Cylinder vibration displacement prediction method for aviation axial piston pump based on dynamic simulation

Abstract

The application provides a cylinder vibration displacement prediction method for an aviation axial plunger pump, and belongs to the technical field of simulation calculation. The aviation axial plunger pump is the core of an aviation hydraulic system, and the core component, the cylinder, is prone to many vibration problems in the process of high-speed rotation. The aviation axial plunger pump cylinder vibration displacement prediction method based on dynamic simulation provided by the application starts from the multi-rigid-body dynamic simulation model of the axial plunger pump, introduces the system simulation result to increase the accuracy, performs flexible treatment on the cylinder through modal analysis of finite element simulation, and establishes a rigid-flexible coupling simulation model. Finally, the load transmitted to the cylinder by the plunger is extracted, the model is reasonably simplified, the bearing and sensor simplified models are added, the model is further improved, the vibration displacement of the cylinder is accurately predicted, and a basis is provided for subsequent design and reliability and stability research of the aviation axial plunger pump.

Description

Technical Field

[0001] This invention belongs to the field of simulation calculation technology, and relates to a method for predicting cylinder vibration displacement of an aviation axial piston pump, and particularly to a reciprocating seal test device and verification method for aviation hydraulic actuators. Background Technology

[0002] Hydraulic systems are crucial electromechanical systems in modern aircraft. Braking, engine thrust reverser, and flight control all rely on hydraulic transmission and servo control technology. The aviation axial piston pump converts the mechanical energy output from the engine or motor into hydraulic energy, making it a core component of the aviation hydraulic system. During operation, the spindle rotates under the drive of the engine or motor, which in turn rotates the cylinder block via splines, causing the pistons in the cylinder bore to rotate as well. Simultaneously, the pistons reciprocate linearly under the combined action of the swashplate and chuck, continuously changing the volume of the piston chamber to achieve the oil suction and discharge function. During the oil suction and discharge process, the switching between high and low pressure oil, as well as imbalances and misalignments in the rotating components, cause significant vibrations and pose a risk of instability. In the design and research of aerospace axial piston pumps, the measurement and calculation of vibration signals are mostly carried out through the casing. However, the force transmission path of the piston pump is relatively complex, and the vibration signal of the casing is difficult to directly reflect the vibration of the internal rotating components. Furthermore, the experimental measurement of the vibration signal of the rotating components requires modifications to the piston pump, such as opening holes in the casing, which is costly and has certain limitations.

[0003] The cylinder block, connecting the spindle and piston within the rotating assembly, is the most crucial component of the piston pump. Accurate prediction of the cylinder block's vibration signals through simulation calculations allows for a more precise assessment of the overall vibration of the piston pump, providing a basis for subsequent design and anti-tipping stability studies of aerospace axial piston pumps. Currently, there is no simulation calculation method for the vibration displacement of the aerospace axial piston pump cylinder block identical to that of this invention. Summary of the Invention

[0004] This invention addresses the technical problem of the current lack of simulation calculation methods for the vibration displacement of aerospace axial piston pump cylinders. The purpose of this invention is to provide a method for predicting the vibration displacement of aerospace axial piston pump cylinders based on dynamic simulation. This method involves performing multi-rigid-body dynamic analysis on the rotating assembly, system simulation analysis on the pressure regulating system, and modal simulation analysis on the cylinder. Finally, based on Motion calculation and analysis software, the rigid-flexible coupling model of the rotating assembly is simulated and calculated to achieve accurate prediction of the cylinder vibration displacement, providing a basis for subsequent design and research.

[0005] Technical solution:

[0006] A method for predicting the vibration displacement of an aerospace axial piston pump cylinder based on dynamic simulation is proposed. This method involves performing multi-rigid-body dynamic analysis on the rotating component, system simulation analysis on the pressure regulating system, modal simulation analysis on the cylinder, and simulation calculation on the rigid-flexible coupling model of the rotating component. This method achieves accurate prediction of the cylinder vibration displacement and provides a basis for subsequent design and research.

[0007] Furthermore, simulation calculations were performed on the rigid-flexible coupling model of the rotating component using Motion calculation and analysis software.

[0008] Furthermore, the method specifically includes the following steps:

[0009] Step 1: Establish the geometric model of the aerospace axial piston pump and extract the rotating components;

[0010] Step 2: Add kinematic pairs based on the kinematic relationship between the rotating components in Step 1; add loads to the key components in the rotating components according to the force conditions of the key components; add a drive to the main shaft in the rotating components according to the actual working conditions; and establish a multi-rigid-body dynamics simulation model of the rotating components based on the Motion calculation and analysis software.

[0011] Step 3: Based on the Amesim calculation software, establish a simulation model of the plunger pump pressure regulating system, and calculate the hydraulic pressure load in the plunger chamber through the simulation model of the plunger pump pressure regulating system.

[0012] Step 4: Apply the plunger chamber hydraulic pressure load calculated in Step 3 to the simulation model in Step 2, and establish a joint simulation model of the rotating component based on Motion calculation and analysis software and Amesim calculation software.

[0013] Step 5: Based on the simulation model in Step 4 and the modal analysis results of the cylinder, establish a rigid-flexible coupling simulation model of the rotating component, and analyze and calculate the vibration displacement of the cylinder.

[0014] Furthermore, the key components in step two include the plunger slipper assembly, cylinder block, and distributor plate.

[0015] Furthermore, in step three, a simulation model of the piston pump pressure regulation system is established by combining the working principle and pressure regulation principle of the aviation axial piston pump.

[0016] Furthermore, step five specifically includes the following steps:

[0017] Step 5.1 Establish a rigid-flexible coupling simulation model of the rotating component;

[0018] Step 5.2 Simplify and improve the rigid-flexible coupling simulation model of the rotating component;

[0019] Step 5.3 Using the simplified and improved rigid-flexible coupling simulation model of the rotating component from Step 5.2, predict the cylinder vibration displacement under a specified working condition.

[0020] Furthermore, step 5.1 specifically involves: determining the actual position of the cylinder block and the spline connection of the main shaft based on the engineering drawing, determining the connection point based on the kinematic pair in the multi-rigid-body dynamics simulation model, and finally performing modal analysis on the cylinder block based on finite element software, and importing the modal analysis results into the multi-rigid-body dynamics simulation model to realize the flexibility of the cylinder block and establish a rigid-flexible coupling simulation model of the rotating component.

[0021] Furthermore, step 5.2 specifically involves: using the simulation model from step four to calculate the load transmitted from the plunger to the cylinder block, thereby simplifying the complex plunger slipper assembly; considering that the spindle bearing has a significant impact on the vibration displacement of the cylinder block, a simplified model of the bearing is added to the rigid-flexible coupling simulation model of the rotating assembly obtained in step 5.1. At the same time, in order to better characterize the vibration displacement of the cylinder block, a simplified model of the sensor is added to the rigid-flexible coupling simulation model of the rotating assembly as a measurement reference.

[0022] Furthermore, in step 5.2, a small spring is added to the end face of the cylinder block to simulate the supporting effect of the oil in the actual distribution pair.

[0023] Beneficial effects

[0024] This invention simplifies and processes the rotating component model of an aerospace axial piston pump by establishing a multi-dimensional simulation model, enabling accurate prediction of the vibration displacement of the aerospace piston pump cylinder. This allows for more accurate analysis of the piston pump's vibration, providing a basis for subsequent design and reliability and stability studies of aerospace axial piston pumps. Attached Figure Description

[0025] Figure 1 This is a flowchart of the workflow of the method of the present invention.

[0026] Figure 2 It is a multi-rigid-body dynamics simulation model of rotating components built using Motion.

[0027] Figure 3 It is a simulation model of a plunger pump pressure regulating system built using Amesim.

[0028] Figure 4 It is a simplified and improved simulation model of the rigid-flexible coupling of the rotating component.

[0029] Figure 5 It is the time-domain response curve of cylinder vibration displacement calculated by this method under rated operating conditions. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only some embodiments of the present invention, and 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.

[0031] The present invention will now be described in further detail with reference to the accompanying drawings and specific examples:

[0032] One embodiment of the present invention is as follows:

[0033] The method for predicting the vibration displacement of the cylinder block of an aerospace axial piston pump based on dynamic simulation involves multi-rigid-body dynamic analysis of the rotating component, system simulation analysis of the pressure regulating system, modal simulation analysis of the cylinder block, and simulation calculation of the rigid-flexible coupling model of the rotating component. This method achieves accurate prediction of the cylinder block vibration displacement, providing a basis for subsequent design and research. Specifically, the simulation calculation of the rigid-flexible coupling model of the rotating component is based on the Motion calculation and analysis software.

[0034] In this embodiment, the method specifically includes the following steps:

[0035] Step 1: Establish the geometric model of the aerospace axial piston pump and extract the rotating components;

[0036] Step 2: Add kinematic pairs based on the kinematic relationships between the rotating components in Step 1; add loads to the key components in the rotating components according to the force conditions of the key components; add a drive to the main shaft in the rotating components according to the actual working conditions; and establish a multi-rigid-body dynamics simulation model of the rotating components based on the Motion calculation and analysis software; the key components include the plunger slipper assembly, cylinder block, and distributor plate.

[0037] Step 3: Based on the Amesim calculation software, establish a simulation model of the plunger pump pressure regulation system, and calculate the hydraulic pressure load in the plunger chamber through the plunger pump pressure regulation system simulation model; in Step 3, combine the working principle and pressure regulation principle of the aerospace axial plunger pump to establish a simulation model of the plunger pump pressure regulation system.

[0038] Step 4: Apply the plunger chamber hydraulic pressure load calculated in Step 3 to the simulation model in Step 2, and establish a joint simulation model of the rotating component based on Motion calculation and analysis software and Amesim calculation software.

[0039] Step 5: Based on the simulation model in Step 4 and the modal analysis results of the cylinder, establish a rigid-flexible coupling simulation model of the rotating component, and analyze and calculate the vibration displacement of the cylinder.

[0040] Specifically, the following steps are included:

[0041] Step 5.1 Establish a rigid-flexible coupling simulation model of the rotating component: Determine the actual position of the cylinder and the spline connection of the main shaft according to the engineering drawing, determine the connection point according to the kinematic pair in the multi-rigid-body dynamics simulation model, and finally perform modal analysis on the cylinder based on finite element software, and import the modal analysis results into the multi-rigid-body dynamics simulation model to realize the flexibility of the cylinder and establish a rigid-flexible coupling simulation model of the rotating component.

[0042] Step 5.2 Simplify and improve the rigid-flexible coupling simulation model of the rotating component: Calculate the load transmitted from the plunger to the cylinder using the simulation model from Step 4, thereby simplifying the complex plunger slipper assembly; considering that the spindle bearing has a significant impact on the vibration displacement of the cylinder, a simplified model of the bearing is added to the rigid-flexible coupling simulation model of the rotating component obtained in Step 5.1. At the same time, in order to better characterize the vibration displacement of the cylinder, a simplified model of the sensor is added to the rigid-flexible coupling simulation model of the rotating component as a measurement reference; in Step 5.2, a small spring is added to the end face of the cylinder to simulate the supporting effect of the oil in the actual distribution pair.

[0043] Step 5.3 Using the simplified and improved rigid-flexible coupling simulation model of the rotating component from Step 5.2, predict the cylinder vibration displacement under a specified working condition.

[0044] The second embodiment of the present invention is:

[0045] This invention provides a method for predicting the vibration displacement of an aerospace axial piston pump cylinder based on dynamic simulation. To make the objectives and concepts of this invention clearer and more explicit, examples are provided for further detailed explanation. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0046] The method of this invention simplifies and processes the rotating component model of an aerospace axial piston pump by establishing a multi-dimensional simulation model, simulating the actual working environment of the piston pump, and accurately calculating the vibration displacement of the cylinder block. The specific implementation steps are as follows:

[0047] (1) Pre-modeling assumptions: First, some assumptions and simplifications are made for each component of the aerospace axial piston pump. It is assumed that the piston pump cylinder is a flexible body, and the main shaft, piston, slipper, and swashplate in the piston pump are all rigid bodies, ignoring their elastic changes during operation; the constraints in the physical prototype are all treated as ideal constraints; the springs and dampers in the physical prototype are modeled as linear springs and dampers in the virtual prototype, and the damping coefficient of the spring and the elastic coefficient of the damper are ignored.

[0048] (2) Establishing a multi-rigid-body dynamic model of the rotating assembly: First, in Motion, the geometric model of the piston pump rotating assembly is transformed into a moving body by defining the center of mass, inertial coordinate system, mass, and polar moment of inertia; then, by specifying the origin and coordinate system, the kinematic relationships between the moving bodies are determined using kinematic pairs such as spherical joints and revolute joints; subsequently, based on the force analysis, loads are applied to key components, mainly including the piston chamber fluid pressure and the frictional force between the piston and the cylinder block, and the theoretical calculation formulas are as follows:

[0049]

[0050] F f =f(F1+F2)

[0051] In the formula F z d is the plunger cavity hydraulic pressure, d is the plunger diameter, and P is the plunger diameter. z F is the pressure in the plunger cavity. f F represents the frictional force between the plunger and the cylinder block, f is the friction coefficient affected by the properties of the mating materials, and F1 and F2 are the contact stresses between the plunger and the cylinder bore. Finally, a drive at a rated speed is applied to the spindle end face to simulate the driving action of an engine or electric motor.

[0052] After establishing the multi-rigid-body dynamics model of the rotating component, the force conditions on the bottom surface of the slipper and the velocity and displacement of the plunger are extracted and compared with the theoretical formulas. Based on this, the model is adjusted so that it can better reflect the theoretical analysis. The theoretical formulas to be compared are as follows:

[0053]

[0054] In the formula F N F represents the support reaction force of the swashplate. g F represents the inertial force of the plunger's axial motion. x This represents the centrifugal reaction force generated by centripetal acceleration. ω represents the swashplate tilt angle, k is a structural parameter; l represents the piston displacement, r is the radius of the piston distribution circle, μ is the cylinder rotation angle; v represents the piston velocity, and ω represents the cylinder rotation angular velocity.

[0055] (3) Establish a simulation model of the plunger pump pressure regulating system: Ignore the influence of temperature on the plunger pump characteristics and assume that the leakage between rotating components is laminar leakage. Based on the working principle and pressure regulating principle of the plunger pump, a simulation model of the plunger pump pressure regulating system is established in Amesim software using different libraries and components. Adjust the valve opening to make the load flow rate match the demand under rated operating conditions, and extract the plunger chamber fluid pressure at this time.

[0056] (4) Replace the hydraulic pressure of the plunger chamber obtained by theoretical calculation in (2) with the load extracted in (3) to establish a joint simulation model of the rotating component, and extract the load transmitted from the plunger to the cylinder based on this model.

[0057] (5) Calculation of cylinder vibration displacement:

[0058] a. Determine the actual connection position between the cylinder block and the main spindle spline according to the engineering drawing, and determine the relevant connection points of the cylinder block according to the kinematic pairs in the multi-rigid-body dynamics simulation model. Based on the finite element software, add far-end displacement constraints at the spline position of the cylinder block, mainly constraining the translation and rotation of the cylinder block in the axial direction; at the same time, add mass points with a mass of 0.001g at the connection points with other components, so that the cylinder block mesh generates RBE2 mesh at the corresponding positions. Analyze and calculate the modal characteristics of the cylinder block, and import the results into (5)a. model to establish a rigid-flexible coupling simulation model of the rotating component.

[0059] b. Replace the cumbersome plunger slipper assembly with the load calculated in (4). Add a simplified model of the spindle bearing and simulate its radial stiffness with a spring, calculated as follows:

[0060] R rt =0.118×10 4 (D q F r Z 2 cos 5 β) 1 / 3

[0061]

[0062] In the formula, R rt F represents the radial stiffness of a single-row radial ball bearing. r Z represents the radial load of the bearing, Z represents the number of rollers in the bearing, β represents the contact angle of the bearing, and D represents the radial load of the bearing. q R represents the diameter of the ball in a radial ball bearing. rr L represents the radial stiffness of a single-row cylindrical roller bearing. c This represents the cylindrical length of the cylindrical roller bearing. A simplified sensor model is incorporated as a measurement reference, with the initial distance between the sensor end face and the cylinder block set to 0.7 mm. A small spring is added to the cylinder block end face to simulate the supporting effect of the oil in the distribution pair.

[0063] c. The cylinder vibration displacement of the aerospace axial piston pump under rated operating conditions can be obtained through simulation calculation.

[0064] The third embodiment of the present invention

[0065] like Figures 2 to 5 As shown, the specific implementation process of the method for predicting the vibration displacement of the cylinder block of an aerospace axial piston pump based on dynamic simulation in this invention is as follows:

[0066] Step 1: Establish a multi-rigid-body dynamics simulation model for the rotating component, such as... Figure 2 As shown;

[0067] Step 2: Extract the calculation results of the multi-rigid-body dynamics simulation model and compare them with the theoretical calculation results. Adjust the model based on the comparison results.

[0068] Step 3: Establish a simulation model of the plunger pump pressure regulating system, such as Figure 3 As shown;

[0069] Step 4: Introduce the plunger chamber hydraulic pressure calculated in the system simulation model into the multi-rigid-body dynamics simulation model, and extract the load transmitted from the plunger to the cylinder at this time;

[0070] Step 5: Perform modal analysis on the cylinder block using finite element software, and import the calculation results into the model from Step 4 to establish a rigid-flexible coupling simulation model of the rotating component;

[0071] Step 6: Simplify the plunger slipper assembly based on the calculation results of Step 4; add a simplified bearing model and use a spring to simulate its radial stiffness; add a simplified sensor model, setting its initial distance from the cylinder block to 0.7mm; add a small end face spring to simulate the supporting effect of the oil in the distribution pair; complete the simplification and improvement of the rigid-flexible coupling simulation model.

[0072] Step 7: Predict the cylinder block vibration displacement through simulation calculation.

[0073] This patent has many specific applications. The above description is only a preferred embodiment of this patent and does not limit the implementation method and scope of protection of this patent. For those skilled in the art, the solutions obtained by making equivalent substitutions and obvious changes under the premise of the principle of this patent should be included in the scope of protection of the patent.

Claims

1. A method for predicting the vibration displacement of an aerospace axial piston pump cylinder based on dynamic simulation, characterized in that, The method achieves accurate prediction of cylinder vibration displacement by performing multi-rigid-body dynamics analysis on the rotating component, system simulation analysis on the pressure regulating system, modal simulation analysis on the cylinder, and simulation calculation on the rigid-flexible coupling model of the rotating component, providing a basis for subsequent design and research.

2. The method for predicting the vibration displacement of an aerospace axial piston pump cylinder based on dynamic simulation according to claim 1, characterized in that, Simulation calculations were performed on the rigid-flexible coupling model of the rotating component using Motion calculation and analysis software.

3. The method for predicting the vibration displacement of an aerospace axial piston pump cylinder based on dynamic simulation according to claim 2, characterized in that, The method specifically includes the following steps: Step 1: Establish the geometric model of the aerospace axial piston pump and extract the rotating components; Step 2: Add kinematic pairs based on the kinematic relationship between the rotating components in Step 1; add loads to the key components in the rotating components according to the force conditions of the key components; add a drive to the main shaft in the rotating components according to the actual working conditions; and establish a multi-rigid-body dynamics simulation model of the rotating components based on the Motion calculation and analysis software. Step 3: Based on the Amesim calculation software, establish a simulation model of the plunger pump pressure regulating system, and calculate the hydraulic pressure load in the plunger chamber through the simulation model of the plunger pump pressure regulating system. Step 4: Apply the plunger chamber hydraulic pressure load calculated in Step 3 to the simulation model in Step 2, and establish a joint simulation model of the rotating component based on Motion calculation and analysis software and Amesim calculation software. Step 5: Based on the simulation model in Step 4 and the modal analysis results of the cylinder, establish a rigid-flexible coupling simulation model of the rotating component, and analyze and calculate the vibration displacement of the cylinder.

4. The method for predicting the vibration displacement of an aerospace axial piston pump cylinder based on dynamic simulation according to claim 2, characterized in that, Key components in step two include the plunger slipper assembly, cylinder block, and distributor plate.

5. The method for predicting the vibration displacement of an aerospace axial piston pump cylinder based on dynamic simulation according to claim 3, characterized in that, In step three, a simulation model of the piston pump pressure regulation system is established by combining the working principle and pressure regulation principle of the aviation axial piston pump.

6. The method for predicting the vibration displacement of an aerospace axial piston pump cylinder based on dynamic simulation according to claim 3, characterized in that, Step five specifically includes the following steps: Step 5.1 Establish a rigid-flexible coupling simulation model of the rotating component; Step 5.2 Simplify and improve the rigid-flexible coupling simulation model of the rotating component; Step 5.3 Using the simplified and improved rigid-flexible coupling simulation model of the rotating component from Step 5.2, predict the cylinder vibration displacement under a specified working condition.

7. The method for predicting the vibration displacement of an aerospace axial piston pump cylinder based on dynamic simulation according to claim 6, characterized in that, Step 5.1 specifically involves: determining the actual position of the cylinder block and the spline connection of the main shaft based on the engineering drawings, determining the connection point based on the kinematic pairs in the multi-rigid-body dynamics simulation model, and finally performing modal analysis on the cylinder block based on finite element software, and importing the modal analysis results into the multi-rigid-body dynamics simulation model to realize the flexibility of the cylinder block and establish a rigid-flexible coupling simulation model of the rotating component.

8. The method for predicting the vibration displacement of an aerospace axial piston pump cylinder based on dynamic simulation according to claim 7, characterized in that, Step 5.2 specifically involves: using the simulation model from step four to calculate the load transmitted from the plunger to the cylinder, thereby simplifying the complex plunger slipper assembly; considering that the spindle bearing has a significant impact on the vibration displacement of the cylinder, a simplified model of the bearing is added to the rigid-flexible coupling simulation model of the rotating assembly obtained in step 5.

1. At the same time, in order to better characterize the vibration displacement of the cylinder, a simplified model of the sensor is added to the rigid-flexible coupling simulation model of the rotating assembly as a measurement reference.

9. The method for predicting the vibration displacement of an aerospace axial piston pump cylinder based on dynamic simulation according to claim 8, characterized in that, In step 5.2, a small spring is added to the end face of the cylinder block to simulate the supporting effect of the oil in the actual distribution pair.

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