invention will now be described in further detail with reference to the accompanying drawings:

[0095] like Figure 1 As shown, a method for analyzing the flow characteristics of an axially fixed displacement vane pump according to the present invention includes:

[0096] Construct the stator surface equation and blade surface equation of an axially fixed displacement vane pump;

[0097] The parameters of the blade surface equation and stator surface equation are determined, and the 3D model of the blade and the stator surface model are drawn in 3D modeling software.

[0098] The blade 3D model is assembled with the stator surface model to obtain the blade-stator kinematic pair;

[0099] Calculate the volume of the axially fixed displacement vane pump based on the volume parameters of the blade-stator kinematic pair;

[0100] Determine the working state and blade motion stages of the axially fixed displacement vane pump, and draw a two-dimensional model of the vane-stator kinematic pair;

[0101] The displacement of the axial fixed displacement vane pump under different motion states and stages is calculated based on the stator surface equation. A mathematical calculation model for the displacement of the axial fixed displacement vane pump and a calculation model for the instantaneous flow rate and pulsation rate are constructed.

[0102] By combining the displacement mathematical calculation model and the instantaneous flow rate and pulsation rate calculation model, a lumped parameter model of the axial fixed displacement vane pump is established, and the flow characteristics of the axial fixed displacement vane pump are analyzed.

[0103] In this embodiment, by constructing a three-dimensional model of the blade-stator kinematic pair with the blade surface and stator surface closely fitted, blade wear is effectively reduced and blade axial motion vibration is eliminated. Based on the working principle and internal suction and discharge conditions of the axial metered vane pump, the flow characteristics of the vane pump are analyzed, simplifying the derivation, simplification and calculation process. The flow characteristic parameters of the axial metered vane pump can be calculated quickly and accurately, providing a basis for optimizing the structure and performance parameters of the axial metered vane pump.

[0104] In the implementation process, to explore the theoretical working performance of the axially fixed displacement vane pump and provide a basis for its structural optimization, a flow characteristic analysis method based on three-dimensional modeling was proposed. Using a three-dimensional model of the vane-stator kinematic pair and based on calculus geometry theory and Mathematica numerical calculation methods, a lumped parameter model for the flow characteristic analysis of the axially fixed displacement vane pump was established. The flow characteristic analysis of the axially fixed displacement vane pump mainly includes methods for calculating its volume, displacement, instantaneous flow rate, and pulsation rate.

[0105] Specifically, the blade type and stator curve type are selected first, and then the stator surface equation and blade surface equation of the axially fixed displacement vane pump are derived.

[0106] like Figure 2 As shown, in the above embodiments, preferably, the blade type of the axial metering vane pump includes elliptical apex profile, triangular apex profile, triangular dome profile, chamfered apex profile, pointed apex profile, wedge-shaped arc apex profile, single arc apex profile, and arc apex profile.

[0107] like Figure 3 As shown, in this embodiment, an elliptical blade is preferably used, and the derivation method of its blade surface equation includes:

[0108] Establish a three-dimensional rectangular coordinate system for the blade, with the coordinates of any point on the blade being (x, y, z), and make the blade symmetrical about the x-axis both vertically and horizontally.

[0109] The standard equation of an ellipse in a rectangular coordinate system is determined as follows:

[0110]

[0111] Placing the ellipse on the x = r² section in the rectangular coordinate system of the aforementioned blade, its equation is expressed as:

[0112]

[0113] The formula for the upper elliptical surface ADHE of the blade at the x = r² section is derived as follows:

[0114]

[0115] The formula for the middle sector region ABCDEFGH is:

[0116]

[0117] The formula for the lower elliptical surface BCGF on the x = r² section is:

[0118]

[0119] The blade, viewed from above along the positive z-axis, appears as a fan-shaped surface, with the included angle occupied by the blade being... The inner circle radius of the stator is r1, the outer circle radius of the stator is r2, the angle between any point on the blade and the x-axis is θ, the major axis of the ellipse on the x = r2 section of the blade is 2a, the minor axis is 2b, the overall height of the blade is H, and the radius of the sector region is R.

[0120] In the above embodiments, preferably, the stator curve of the axially displaced vane pump includes a sine curve, an isostatic acceleration-isostatic deceleration curve, a quintic curve, and an octet curve.

[0121] like Figure 4 As shown, in this embodiment, a fifth-order stator curve is preferably used, and the derivation method of the stator surface equation includes:

[0122] Equations for the stator helical surface and sector surface are established based on the surface of revolution and the helical surface.

[0123] Establish a three-dimensional rectangular coordinate system with the origin O on the central axis of the stator. The top view of the stator consists of four surfaces: the lower sector surface AEHD, the right helical surface ABFE, the upper sector surface BCGF, and the left helical surface CDHG.

[0124] The surface equation for the lower sector surface AEHD of the stator is calculated as follows:

[0125]

[0126] The lower sector lies on the plane where z = 0;

[0127] The surface equation of the right-hand helical surface ABFE of the stator is calculated as follows:

[0128]

[0129] The surface equation for the upper sector surface BCGF of the stator is:

[0130]

[0131] The upper sector lies on the plane z = T;

[0132] The surface equation for the left-hand helical surface CDHG of the stator is calculated as follows:

[0133]

[0134] In this context, the angle between the XOZ plane and the blade's plane of symmetry is α, representing the angle of rotation of the blade on the stator. The upper sector lies on the plane z = T, and the lower sector lies on the plane z = 0. The angles occupied by the upper and lower sectors are both α. The inner circle has a radius of r1, and the outer circle has a radius of r2.

[0135] In the above embodiment, preferably, the parameters of the blade surface equation and the stator surface equation are determined, and the three-dimensional model of the blade and the stator surface model are drawn in three-dimensional modeling software. The specific process includes:

[0136] Calculate the major and minor axes of the elliptical blade to determine the cross-sectional size of the blade at different positions;

[0137] Draw a sketch of the blade in 3D modeling software, and draw the cross-sections of the two distal ends of the blade;

[0138] Use the loft operation to connect the two sections to generate a solid, draw the inner and outer circular surfaces of the blade, and use the extrude cut operation to cut out the inner and outer circular surfaces of the blade to obtain the three-dimensional model of the blade.

[0139] Determine the parameters of the stator surface equation, convert the stator surface equation into a code language. Taking Matlab as an example, specify the parameters in the stator surface equation and convert them into Matlab code language. After determining the key parameters, input them into the program to obtain the point coordinates of any point on the stator surface, forming a stator surface point set.

[0140] The stator surface point set is imported into 3D modeling software to generate stator curves. The stator curves are then subjected to feature stretching and scanning cut graphic processing to obtain a shaped stator surface model.

[0141] To import the curve generated by the formula into 3D drawing software, the curve needs to be divided into several points, and the spatial coordinates of each point need to be recorded and saved as a txt file. Taking SolidWorks as an example of 3D modeling software, firstly, the point set txt file is imported into SolidWorks to generate a sketch curve, which serves as the reference curve for subsequent stator surface modeling. Based on the selected radii r1 and r2 of the inner and outer circular surfaces of the stator, a sketch is drawn, and an extrusion operation is performed to generate a 3D cylinder. Finally, based on the cylinder and using the imported sketch curve as the reference curve, a sweep cut operation with a specified direction vector is performed, thus completing the formation of the stator surface model.

[0142] like Figure 5 As shown, in the above embodiment, preferably, the three-dimensional model of the blade is assembled with the surface model of the stator to obtain the blade-stator kinematic pair. The specific process includes:

[0143] The upper and lower stators are set as fixed constraints, meaning that the upper and lower stators cannot move. The outer surface of the drive shaft is fitted and constrained with the inner surface of the stator, and the rotating shaft is set to be rotatable.

[0144] By fitting the two sides of the blade to the blade slot of the drive shaft and setting blade motion constraints, a blade-stator kinematic pair is obtained.

[0145] During the rotation of the drive shaft, the blades follow the drive shaft in a rotary motion. At the same time, due to the constraints of the upper and lower stators, the blades move axially between the stators.

[0146] In the above embodiments, preferably, the volume of the axially fixed displacement vane pump is calculated based on the volume parameters of the blade-stator kinematic pair. The specific process includes:

[0147] Based on the volume parameters of the blade-stator kinematic pair and the symmetry of the stator structure, the volume of the axially fixed displacement vane pump is calculated as follows:

[0148]

[0149] like Figures 6 to 8 As shown, in the above embodiment, preferably, in the process of determining the working state and movement stage of the axial metering vane pump, for an axial metering vane pump with n pairs of vanes, according to the analysis of its internal suction and discharge oil chambers, the vanes can be divided into three stages during the process of rotating 180° / n.

[0150] The specific process includes:

[0151] Based on the blade rotation angle α of the axially fixed displacement vane pump, the blade rotation angle during the first motion stage... The blades are located on the upper helical surface, and there are n oil suction chambers and n+1 oil discharge chambers;

[0152] During the second phase of motion, the blade rotation angle The blades are located in a fan-shaped planar region, with n oil suction chambers and n oil discharge chambers;

[0153] The blade rotation angle during the third motion stage The blade is located in the lower spiral region, where there are n+1 oil suction chambers and n oil discharge chambers.

[0154] The above three motion stages constitute one cycle of blade rotation. Each cycle includes the first motion stage, the second motion stage, and the third motion stage. The blade of the axial fixed displacement vane pump undergoes 2n cycles for one rotation.

[0155] To facilitate the establishment of the subsequent mathematical model, the blade-stator kinematic pair is unfolded along the outer circular surface r2 of the stator, and a two-dimensional model of the blade-stator kinematic pair is drawn.

[0156] In the above embodiment, preferably, the stator's ascending spiral PQ and descending spiral MN are calculated based on the stator surface equation:

[0157]

[0158] like Figures 6 to 8As shown, in the first stage of motion There are n suction chambers and n+1 discharge chambers. The volume V1~V is calculated by subtracting the total volume of the n-1 blades on the upper part of the drive disc from the volume between the drive disc and the stator. n-1 And the volume V of the blade on the side of the oil suction chamber n where the plane of the nth blade is located and the contact line between the blade and the stator is located. n The displacement V of the axially fixed displacement vane pump in the first motion stage is obtained. Ⅰ .

[0159] Specifically, the displacement V in the first stage of motion Ⅰ The calculation formula is:

[0160]

[0161] The volumes of the n subtracted leaves are as follows:

[0162]

[0163] ...

[0164]

[0165] Second phase of movement There are n oil suction chambers and n oil discharge chambers. The blades are located within the upper fan-shaped area. The volume V1~V is calculated by subtracting the blade volume from the volume between the drive disc and the stator. n The displacement V of the axially fixed displacement vane pump in the second motion stage is obtained. Ⅱ Excluding the blades, the volume to be calculated can be divided into two parts: one part is the maximum volume included by the upper helical surface, denoted as V. Ⅰ max is part of the volume from the starting surface of the sector region to the center surface of the blade.

[0166] Specifically, the displacement V in the second stage of motion Ⅱ The calculation formula is:

[0167]

[0168] The volumes of the nth leaf that were subtracted are as follows:

[0169]

[0170] ...

[0171]

[0172] In the third stage of movement There are n+1 oil suction chambers and n oil discharge chambers. The blades are located within the lower helical surface region. The volume V1~V is calculated by subtracting the volume of the n+1 blades from the volume between the drive disc and the stator. n+1The displacement V of the axially fixed displacement vane pump in the third motion stage is obtained. Ⅲ Excluding the blades, the volume to be calculated can be divided into three parts: the maximum volume contained in the upper helical surface, the maximum volume contained in the sectoral surface, and the volume involved in the lower helical surface.

[0173] As the number of oil suction chambers increases, the volume of the blades to be subtracted increases to n+1. Since the blades are spaced 180° / n apart, and the angle between the ends of the two oil grooves is equal to the angle between the two blades, only one blade related to the oil suction chamber will be in the lower spiral region, while the remaining blades will be in the upper spiral region.

[0174] Specifically, the displacement V in the third stage of motion Ⅲ The calculation formula is:

[0175]

[0176] Because the heights of the upper and lower spiral surfaces are related Symmetry means that the height of the (n+1)th leaf vertex is related to the height of the leaf in π-(α) max The vertex height is equal at the position of -π). Therefore, the volumes of the subtracted n+1 blades are respectively:

[0177]

[0178] ...

[0179]

[0180] When the blade position α is small, a portion of the blade's elliptical arc surface will be below the drive disk surface, resulting in a negative integral. To simplify calculations, this portion of the volume is recorded as zero. One cycle is 180° / n, and there are 2n oil suction and discharge cycles per revolution of the blade. Displacement V refers to the theoretically achievable (or required to be input) volume of oil per revolution, without considering leakage. The mathematical model for calculating the displacement of the axially fixed displacement vane pump is as follows:

[0181] V = 2n(V max -V min )×2

[0182] Where n is the number of leaf pairs, V max V represents the maximum sealed cavity volume within a volume change cycle. min The minimum sealed cavity volume value within one volume change cycle;

[0183] Calculate the instantaneous flow rate q of the axial fixed displacement vane pump based on the rotational angular velocity ω and rotational speed m of the drive shaft. in (L / min) is:

[0184]

[0185] Where α is the angle of the blade.

[0186] During the oil suction and discharge processes of an axial vane pump, the instantaneous flow rate will repeatedly change according to the same pattern, which is called flow pulsation. Based on the regular change characteristics of the instantaneous flow rate during the oil suction and discharge processes of an axial fixed displacement vane pump, the flow pulsation is calculated as follows:

[0187]

[0188] Where max(q) in ) represents the maximum instantaneous flow rate, min(q) in ) represents the minimum instantaneous flow rate, q t This represents the average theoretical flow rate.

[0189] Specifically, in the first phase The interior can be represented as:

[0190]

[0191] Phase Two The interior can be represented as:

[0192]

[0193] In the third stage The interior can be represented as:

[0194]

[0195] In the above embodiments, preferably, a lumped parameter model of the axially fixed displacement vane pump is established, and the flow characteristics of the axially fixed displacement vane pump are analyzed. The specific process includes:

[0196] By integrating the displacement mathematical calculation model and the instantaneous flow rate and pulsation rate calculation model, the lumped parameter model of the axial fixed displacement vane pump is obtained.

[0197] Analyze the sector angle based on the lumped parameter model. blade occupancy angle The influence characteristics of the inner circular surface radius r1 and the outer circular surface radius r2 of the stator on the displacement and pulsation rate of the axial fixed displacement vane pump.

[0198] Based on the flow characteristic analysis method of the axially fixed displacement vane pump disclosed in the above embodiments, the following uses two pairs of axially fixed displacement vane pumps as examples to specifically explain the method.

[0199] Step 1: Based on spatial meshing theory and the three-dimensional blade-stator kinematic pair, analyze the kinematic characteristics of the blade and the interference state of the blade within the kinematic pair. Taking all factors into consideration, an elliptical blade and a fifth-order stator curve are selected in this invention.

[0200] Step 2, taking the values ​​of each key parameter of the axial vane pump selected in Table 1 as an example.

[0201] Table 1 Dimensional parameters of axial vane pumps

[0202]

[0203] Substituting into the blade surface formula, we can obtain the formula for the elliptical surface ADHE on the x = r² section of the blade as follows:

[0204]

[0205] The formula for the middle sector region ABCDEFGH is:

[0206]

[0207] The formula for the lower elliptical surface BCGF on the x = r² section is:

[0208]

[0209] Step 3: Based on the values ​​of the key parameters of the axial vane pump selected in Table 1, substituting these parameters into the stator surface equation yields the first segment of the surface, which is the lower sector surface AEHD. The surface equation can be expressed as:

[0210]

[0211] The second surface segment is a right-hand helical surface ABFE, and its equation can be expressed as:

[0212]

[0213] The third surface segment is the upper sector surface BCGF, and its equation can be expressed as:

[0214]

[0215] The fourth surface is a left-handed helical surface CDHG, and its equation can be expressed as:

[0216]

[0217] Step 4: Based on the selected arc-shaped top profile blade from Step 1 and the blade surface equation established in Step 2, the cross-sectional size of the blade is obtained. Using SolidWorks 3D modeling software, a coordinate system and reference plane are established, and a sketch is drawn. The cross-sections at the two distal ends of the blade are drawn. Using the loft operation in SolidWorks 3D modeling software, the two cross-sections are connected to generate a solid. Finally, the inner and outer circular surfaces of the blade are drawn, and the extrusion cut operation is used to cut out the inner and outer circular surfaces of the blade. Thus, the 3D modeling of the blade is completed.

[0218] Step 5: Using Matlab, the parameters in the stator surface equation derived in Step 3 are concretized and converted into Matlab code, thus obtaining the stator outer contour curve and stator surface, and subsequently the position coordinates of any point on the stator surface. To import the curve / surface coordinates into SolidWorks 3D modeling software, the curve needs to be divided into several points, the spatial coordinates of each point are recorded, and finally saved as a txt file.

[0219] Step 6: First, import the point set txt file saved in Step 5 using SolidWorks 3D modeling software to generate the stator outer contour curve, which serves as the reference curve for subsequent stator surface modeling. Then, based on the selected radii r1 and r2 of the inner and outer surfaces of the stator, draw a sketch and perform an extrusion operation to generate a 3D cylinder. Finally, based on the cylinder and using the imported sketch curve as the reference curve, perform a sweep cut operation with a specified direction vector to complete the forming of the stator surface.

[0220] Step 7: Based on steps 4 and 6, firstly, use SolidWorks 3D modeling software to complete the 3D modeling of the upper and lower stators, blades, and drive shaft; secondly, use SolidWorks 3D modeling software to assemble the components of the blade-stator kinematic pair, and set the upper and lower stators as fixed constraints, that is, the upper and lower stators cannot move.

[0221] Then, the outer surface of the drive shaft is fitted and constrained with the inner surface of the stator, and the rotating shaft is set to be rotatable; finally, the two sides of the blade are fitted with the blade groove of the drive shaft, and the blade motion is constrained.

[0222] In summary, as the drive shaft rotates, the blades follow the drive shaft in a rotary motion. Simultaneously, due to the constraints of the upper and lower stators, the blades move axially between the stators. This completes the establishment of the blade-stator kinematic pair.

[0223] Step 8: Based on the symmetry of the blade-stator kinematic pair and the stator structure established in Step 7, the volume of the axial vane pump can be expressed as:

[0224]

[0225] Step 9, taking a two-pair axial fixed displacement vane pump as an example, based on the analysis of its internal suction and discharge chambers, the vane rotation of 90° can be divided into three stages. The vane rotation angle is α. Stage 1 is 135°≤α≤172°, the vane is on the upper helical surface, with 2 suction chambers and 3 discharge chambers; Stage 2 is 172°≤α≤188°, the vane is in the fan-shaped planar region, with 2 suction chambers and 2 discharge chambers; Stage 3 is 188°≤α≤225°, the vane is in the lower helical region, with 3 suction chambers and 2 discharge chambers. These three stages constitute one cycle of vane rotation, and the vane undergoes 4 cycles during one complete rotation.

[0226] Step 10: To facilitate the establishment of the subsequent mathematical model, unfold the blade-stator kinematic pair along the outer circle of the stator by 25mm and draw a two-dimensional model of the blade-stator kinematic pair.

[0227] Step 11: Substituting the specific values ​​from Table 1 into the displacement calculation model yields the following:

[0228] When the blade rotation angle is between 135°≤α≤172°, the upper stator and the blade form two oil suction chambers and three oil discharge chambers.

[0229] As the blades rotate, oil enters the suction chambers 1 and 2 through the inlet, increasing their volume. Simultaneously, oil in the discharge chambers 4, 5, and 6 is discharged from the pump under pressure through the outlet. When the blade rotation angle is α = 135°, the volume of oil in suction chambers 1 and 2 is 1485.109 mm³. 3 When the blade rotation angle is α = 172°, the oil volume in oil suction chambers 1 and 2 reaches its maximum of 2685.351 mm. 3 That is, the volume of oil drawn into oil suction chambers 1 and 2 during this stage is 1200.242 mm. 3 .

[0230] When the blade rotation angle is between 172°≤α≤188°, the upper stator and the blade form two oil suction chambers and two oil discharge chambers.

[0231] As the blades rotate, oil enters the suction chambers 1 and 2 through the inlet, and the volume of the suction chambers continuously increases. Simultaneously, oil in the discharge chambers 3 and 4 is discharged from the pump through the discharge port under pressure. When the blade rotation angle is α = 188°, the oil volume in suction chambers 1 and 2 reaches its maximum of 3207.392 mm³. 3 That is, during this stage, the volume of oil drawn into oil suction chambers 1 and 2 is 522.041 mm³. 3 .

[0232] When the blade rotation angle is between 188°≤α≤225°, the upper stator and the blade form 3 oil suction chambers and 2 oil discharge chambers.

[0233] As the blades rotate, oil enters the suction chambers 1, 2, and 3 through the inlet, and the volume of the suction chambers continuously increases. Simultaneously, oil in the discharge chambers 3 and 4 is discharged from the pump through the outlet under pressure. When the blade rotation angle is α = 225°, the oil volume in suction chambers 1, 2, and 3 reaches its maximum of 4407.636 mm³. That is, in this stage, suction chambers 1 and 2 draw in 1200.242 mm³ of oil.

[0234] In summary, the displacement of an axially fixed displacement vane pump can be expressed as:

[0235] V = 8(V max -V min = 23.38ml / r

[0236] Step 12: Based on the established displacement mathematical model, and setting the rotational speed of the axial vane pump to 1000 rpm, substituting the specific values ​​into the formula yields:

[0237] When the blade rotation angle is between 135° and 172°, the instantaneous flow rate is minimum at 22.3043 L / min when the blade rotation angle α = 135°. As the blade rotation angle increases, the instantaneous flow rate reaches maximum at 23.6673 L / min when the blade rotation angle α = 160.75°. Subsequently, the instantaneous flow rate decreases as the blade rotation angle decreases, reaching 23.5389 L / min when the blade rotation angle α = 172°.

[0238] When the blade rotation angle is between 172° and 188°, the instantaneous flow rate is maximum at 172°, reaching 23.5389 L / min. As the blade rotation angle increases, the instantaneous flow rate decreases, reaching minimum at 180°, where the instantaneous pulsation rate is 23.4682 L / min. The overall trend shows symmetry about 180°.

[0239] When the blade rotation angle is between 188° and α, and 225°, the instantaneous flow rate is 23.5389 L / min when the blade rotation angle α = 188°. As the blade rotation angle increases, the instantaneous flow rate increases, reaching a maximum of 23.6673 L / min when the blade rotation angle α = 199.25°. As the blade rotation angle increases, the instantaneous flow rate decreases, reaching a minimum of 23.3043 L / min when α = 225°.

[0240] In summary, the pulsation rate of the axially fixed displacement vane pump can be expressed as:

[0241]

[0242] Step 13: Based on the mathematical calculation model established in Steps 11 and 12 above, a lumped parameter model of the flow characteristics of the axially fixed displacement vane pump is established, thereby obtaining the influence of key parameters on the flow characteristics of the axially fixed displacement vane pump.

[0243] As the angle occupied by the sector surface increases, the displacement of the axial vane pump continuously increases, while the pulsation rate continuously decreases. The maximum displacement is 23.42 ml / r, and the minimum is 23.23 ml / r, a difference of only 0.19 ml / r; the maximum pulsation rate is 8.78%, and the minimum is 4.96%, a difference of 3.82%.

[0244] As the lead increases, the displacement of the axial vane pump continuously increases, while the pulsation rate remains constant. The maximum displacement is 31.17 ml / r, and the minimum is 15.59 ml / r, a difference of 15.58 ml / r; the pulsation rate is 5.829%. The stator lead has a significant impact on the axial vane pump, exhibiting an approximately linear relationship; however, it has no effect on the magnitude of the pulsation rate.

[0245] As the blade occupancy angle increases, the displacement and pulsation rate of the axial vane pump decrease continuously. The maximum displacement is 25.05 ml / r, and the minimum is 21.15 ml / r, a difference of 3.9 ml / r; the maximum pulsation rate is 6.95%, and the minimum is 4.33%, a difference of 2.62%. The blade occupancy angle has a relatively small impact on the displacement and pulsation rate of the axial vane pump, and exhibits a linear decreasing characteristic.

[0246] As the inner radius increases, the displacement of the axial vane pump decreases continuously, while the pulsation rate remains constant. The maximum displacement is 28.63 ml / r, and the minimum is 10.94 ml / r, a difference of 17.69 ml / r; the pulsation rate is 5.829%. The inner radius of the stator has a significant impact on the displacement of the axial vane pump, and this impact becomes more pronounced as the inner radius increases; however, it has no effect on the magnitude of the pulsation rate.

[0247] As the outer radius increases, the displacement of the axial vane pump continuously increases, while the pulsation rate remains constant. The maximum displacement is 42.77 ml / r, and the minimum is 8.75 ml / r, a difference of 34.02 ml / r; the pulsation rate is 5.829%. The outer radius of the stator has a significant impact on the displacement of the axial vane pump, and this impact becomes more pronounced as the outer radius increases; however, it has no effect on the magnitude of the pulsation rate.

[0248] This invention also proposes a flow characteristic analysis system for an axially fixed displacement vane pump, applicable to the flow characteristic analysis method for an axially fixed displacement vane pump disclosed in any of the above embodiments, comprising:

[0249] The surface equation construction module is used to construct the stator surface equation and blade surface equation of an axially fixed displacement vane pump.

[0250] The 3D model building module is used to determine the parameters of the blade surface equation and the stator surface equation, and to draw the 3D model of the blade and the stator surface model in the 3D modeling software.

[0251] The motion model assembly module is used to assemble the three-dimensional model of the blade with the surface model of the stator to obtain the blade-stator motion pair;

[0252] The pump volume calculation module is used to calculate the volume of the axially fixed displacement vane pump based on the volume parameters of the blade-stator kinematic pair.

[0253] The motion state analysis module is used to determine the working state and motion stage of the axial metering vane pump, and to draw a two-dimensional model of the vane-stator kinematic pair.

[0254] The calculation model building module is used to calculate the displacement of the axial fixed displacement vane pump under different motion states and motion stages based on the stator surface equation, and to build a mathematical calculation model for the displacement of the axial fixed displacement vane pump and a calculation model for the instantaneous flow rate and pulsation rate.

[0255] The flow characteristic analysis module is used to combine the displacement mathematical calculation model and the instantaneous flow rate and pulsation rate calculation model to establish the lumped parameter model of the axial fixed displacement vane pump and perform flow characteristic analysis on the axial fixed displacement vane pump.

[0256] The flow characteristic analysis system for the axially metered vane pump disclosed in the above embodiments has modules whose functions correspond to the steps of the flow characteristic analysis method for the axially metered vane pump disclosed in the above embodiments. During implementation, the above embodiments are referred to for operation, and will not be repeated here.

[0257] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for analyzing the flow characteristics of an axially fixed displacement vane pump, characterized in that, include: Construct the stator surface equation and blade surface equation of an axially fixed displacement vane pump; The parameters of the blade surface equation and the stator surface equation are determined, and the three-dimensional model of the blade and the stator surface model are drawn in the three-dimensional modeling software. The blade 3D model is assembled with the stator surface model to obtain the blade-stator kinematic pair; Calculate the volume of the axially fixed displacement vane pump based on the volume parameters of the blade-stator kinematic pair. Determine the working state and blade motion stage of the axial metering vane pump, and draw a two-dimensional model of the blade-stator kinematic pair; The displacement of the axial metering vane pump under different motion states and stages is calculated based on the stator surface equation. A mathematical calculation model for the displacement and a calculation model for the instantaneous flow rate and pulsation rate of the axial metering vane pump are constructed by combining the two-dimensional model. By combining the displacement mathematical calculation model and the instantaneous flow rate and pulsation rate calculation model, a lumped parameter model of the axial fixed displacement vane pump is established, and the flow characteristics of the axial fixed displacement vane pump are analyzed.

2. The method for analyzing the flow characteristics of an axially fixed displacement vane pump according to claim 1, characterized in that, The blade types of the axial metering vane pump include elliptical apex profile, triangular apex profile, triangular dome profile, chamfered apex profile, pointed apex profile, wedge-shaped arc apex profile, single arc apex profile, and arc apex profile; The derivation methods for the blade surface equation of elliptical blades include: Establish a three-dimensional rectangular coordinate system for the blade, and make the blade symmetrical about the x-axis both vertically and horizontally. The standard equation of the ellipse in the rectangular coordinate system is determined as follows: The equation of the ellipse placed in the x=r² section of the rectangular coordinate system is: The formulas for the upper elliptical surface, the middle sector region, and the lower elliptical surface of the blade at the x=r2 section are derived as follows: The coordinates of any point on the blade are ( x , y , z ), leaves in z Viewed from above along the positive axis, it appears as a fan-shaped surface, with the blades occupying an angle of 2°. φ 1. The inner radius of the stator is r 1 The outer radius of the stator is r 2 The angle between any point on the blade and the x-axis is . θ The leaves are x=r 2 The major axis of the ellipse on the cross section is 2 a The minor axis is 2b, and the overall height of the blade is... H The radius of the sector is R .

3. The method for analyzing the flow characteristics of an axially fixed displacement vane pump according to claim 2, characterized in that, The stator curves of the axial metering vane pump include sine curves, constant acceleration-constant deceleration curves, quintic curves, and octet curves. The derivation method of the stator surface equation includes: Equations for the stator helical surface and sector surface are established based on the surface of revolution and the helical surface. Establish a three-dimensional rectangular coordinate system with the origin O on the central axis of the stator. The top view of the stator consists of four curved surfaces: the lower sector surface, the right helical surface, the upper sector surface, and the left helical surface. The surface equation of the lower sector of the stator is calculated as follows: The surface equation of the right-hand helical surface of the stator is calculated as follows: The surface equation of the upper sector of the stator is calculated as follows: The upper sector-shaped surface lies on the plane z=T; The surface equation of the left-hand helical surface of the stator is calculated as follows: Among them, the blade rotation angle α This represents the angle at which the blade rotates on the stator; the upper sector surface... z=T On the plane, the lower sector surface is z=0 On the plane, the angles occupied by the upper and lower sector surfaces are both φ 2. The radius of the inner circle of the stator is r 1 The radius of the outer surface of the stator is r 2 .

4. The method for analyzing the flow characteristics of an axially fixed displacement vane pump according to claim 3, characterized in that, The process of determining the parameters of the blade surface equation and the stator surface equation, and drawing the 3D model of the blade and the stator surface in 3D modeling software, specifically includes: Calculate the major and minor axes of the elliptical blade, and calculate the cross-sectional size of the blade at different positions; Draw a sketch of the blade in 3D modeling software, and draw the cross-sections of the two distal ends of the blade; Connect the two sections using the loft operation to generate a solid, draw the inner and outer circular surfaces of the blade, and use the extrude cut operation to cut out the inner and outer circular surfaces of the blade to obtain the three-dimensional model of the blade. The parameters of the stator surface equation are determined, the stator surface equation is converted into a code language, the key parameters are determined and then entered into the program to obtain the point coordinates of the stator surface, forming a point set of the stator surface; The stator surface point set is imported into the 3D modeling software to generate a stator curve. The stator curve is then subjected to feature stretching and scanning cut graphic processing to obtain a shaped stator surface model.

5. The method for analyzing the flow characteristics of an axially fixed displacement vane pump according to claim 4, characterized in that, The blade 3D model is assembled with the stator surface model to obtain the blade-stator kinematic pair. The specific process includes: The upper and lower stators are set as fixed constraints, the outer surface of the drive shaft is fitted and constrained with the inner surface of the stator, and the drive shaft is set to be rotatable. The two sides of the blade are fitted together with the blade groove of the transmission shaft, and the blade motion constraint is set to obtain the blade-stator motion pair.

6. The method for analyzing the flow characteristics of an axially fixed displacement vane pump according to claim 5, characterized in that, Based on the volume parameters of the blade-stator kinematic pair, the volume of the axially fixed displacement vane pump is calculated. The specific process includes: Based on the volume parameters of the blade-stator kinematic pair and the symmetry of the stator structure, the volume of the axially fixed displacement vane pump is calculated as follows: 。 7. The method for analyzing the flow characteristics of an axially fixed displacement vane pump according to claim 6, characterized in that, The working state and movement stage of the axially displaced vane pump are determined, and a two-dimensional model of the vane-stator kinematic pair is drawn. The specific process includes: According to the blade rotation angle of the axial metering vane pump α During the first stage of motion, the blade rotation angle is (180°-90° / n )≤ α ≤(180°- φ 2 / 2), the blade is on the upper helical surface, and there exists n Number of oil suction chambers and blade pairs n equal, n +1 oil drain chamber; During the second phase of motion, the blade rotation angle is (180°- φ 2 / 2)≤ α ≤(180°+ φ 2 / 2), the blade is located in the fan-shaped planar region, at this time, there exists n One oil suction chamber, n Number of oil discharge chambers and blade pairs n equal; During the third stage of motion, the blade rotation angle is 180°+ φ 2 / 2)≤ α ≤(180°+90° / n The blade is located in the downward spiral region, and there is... n +1 oil suction chamber n Number of oil discharge chambers and blade pairs n equal; The axial metering vane pump rotates one revolution of the vanes through 2n cycles, each cycle including the first motion phase, the second motion phase and the third motion phase; For the blade-stator kinematic pair along the outer circumferential surface of the stator r 2 Unfold and draw a two-dimensional model of the blade-stator kinematic pair.

8. The method for analyzing the flow characteristics of an axially fixed displacement vane pump according to claim 7, characterized in that, The displacement of the axially fixed displacement vane pump under different motion states and stages is calculated based on the stator surface equation. A mathematical calculation model for the displacement and a calculation model for the instantaneous flow rate and pulsation rate of the axially fixed displacement vane pump are constructed. The specific process includes: The rising spiral of the stator is calculated based on the stator surface equation. PQ and descending spiral MN ; During the first phase of motion (180°-90° / n )≤ α ≤(180°- φ 2 / 2), exists n The number of oil suction chambers is equal to the number of blades. n +1 oil drain chamber, calculated by subtracting the total volume of n-1 blades on the upper part of the drive disc from the volume between the drive disc and the stator. V 1~ V n-1 And the volume of the blade on the side of the oil suction chamber n where the plane containing the contact line between the nth blade and the stator is located. V n The displacement of the axially fixed displacement vane pump in the first motion phase is obtained. V Ⅰ ; In the second phase of motion (180°- φ 2 / 2)≤ α ≤(180°+ φ 2 / 2), exists n The number of oil suction chambers is equal to the number of blades. n Each oil discharge chamber has its blades located within the upper fan-shaped area. The volume between the drive disc and the stator is subtracted from the blade volume. V 1~ V n The displacement of the axially fixed displacement vane pump in the second motion phase is obtained. V Ⅱ ; In the third motion phase (180°+) φ 2 / 2)≤ α ≤(180°+90° / n ),exist n +1 oil suction chamber n The number of oil discharge chambers is equal to the number of blades. The blades are located within the lower helical surface region. The volume between the drive disc and the stator is subtracted. n +1 leaf volume V 1~ V n+1 The displacement of the axially fixed displacement vane pump in the third motion stage is obtained. V Ⅲ ; The mathematical model for calculating the displacement of the axially fixed displacement vane pump is as follows: in, n The number of leaf pairs. V max This represents the maximum sealed cavity volume within a volume change cycle. V min The minimum sealed cavity volume value within one volume change cycle; Calculate the instantaneous flow rate of the axial metering vane pump based on the rotational angular velocity and rotational speed of the drive shaft. q in for: in, α The blade rotation angle; Based on the regular variation characteristics of the instantaneous flow rate of the axially fixed displacement vane pump during oil suction and discharge, the flow rate pulsation is calculated as follows: Where, max( q in ) represents the maximum instantaneous flow rate, min( q in () represents the minimum instantaneous flow rate. q t This represents the average theoretical flow rate.

9. The method for analyzing the flow characteristics of an axially fixed displacement vane pump according to claim 8, characterized in that, A lumped parameter model of the axially fixed displacement vane pump is established, and the flow characteristics of the axially fixed displacement vane pump are analyzed. The specific process includes: By integrating the displacement mathematical calculation model and the instantaneous flow rate and pulsation rate calculation model, the lumped parameter model of the axial fixed displacement vane pump is obtained. Based on the lumped parameter model, the influence characteristics of the sector angle, blade occupancy angle, stator inner circle radius, and stator outer circle radius on the displacement and pulsation rate of the axial metering vane pump are analyzed.

10. A flow characteristic analysis system for an axially fixed displacement vane pump, characterized in that, The method for analyzing the flow characteristics of an axially fixed displacement vane pump as described in any one of claims 1 to 9 includes: The surface equation construction module is used to construct the stator surface equation and blade surface equation of an axially fixed displacement vane pump. The 3D model construction module is used to determine the parameters of the blade surface equation and the stator surface equation, and to draw the 3D model of the blade and the stator surface model in the 3D modeling software. The motion model assembly module is used to assemble the three-dimensional model of the blade with the surface model of the stator to obtain the blade-stator motion pair; The pump volume calculation module is used to calculate the volume of the axial metering vane pump based on the volume parameters of the blade-stator kinematic pair. The motion state analysis module is used to determine the working state and motion stage of the axial metering vane pump, and to draw a two-dimensional model of the vane-stator kinematic pair. The calculation model construction module is used to calculate the displacement of the axial fixed displacement vane pump under different motion states and motion stages based on the stator surface equation, and to construct the displacement mathematical calculation model and instantaneous flow rate and pulsation rate calculation model of the axial fixed displacement vane pump in combination with the two-dimensional model. The flow characteristic analysis module is used to combine the displacement mathematical calculation model and the instantaneous flow rate and pulsation rate calculation model to establish the lumped parameter model of the axial quantitative vane pump and perform flow characteristic analysis on the axial quantitative vane pump.

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