A method for testing a dual-motion-degree-of-freedom piston pump

Abstract

The application provides a kind of double motion degree of freedom piston pump vibration test method, comprising: S1, the system modal shape of double motion degree of freedom piston pump is obtained by finite element dynamics characteristic analysis, and vibration acceleration test point position is determined according to the system modal shape of double motion degree of freedom piston pump;S2, install and arrange high temperature vibration signal test system;S3, respectively from radial and axial excitation double motion degree of freedom piston pump test machine, open test machine to run at rated operating condition, utilize acceleration sensor to test machine radial and axial time domain, data acquisition system vibration signal acquisition and transmission to data analysis system;S4, data analysis system according to vibration signal carries out the modal parameter identification and vibration characteristic analysis of pump system, obtains the modal shape of each order of test machine, determines the natural frequency of each order of system, obtains vibration characteristic parameter under high temperature condition.The application effectively improves test efficiency and data accuracy, ensures high temperature state system stable operation.

Description

Technical Field

[0001] This invention relates to the field of fluid machinery technology, and in particular to a vibration testing method for a piston pump with two degrees of freedom of motion. Background Technology

[0002] A pump is an energy conversion device that converts mechanical energy into fluid pressure energy, typically used to output high-pressure fluids. Traditional pumps, such as piston, vane, gear, and screw pumps, rely primarily on sliding friction in their mechanical structure during operation, resulting in significant frictional energy loss. Furthermore, their components have complex shapes and high manufacturing costs.

[0003] The dual-degree-of-freedom piston pump integrates the shaft and piston into a single design, utilizing the piston's "circumferential rotation + axial reciprocating" dual-degree-of-freedom motion principle to achieve continuous oil suction and discharge, eliminating the need for the distributor plate structure in traditional plunger pumps. Simultaneously, a symmetrical cam roller structure replaces the sliding shoe swashplate structure, transforming the original sliding friction pair into rolling friction. Furthermore, the symmetrical force-bearing structure ensures that the piston experiences no radial force, eliminating the two friction pairs between the piston and cylinder, and between the cylinder and distributor plate. This results in higher pump efficiency and overcomes the limitations imposed on pump performance by sliding friction pairs.

[0004] Due to their unique operating principles and structure, the performance characteristics of dual-degree-of-freedom piston pumps differ somewhat from those of traditional pumps. Accurate acquisition and analysis of performance parameters such as flow rate, pressure, and vibration characteristics require customized experimental analysis methods and systems. Existing experimental systems exhibit incompatibility in high-temperature and high-speed performance testing, and vibration testing methods are unable to accurately acquire and analyze the vibration characteristics of dual-degree-of-freedom piston pumps, thus impacting performance characteristic analysis and modal analysis. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art.

[0006] According to one aspect of the present invention, a vibration testing method for a piston pump with two degrees of freedom of motion is provided, the vibration testing method for a piston pump with two degrees of freedom of motion includes:

[0007] S1. The system mode shape of the dual-degree-of-freedom piston pump is obtained through finite element dynamic characteristic analysis. The vibration acceleration test points are determined based on the system mode shape of the dual-degree-of-freedom piston pump.

[0008] S2, Install and deploy the high-temperature vibration signal testing system;

[0009] S3, respectively, from the radial and axial excitation double motion freedom piston pump prototype to be tested, open the prototype to be tested to run in the rated operating condition, use the acceleration sensor to test the prototype to be tested in the time domain in the radial and axial directions, the data acquisition system collects the vibration signal and transmits it to the data analysis system;

[0010] S4, the data analysis system identifies the modal parameters of the pump system and analyzes the vibration characteristics according to the vibration signal, obtains the modal shapes of each order of the prototype to be tested, determines the natural frequency of each order of the system, and obtains the vibration characteristic parameters under the high-temperature working condition.

[0011] Further, in S1, the finite element dynamics characteristic analysis specifically includes: establishing a finite element analysis model of the double motion freedom piston pump; confirming the technical state of the prototype to be tested, taking the working speed as the analysis input condition, completing the system dynamics characteristic analysis, and obtaining the modal shapes of each order of the system.

[0012] Further, the finite element analysis is realized by ANSYS or ABAQUS.

[0013] Further, S2 specifically includes: installing the prototype to be tested to the prototype installation platform, installing the test loading system, the medium temperature control and protection system, the medium circulating system, the data acquisition system, the data analysis system, the electrical control system and the upper computer interaction system; the vibration acceleration sensor is installed to the vibration acceleration test point, and the vibration acceleration sensor interacts with the data acquisition system and the data analysis system through the data acquisition system.

[0014] Further, in S3, the force hammer is used to excite the prototype to be tested in the radial and axial directions.

[0015] Further, in S4, the DASP vibration analysis software is used to process the mean value and the fast Fourier transform of the collected vibration signal, obtain the time domain characteristic and the frequency domain characteristic curve, identify the modal parameters of the pump system, and obtain the modal shapes of each order.

[0016] Further, after obtaining the modal shapes of each order of the prototype to be tested, the double motion freedom piston pump vibration test method further includes: correcting the system modal shapes obtained by the finite element dynamics characteristic analysis simulation in S1 according to the modal shapes of each order of the prototype to be tested, and adjusting the vibration acceleration test point.

[0017] According to another aspect of the present application, a double motion freedom piston pump vibration test system is provided, which uses the double motion freedom piston pump vibration test method as described above to test the double motion freedom piston pump vibration.

[0018] Further, the double-motion-freedom piston pump vibration test system comprises a prototype mounting platform, a vibration acceleration sensor, a test loading system, a medium temperature control and protection system, a medium circulation system, a data acquisition system, a data analysis system, an electrical control system and an upper computer interaction system; the prototype mounting platform is used for mounting a to-be-tested prototype; the vibration acceleration sensor is mounted to a vibration acceleration test point; the test loading system is used for respectively exciting the to-be-tested prototype from a radial direction and an axial direction; the medium temperature control and protection system is used for adjusting and setting an environmental temperature of the to-be-tested prototype, and the medium circulation system is used for realizing circulation control of the temperature control medium; the data acquisition system acquires vibration signals obtained by the vibration acceleration sensor and transmits the vibration signals to the data analysis system, and the data analysis system realizes data interaction with the outside world through the upper computer interaction system; and the electrical control system is used for electrical control of the vibration test system.

[0019] The technical scheme of the application provides a double-motion-freedom piston pump vibration test method, which completes double-motion-freedom piston pump vibration test through steps of finite element modal analysis, vibration acceleration test point arrangement, to-be-tested prototype excitation test, vibration parameter identification analysis and the like, can effectively identify system modal characteristic parameters of the double-motion-freedom piston pump, obtains vibration characteristics of the to-be-tested prototype under high-temperature working conditions through a test method, effectively improves test efficiency and data accuracy, and ensures stable operation of the high-temperature state system. Compared with the prior art, the technical scheme of the application can solve the technical problem that the vibration test method in the prior art cannot accurately and effectively test the double-motion-freedom piston pump. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings, which constitute a part of the specification, illustrate embodiments of the application and serve to explain the principles of the application. It is apparent that the accompanying drawings are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of the accompanying drawings.

[0021] Figure 1 A flowchart of a double-motion-freedom piston pump vibration test method provided by a specific embodiment of the application is shown;

[0022] Figure 2 A time-domain analysis result schematic diagram provided by a specific embodiment of the application is shown;

[0023] Figure 3 A frequency spectrum analysis result schematic diagram provided by a specific embodiment of the application is shown. DETAILED DESCRIPTION

[0024] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other in the case of no conflict. The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The description of the at least one example embodiment is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0025] It should be noted that the terms used herein are only intended to describe specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in the specification, there is a reference to the presence of a feature, step, operation, device, component and / or combinations thereof.

[0026] Unless specifically stated otherwise, the relative arrangement of components and steps, numerical expressions, and numerical values set forth in the various embodiments described herein are not limiting. It should be understood that the various parts shown in the drawings are not necessarily drawn to scale in proportion. Techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered as part of the specification where appropriate. In all examples shown and discussed herein, any specific value should be interpreted as merely exemplary, and not as a limitation. Therefore, other examples of the exemplary embodiments can have different values.

[0027] As Figure 1 shown, according to the specific embodiments of the present application, a double-motion-degree-of-freedom piston pump vibration test method is provided, which comprises:

[0028] S1, obtaining the system modal shape of the double-motion-degree-of-freedom piston pump through finite element dynamics characteristic analysis, and determining the vibration acceleration test point according to the system modal shape of the double-motion-degree-of-freedom piston pump;

[0029] S2, installing and arranging a high-temperature vibration signal test system;

[0030] S3, exciting the double-motion-degree-of-freedom piston pump to be tested from the radial and axial directions respectively, starting the to-be-tested sample machine to run under the rated working condition, using an acceleration sensor to perform time-domain test on the to-be-tested sample machine in the radial and axial directions, using a data acquisition system to collect vibration signals and transmit them to a data analysis system;

[0031] S4, the data analysis system performs modal parameter identification and vibration characteristic analysis of the pump system according to the vibration signal, obtains modal shapes of each order of the to-be-tested prototype, determines natural frequencies of each order of the system, and obtains vibration characteristic parameters under a high-temperature working condition.

[0032] By applying the configuration mode, a double-motion-degree-of-freedom piston pump vibration testing method is provided, which completes double-motion-degree-of-freedom piston pump vibration testing through steps such as finite element modal analysis, vibration acceleration test point arrangement, to-be-tested prototype excitation testing, and vibration parameter identification analysis, can effectively identify system modal characteristic parameters of the double-motion-degree-of-freedom piston pump, obtains vibration characteristics of the to-be-tested prototype under a high-temperature working condition through a test means, effectively improves testing efficiency and data accuracy, and ensures stable operation of the system under a high-temperature state.

[0033] Further, in the present application, in order to realize the double-motion-degree-of-freedom piston pump vibration testing method, first, the system modal shape of the double-motion-degree-of-freedom piston pump is obtained through finite element dynamics characteristic analysis, and the vibration acceleration test point position is determined according to the system modal shape of the double-motion-degree-of-freedom piston pump.

[0034] Before performing vibration characteristic testing, the present application first establishes a finite element analysis model of the double-motion-degree-of-freedom piston pump, confirms the technical state of the to-be-tested prototype, takes the working speed as an analysis input condition, completes system dynamics characteristic analysis, and obtains system modal shapes of each order. The present application takes a part with a larger amplitude on the system modal shape of the double-motion-degree-of-freedom piston pump as a vibration acceleration test point arrangement point position, and ensures that the test point position is far away from a vibration interference source.

[0035] As a specific embodiment of the present application, finite element analysis can be realized through ANSYS or ABAQUS, dynamics characteristics are preliminarily determined, the vibration acceleration test point position is set at a part with a larger vibration displacement or a key node as much as possible, the test point position is made far away from a vibration interference source, and the number of test point positions is preferably more than 2.

[0036] Further, in the present application, after the vibration acceleration test point position is determined, a vibration signal testing system is installed and arranged.

[0037] As a specific embodiment of the present application, the to-be-tested prototype is installed to a prototype installation platform, a test loading system, a medium temperature control and protection system, a medium circulation system, a data acquisition system, a data analysis system, an electrical control system, and an upper computer interaction system are installed, a vibration acceleration sensor is installed to the vibration acceleration test point position, the vibration acceleration sensor performs data interaction with the data acquisition system and the data analysis system through the data acquisition system.

[0038] Among them, the data acquisition system can realize the collection of flow, pressure, rotating speed, torque and vibration data; the medium temperature control and protection system can control the test sample machine to be in high temperature working condition or normal temperature working condition.

[0039] Further, in the present application, after the installation and arrangement of the vibration signal test system are completed, the test sample machine is excited from the radial and axial directions respectively, the test sample machine is started to operate under the rated working condition, the acceleration sensor is used to test the radial and axial time domain of the test sample machine, the vibration signal is collected by the data acquisition system and transmitted to the data analysis system.

[0040] As a specific embodiment of the present application, a force hammer can be used to excite the test sample machine from the radial and axial directions respectively. In order to avoid mechanical damage to the test sample machine caused by the force hammer, the force hammer can be an elastic force hammer. The signals collected by the data acquisition system under different working conditions and excitation modes can be transmitted to the rear-end data analysis system through the transmission line.

[0041] Further, in the present application, after the vibration signal is collected, the data analysis system performs modal parameter identification and vibration characteristic analysis of the pump system according to the vibration signal, obtains the modal shape of each order of the test sample machine, determines the natural frequency of each order of the system, and obtains the vibration characteristic parameters under high temperature working condition.

[0042] As a specific embodiment of the present application, the vibration analysis software such as DASP can be used to process the collected vibration signal in a series of ways such as mean value and fast Fourier transform, to obtain the time domain characteristic and frequency domain characteristic curves, identify the modal parameters of the pump system, and obtain the modal shape of each order.

[0043] In addition, in the present application, after the modal shape of each order of the test sample machine is obtained, the double-motion-freedom piston pump vibration test method further comprises: correcting the system modal shape obtained by the finite element dynamics characteristic analysis simulation in S1 according to the modal shape of each order of the test sample machine, and adjusting the vibration acceleration test point position, to further improve the test precision.

[0044] The double-motion-freedom piston pump vibration test method of the present application completes the vibration test of the double-motion-freedom piston pump through the steps of finite element modal analysis, vibration acceleration test point arrangement, force hammer excitation test, and vibration parameter identification analysis, can effectively identify the modal characteristic parameters of the system, obtains the vibration characteristics of the test sample machine under high temperature working condition and the like through experimental means, effectively improves the test efficiency and data accuracy, and ensures the stable operation of the high temperature state system.

[0045] According to another aspect of the present application, a double-motion-freedom piston pump vibration test system is provided, which uses the double-motion-freedom piston pump vibration test method as described above to perform the double-motion-freedom piston pump vibration test.

[0046] The vibration testing system for a dual-degree-of-freedom piston pump includes: a prototype mounting platform, a vibration acceleration sensor, a test loading system, a medium temperature control and protection system, a medium circulation system, a data acquisition system, a data analysis system, an electrical control system, and a host computer interaction system. The prototype mounting platform is used to mount the prototype under test; the vibration acceleration sensor is installed at the vibration acceleration test point; the test loading system is used to excite the prototype under test radially and axially; the medium temperature control and protection system is used to adjust and set the ambient temperature of the prototype under test, and the medium circulation system is used to achieve temperature-controlled medium circulation control; the data acquisition system collects vibration signals from the vibration acceleration sensor and transmits them to the data analysis system, which interacts with the outside world via the host computer interaction system; the electrical control system is used for the electrical control of the vibration testing system.

[0047] The dual-degree-of-freedom piston pump vibration testing system of the present invention can meet the testing requirements of high-speed performance testing, high-temperature performance testing and vibration characteristic testing of the prototype under test, and accurately obtain the performance test data of the prototype under test under various working conditions.

[0048] To gain a further understanding of the present invention, the following description is provided in conjunction with... Figures 1 to 3 The vibration testing method for a two-degree-of-freedom piston pump of the present invention is described in detail.

[0049] The test equipment and its basic requirements required in this specific embodiment are shown in Table 1.

[0050] Table 1 Test Equipment Models

[0051]

[0052] like Figures 1 to 3 As shown in the figure, a vibration testing method for a piston pump with two degrees of freedom of motion is provided according to a specific embodiment of the present invention, which specifically includes the following steps.

[0053] S1. The system mode shape of the dual-degree-of-freedom piston pump is obtained through finite element dynamic characteristic analysis. The vibration acceleration test points are determined based on the system mode shape of the dual-degree-of-freedom piston pump.

[0054] The dynamic model of the double-motion-degree-of-freedom piston pump rotor system is constructed by using ANSYS, it is confirmed that the working speed of the double-motion-degree-of-freedom piston pump system is 8000 rpm, rotating around the motor shaft, the contact type between each component in the prototype model is set as Bonded and No Separation, respectively, and the system dynamics characteristics are completed; it is confirmed that the first test point is arranged on the installation base, which belongs to the vibration transmission channel outward; the second test point is selected on the prototype wall, which is a sensitive point of vibration characteristics and is more suitable for vibration characteristic analysis; the first-order critical speed of the prototype is about 15000 rpm, which is greater than the rated working speed 8000 rpm of the system, and the working state does not cross the first-order critical speed.

[0055] S2, install and arrange a high-temperature vibration signal test system.

[0056] The vibration acceleration sensor CAYD136 or CAYD3141 is arranged at the determined test point, pre-testing is carried out, and it is confirmed that the instrument is reasonably selected. The mounting thread of the vibration acceleration sensor is fastened to prevent loosening caused by excessive vibration level. The vibration acceleration sensor is connected to the signal acquisition instrument INV3062C1, and the vibration acceleration sensor interacts with the data analysis system through the signal acquisition instrument.

[0057] S3, respectively, from the radial and axial excitation of the measured prototype, the measured prototype is started to run at the rated working condition, the acceleration sensor is used to test the radial and axial time domain of the measured prototype, the data acquisition system collects the vibration signal and transmits it to the data analysis system.

[0058] The elastic hammer is used to excite the measured prototype from the axial and radial directions, the measured prototype is started to run to the rated working condition, the vibration acceleration sensor CAYD136 or CAYD3141 is used to collect the time domain vibration signal of the measured prototype, and the vibration data under different working conditions and excitation modes are transmitted to the signal acquisition instrument INV3062C1.

[0059] S4, the data analysis system identifies the modal parameters of the pump system and analyzes the vibration characteristics according to the vibration signal, obtains the modal shape of each order of the measured prototype, determines the natural frequency of each order of the system, and obtains the vibration characteristic parameters under high-temperature working condition.

[0060] The vibration data collected by the vibration acceleration sensor are post-processed and analyzed, and the time domain characteristics and frequency domain characteristics of the measured prototype are obtained, as shown in Figure 2 and Figure 3 The modal shape of each order is obtained. The vibration is mainly characterized by impact signals, with 4 pulse impacts in one cycle and a cycle of 98.9257 ms; the frequency spectrum characteristics are similar to the time domain characteristics, and the results show that the working frequency of the pump is about 200 Hz.

[0061] With the simulation results obtained by using the ANSYS finite element analysis method, the simulation model is corrected, and the test precision is further improved.

[0062] In this embodiment, only 0.1-2KHz is taken as the analysis range.

[0063] In this vibration test method, the following points should be noted:

[0064] (1) The acceleration sensor should be installed on a smooth surface, and for the test machine with large vibration amplitude, the threaded installation form should be adopted; before testing, the test machine should be excited, and whether the signal gain device is matched should be adjusted.

[0065] (2) In order to ensure the test precision and the safety of the equipment, the sensor suitable for the test range should be determined under the state of exciting vibration.

[0066] (3) During the test, the test should be carried out from different measuring points according to the working environment, so as to ensure the measurement accuracy.

[0067] In summary, the application provides a double-motion-degree-of-freedom piston pump vibration test method, which completes the vibration test of the double-motion-degree-of-freedom piston pump through the steps of finite element modal analysis, vibration acceleration test point arrangement, test machine excitation test, vibration parameter identification analysis, etc., can effectively identify the system modal characteristic parameters of the double-motion-degree-of-freedom piston pump, obtain the vibration characteristics of the test machine under high temperature and other working conditions through experimental means, effectively improve the test efficiency and data accuracy, and ensure the stable operation of the high-temperature state system.

[0068] The above only describes the preferred embodiments of the application and is not used to limit the application. For those skilled in the art, the application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application should be included in the protection scope of the application.

Claims

1. A method of testing a dual-motion-degree-of-freedom piston pump for vibration, the method comprising: The double-motion-degree-of-freedom piston pump vibration test method comprises the following steps: S1, obtaining the system modal shape of the double-motion-degree-of-freedom piston pump through finite element dynamics characteristic analysis, and determining the vibration acceleration test point according to the system modal shape of the double-motion-degree-of-freedom piston pump; S2, installing a high-temperature vibration signal test system; S3, exciting the double-motion-degree-of-freedom piston pump to be tested from the radial direction and the axial direction respectively, starting the to-be-tested sample machine to run at the rated working condition, and performing time-domain test on the to-be-tested sample machine in the radial direction and the axial direction by using the vibration acceleration sensor, collecting the vibration signal by using the data acquisition system, and transmitting the vibration signal to the data analysis system; S4, performing modal parameter identification and vibration characteristic analysis on the pump system according to the vibration signal, obtaining the modal shape of each order of the to-be-tested sample machine, determining the natural frequency of each order of the system, and obtaining the vibration characteristic parameter under the high-temperature working condition; In S1, the finite element dynamics characteristic analysis specifically comprises the following steps: establishing a finite element analysis model of the double-motion-degree-of-freedom piston pump; confirming the technical state of the to-be-tested sample machine, taking the working speed as the analysis input condition, completing the system dynamics characteristic analysis, and obtaining the system modal shape of each order; and realizing the finite element analysis by using ANSYS or ABAQUS; In S4, the collected vibration signal is processed by using the DASP vibration analysis software to obtain the time-domain characteristic and the frequency-domain characteristic curve, the modal parameter of the pump system is identified, and the modal shape of each order is obtained; After obtaining the modal shape of each order of the to-be-tested sample machine, the double-motion-degree-of-freedom piston pump vibration test method further comprises the following steps: correcting the system modal shape obtained by the finite element dynamics characteristic analysis simulation in S1 according to the modal shape of each order of the to-be-tested sample machine, and adjusting the vibration acceleration test point; The double-motion-degree-of-freedom piston pump vibration test system used in the double-motion-degree-of-freedom piston pump vibration test method comprises a sample machine installation platform, a vibration acceleration sensor, a test loading system, a medium temperature control and protection system, a medium circulation system, a data acquisition system, a data analysis system, an electrical control system, and an upper computer interaction system; the sample machine installation platform is used for installing the to-be-tested sample machine; the vibration acceleration sensor is installed at the vibration acceleration test point; the test loading system is used for exciting the to-be-tested sample machine from the radial direction and the axial direction respectively; the medium temperature control and protection system is used for adjusting and setting the environmental temperature of the to-be-tested sample machine; the medium circulation system is used for realizing the circulation control of the temperature control medium; the data acquisition system collects the vibration signal obtained by the vibration acceleration sensor and transmits the vibration signal to the data analysis system; the data analysis system realizes data interaction with the outside world through the upper computer interaction system; and the electrical control system is used for electrical control of the vibration test system.

2. The dual-motion-degree-of-freedom piston pump vibration test method of claim 1, wherein, S2 specifically comprises the following steps: installing the to-be-tested sample machine on the sample machine installation platform, installing the test loading system, the medium temperature control and protection system, the medium circulation system, the data acquisition system, the data analysis system, the electrical control system, and the upper computer interaction system; installing the vibration acceleration sensor at the vibration acceleration test point, and realizing data interaction between the vibration acceleration sensor and the data analysis system through the data acquisition system.

3. The dual-motion-degree-of-freedom piston pump vibration test method of claim 1, wherein, In S3, the force hammer is used to excite the test machine from radial and axial directions respectively.

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