Propulsion motor wide temperature range low pressure loading test method

Abstract

The application discloses a wide-temperature-range low-air-pressure loading test method for a propulsion motor, relates to the field of propulsion motor testing, and aims at simulating high-altitude and high-altitude severe climate environment conditions by comprehensively considering wide-temperature-range high-low temperature alternating stress, variable environmental pressure stress, mechanical vibration and impact stress caused by air flow disturbance and alternating load stress. The application can realize comprehensive and accurate evaluation on the performance of the propulsion motor.

Description

Technical Field

[0001] This invention relates to the field of propulsion motor testing, and more particularly to a method for testing propulsion motors under low air pressure in a wide temperature range. Background Technology

[0002] The core of electric propulsion lies in replacing traditional fossil fuels with electricity as the driving force for aircraft. Electric propulsion technology has attracted widespread attention due to its numerous significant advantages, including higher energy efficiency, lower operating costs, zero emissions, low noise, support for distributed deployment and rapid response control capabilities, and higher system reliability and safety. Currently, this technology is gradually extending from low-altitude, short-range flight applications to ultra-high-altitude, long-endurance missions. However, the operating environment of propulsion motors differs significantly from that of motors under normal temperature and pressure conditions. Especially under multiple coupled conditions such as ultra-low temperatures, low air pressure, and complex airflow changes, material properties, mechanical properties, and electromagnetic properties may all experience significant degradation or nonlinear changes. Therefore, there is an urgent need to propose an advanced propulsion motor loading test method to effectively simulate the multi-physics coupled stress environment, realistically reproduce the operating state of propulsion motors under high-altitude, low-pressure conditions, thereby deeply revealing its performance evolution mechanism, optimizing design methods, and improving key performance indicators. Summary of the Invention

[0003] Because propulsion motors operate in high-altitude, high-altitude environments, they face complex environmental conditions such as low temperatures, low air density, and turbulent airflow. These factors significantly alter the physical properties of the materials used in the motor, thereby having a significant impact on its electromagnetic performance, mechanical reliability, and thermal management capabilities. Therefore, the performance testing of aircraft propulsion motors differs fundamentally from motor testing under normal temperature and pressure conditions. To address the urgent need for propulsion motor performance testing and solve the aforementioned technical problems, this invention proposes a wide-temperature-range, low-pressure loading test method for propulsion motors. This method comprehensively considers alternating high and low temperature stresses over a wide temperature range, varying environmental pressure stresses, mechanical vibration and impact stresses induced by airflow disturbances, and alternating load stresses. It simulates harsh climatic conditions at high altitudes and high altitudes, enabling a comprehensive and accurate evaluation of propulsion motor performance.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A method for testing a propulsion motor under wide temperature range and low atmospheric pressure includes: installing a motor-to-tow test platform on a digital electromagnetic vibration table and placing the entire platform within the test chamber of a full-temperature-range thermal vacuum test apparatus; providing temperature stress and environmental pressure stress through the full-temperature-range thermal vacuum test apparatus, providing mechanical vibration and impact stress through the digital electromagnetic vibration table, and providing motor load stress through the motor-to-tow test platform; implementing synchronous static coupling loading, setting multiple static test points during changes in temperature, environmental pressure, mechanical vibration and impact, motor load torque, and speed parameters to test the performance of the propulsion motor under different steady-state conditions; and implementing alternating cyclic dynamic synchronous coupling loading to test the temperature... The system combines stress, environmental pressure stress, mechanical vibration and impact stress, and motor load stress in pairs, triplets, or quadruplets to simulate the complex climatic conditions during the aircraft's takeoff and long-term stationary phases. It conducts comprehensive accelerated life tests, constructing acceleration factors under multi-stress coupling conditions by combining the Arrhenius model temperature model, the Coffin-Manson fatigue life model, and the Mainner linear cumulative damage theory. A model parameter correction mechanism is introduced to monitor test criteria and estimate the expected service life of the propulsion motor. Finally, it conducts single-item limit performance tests, determining the safe operating boundaries of the propulsion motor under different airspace or altitude conditions by fixing three stress parameters and adjusting one.

[0006] Furthermore, the synchronous static coupling loading includes: during the change from normal temperature and pressure ground conditions to complex high-altitude environmental conditions such as ultra-low temperature, low air pressure and strong airflow disturbance, a static test point is set at each interval of 5°C for temperature, 5kPa for environmental pressure, 0.5g for mechanical vibration and impact, and 5% of the rated value for motor load torque and speed, to collect the performance parameters of the propulsion motor.

[0007] Furthermore, the alternating cyclic dynamic synchronous coupling loading includes: arbitrarily combining temperature stress, environmental pressure stress, mechanical vibration and impact stress, and motor load stress to simulate the impact of altitude changes, temperature fluctuations, airflow disturbances, and load variations on propulsion motor performance during the aircraft's ascent, as well as the environment of alternating day and night temperature differences, short-term strong wind impacts, and severe airflow disturbances during long-term stationary phases.

[0008] Furthermore, the comprehensive accelerated life test includes: designing a comprehensive accelerated life test scheme under multi-stress coupling conditions based on the Arrhenius model temperature model, the Coffin-Manson fatigue life model and the Mainner linear cumulative damage theory; introducing a model parameter correction mechanism to correct the acceleration factor under multi-stress coupling conditions; and estimating the expected service life of the propulsion motor through monitoring test criteria.

[0009] Furthermore, the single-item extreme performance test includes: based on the meteorological law that atmospheric pressure and ambient temperature change synchronously with altitude, setting atmospheric pressure and ambient temperature conditions corresponding to different airspaces or altitudes, and monitoring the motor performance response when mechanical vibration and impact increase by 0.5g, and load torque and speed increase by 5% of the rated value, until the maximum impact load and maximum overload multiple that the motor can withstand under each altitude condition are determined; starting from normal temperature and pressure, motor parameters are collected every 5°C to determine the highest and lowest safe operating temperatures of the propulsion motor under normal pressure conditions; starting from standard atmospheric pressure, data monitoring is conducted every 5kPa decrease to test the minimum atmospheric pressure limit at which the propulsion motor can operate normally.

[0010] Furthermore, the digital electromagnetic vibration table is designed to withstand high and low temperatures, and applies independent or arbitrarily coupled vibrations in six directions (up, down, left, right, front, and back) to the motor-to-tow test platform, providing sinusoidal and random vibration excitations to simulate complex operating conditions caused by severe airflow disturbances in high-altitude and high-altitude environments.

[0011] Furthermore, the load motor in the motor-to-tow test platform not only applies a constant torque to complete the load capacity test under various working conditions, but also excites the motor shaft system to generate torsional vibration through sudden increases or decreases in torque. This torsional vibration, together with the overall random vibration of the motor-to-tow test platform, constitutes a multi-source coupled excitation, simulating the complex vibration environment that the propulsion motor is subjected to under complex climatic conditions.

[0012] Furthermore, the mechanical components of the motor-driven test platform adopt a non-rigid connection cooperative matching design, including a diaphragm coupling, torque and speed meter, coupling, gearbox, and diaphragm disc coupling, to compensate for the thermal expansion and contraction effect under high and low temperature environments.

[0013] Furthermore, the diaphragm coupling is integrally machined from spring steel, possessing angular misalignment compensation and axial expansion / contraction compensation capabilities; a floating bearing is configured at one end of the gearbox, and the gear meshing clearance is reserved at no less than 10% of the tooth height, providing tolerance for axial and radial deviations; the diaphragm coupling retains axial play to accommodate minor displacements during installation and testing.

[0014] Furthermore, the mechanical components of the motor-driven test platform adopt a non-rigid connection structure. The propulsion motor is sequentially connected to the diaphragm coupling, torque and speed meter, coupling, gearbox, diaphragm coupling and load motor. The load motor applies torque to the propulsion motor through this mechanical component. The load motor is driven by the propulsion motor and operates in generator mode. The generated voltage and current are dissipated as heat energy through a three-phase AC resistance load box.

[0015] Beneficial effects:

[0016] 1. Traditional motor loading test methods typically apply load stress under normal temperature and pressure conditions, rarely considering the simultaneous coupling of multiple factors such as wide temperature range, low air pressure, and external vibration and impact on motor performance. The method proposed in this invention not only covers ground operation condition testing under normal temperature and pressure conditions, but also systematically introduces wide-range high and low temperature alternating cyclic stress, variable environmental pressure stress, mechanical vibration and impact stress induced by airflow disturbance, and dynamic variable load stress, aiming to simulate complex operating conditions in high-altitude and high-altitude harsh climatic environments. The constructed multi-physics coupled stress loading environment achieves comprehensive simulation capabilities not possessed by traditional motor loading test methods, demonstrating significant technological advancement.

[0017] 2. Traditional loading test methods mainly focus on the performance testing of motors under steady-state conditions, rarely involving dynamic synchronous coupling loading under multi-stress alternating cyclic conditions. In contrast, the method proposed in this invention, through the synergistic coupling loading of temperature stress, environmental pressure stress, mechanical vibration and impact stress, and motor load stress, can effectively simulate the comprehensive impact of factors such as altitude changes, temperature fluctuations, airflow disturbances, and load variations on the performance of propulsion motors during aircraft takeoff. Simultaneously, it can also reproduce the motor's performance response characteristics under complex environmental conditions such as alternating day and night temperature differences during long-term stationary phases, short-term strong wind impacts, and severe airflow disturbances. This systematic multi-physics coupling simulation method has not been reported in existing published literature and possesses significant technological innovation.

[0018] 3. Regarding the testing of single-item extreme performance of motors, there are significant differences in diurnal temperature variations at the same altitude, and under the same altitude conditions, motors may face significantly different climatic conditions, such as calm weather and short-term strong wind impacts. Airflow disturbances also vary considerably across different airspaces. The method proposed in this invention can not only evaluate the motor's highest and lowest safe operating temperatures under normal pressure conditions and its operational capabilities in extreme low-pressure environments, but also simulate the maximum impact load and maximum overload multiple under different airspace or altitude conditions. This invention can simulate and test single-item extreme performance under various possible airspace environmental conditions by fixing the other three environmental parameters. In contrast, conventional motor testing methods have limited coverage of single-item extreme operating conditions and cannot comprehensively reflect the impact of multi-dimensional harsh climatic environments on motor performance.

[0019] 4. Conventional motor loading tests mainly focus on evaluating motor performance parameters, lacking a systematic analysis of expected service life; while traditional reliability aging tests are usually based on a single model, making it difficult to truly reflect the complexity of actual operating conditions. In contrast, this invention not only introduces a motor accelerated life test method, but also combines the Arrhenius temperature model, the Coffin-Manson fatigue life model, and Miner's linear cumulative damage theory to construct an acceleration factor under multi-stress coupling conditions. The multi-stress coupling acceleration factor is not a simple multiplication of single acceleration factors but has a coupling coefficient. Therefore, a model parameter correction mechanism is introduced to correct the acceleration factor under multi-stress coupling conditions, and a comprehensive accelerated life test under the synergistic effect of multiple stresses is carried out, significantly improving the matching degree between the test conditions and the actual complex operating environment, thereby effectively improving the confidence level of the life prediction results.

[0020] 5. In traditional motor loading tests, the motor-to-torque test platform typically operates under normal temperature and pressure conditions, resulting in limited simulation capabilities. This invention integrates the motor-to-torque test platform into a digital electromagnetic vibration table and places the entire platform within the test chamber of a full-temperature-range thermal vacuum testing device. This enables coupled and coordinated loading tests of multiple physical field environments, including temperature, air pressure, mechanical vibration, and impact. Through modifications to the hardware platform and the development of innovative loading methods, the simulated operating conditions of the loading test are significantly expanded, successfully simulating operating environments under high altitude, ultra-high altitude, and complex climatic conditions.

[0021] 6. This invention simulates the vibration and impact conditions experienced by a propulsion motor when encountering short-term strong wind impacts or severe airflow disturbances by implementing independent or coupled vibration loading of six degrees of freedom. Compared with wind tunnel testing to simulate strong winds or severe airflow, this method significantly reduces testing costs while ensuring the realism of the simulation.

[0022] 7. Common motor-to-motor test platforms almost never consider the impact of torsional vibration of the motor shaft system on performance, and are even less able to simulate the torsional vibration behavior of the motor shaft system under high altitude, low air pressure, and complex climatic conditions. This invention not only applies external overall vibration and impact through a digital electromagnetic vibration table, but also applies sudden increases or decreases in torque at the load motor end to excite the torsional vibration response of the motor shaft system. The torsional vibration of the shaft system and the overall random vibration of the motor-to-motor test platform form a multi-source coupled excitation, which can effectively simulate the complex vibration environment experienced by the propulsion motor under complex climatic conditions, thereby verifying its vibration resistance under actual operating conditions.

[0023] 8. The mechanical components in this invention all employ a non-rigid connection structure with a coordinated matching design to compensate for deformation caused by thermal expansion and contraction under high and low temperature environments. The diaphragm coupling has the ability to compensate for angular misalignment and axial expansion and contraction; one end of the gearbox is equipped with a floating bearing, and the gears have reserved meshing clearance, providing tolerance for axial and radial deviations; the diaphragm coupling allows for small axial displacements. The above-mentioned coordinated matching design ensures the operational stability, connection reliability, deviation tolerance, and ease of installation and debugging of the test platform system under large temperature difference conditions from multiple dimensions. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the loading test device involved in the loading test method for a propulsion motor under wide temperature range and low air pressure according to the present invention;

[0025] Figure 2 This is a schematic diagram showing the distribution of various equipment on the motor-assisted drag test platform;

[0026] The attached figures are labeled as follows: 1. Full-temperature zone thermal vacuum test equipment; 2. Motor-driven test platform; 3. Digital electromagnetic vibration table; 4. Propulsion motor; 5. Diaphragm coupling; 6. Torque-speed meter; 7. Coupling; 8. Gearbox; 9. Diaphragm disc coupling; 10. Load motor. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0028] This invention provides a wide-temperature-range low-pressure loading test method for propulsion motors, which can simultaneously apply temperature stress, environmental pressure stress, mechanical vibration and impact stress, and motor load stress to complete synchronous static coupled loading, used to evaluate the performance of propulsion motors under steady-state conditions; it supports alternating cyclic dynamic synchronous coupled loading to examine its response characteristics under transient conditions; it designs a comprehensive accelerated life test scheme under multi-stress coupling conditions, introduces a model parameter correction mechanism to correct the acceleration factor under multi-stress coupling conditions, and estimates the expected service life of the propulsion motor by monitoring test criteria; it also has a single stress independent adjustment function, which can be used for single-item extreme performance testing under different airspace or altitude conditions.

[0029] Furthermore, the synchronous static coupling loading method includes: during the change from normal temperature and pressure ground conditions to complex high-altitude environmental conditions such as ultra-low temperature, low air pressure, and strong airflow disturbance, a static test point is set at each interval of 5°C for temperature, 5kPa for environmental pressure, 0.5g for mechanical vibration and impact, and 5% of the rated value for motor load torque and speed, to test the performance of the propulsion motor under different steady-state conditions.

[0030] Furthermore, the alternating cyclic dynamic synchronous coupling loading method includes: combining temperature stress, environmental pressure stress, mechanical vibration and impact stress, and motor load stress in pairs, in triplicate, or in any combination of four to simulate the impact of altitude changes, temperature fluctuations, airflow disturbances, and load variations on the propulsion motor performance during the aircraft's ascent, in order to evaluate the propulsion motor's ability to withstand complex climatic conditions such as alternating day and night temperature differences, short-term strong wind impacts, and severe airflow disturbances during long-term stationary phases.

[0031] Furthermore, the comprehensive accelerated life test scheme includes: designing a comprehensive accelerated life test scheme under multi-stress coupling conditions based on the Arrhenius temperature model, the Coffin-Manson fatigue life model and the Miner linear cumulative damage theory; introducing a model parameter correction mechanism to correct the acceleration factor under multi-stress coupling conditions; and estimating the expected service life of the propulsion motor by monitoring test criteria.

[0032] Arrhenius temperature model and its accelerating factor The calculation formulas are as follows:

[0033] ;

[0034] ;

[0035] in, The lifetime characteristic is expressed in hours (h); A is the frequency factor constant. The activation energy of the failure mechanism is expressed in electron volts (eV); K is the Boltzmann constant, with a value of 8.617. 10 -5 eV / K; This is absolute temperature, measured in Kelvin (K). It is a temperature acceleration factor; The absolute temperature under normal operating conditions of the product is expressed in Kelvin (K). The absolute temperature under accelerated test conditions is expressed in Kelvin (K); exp() represents an exponential function.

[0036] Coffin-Manson fatigue life model and its acceleration factor The calculation formulas are as follows:

[0037] ;

[0038] ;

[0039] in, It is the plastic strain amplitude; It is the fatigue ductility coefficient; It is the number of loops until failure; It is the fatigue ductility index, with a value ranging from -0.5 to -0.7; and These are the cycle frequencies under conditions 1 and 2, respectively, in Hz; and These are the differences between the highest and lowest temperatures under conditions 1 and 2, respectively, in Kelvin (K). The activation energy of the failure mechanism is expressed in electron volts (eV); K is the Boltzmann constant, with a value of 8.617. 10 -5 eV / K; This is the highest temperature under condition 2. This is the highest temperature under condition 1.

[0040] Miner's linear cumulative damage theory and its acceleration factor The calculation formulas are as follows:

[0041] ;

[0042] ;

[0043] in, Total cumulative damage; In the first The actual number of cycles experienced under a given stress level; This represents the total number of cycles required for a single stress action to cause failure at a constant stress level. The total number of different stress levels experienced. Let be the acceleration factor from condition A to condition B; This refers to the number of cycles to failure under accelerated testing conditions. This represents the number of cycles until failure under actual usage conditions.

[0044] In the designed comprehensive accelerated life test scheme, the acceleration factor under multi-stress coupling conditions The calculation formula is:

[0045] ;

[0046] in, The coupling coefficient is the stress coupling coefficient of the three components. This indicates that the number of coupled stresses is 3, and the coupling coefficient is applied to the pairwise, triadic, or quadrangular couplings between different stresses. , , It is different; it is not a simple multiplication of a single acceleration factor but involves a coupling coefficient. In order to accurately obtain the coupling coefficient, a model parameter correction mechanism is introduced. First, an initial theoretical value is set, and then the acceleration factor under multi-stress coupling conditions is corrected through iterative experimental test data. The product of the actual test time and the acceleration factor under multi-stress conditions is the estimated expected service life.

[0047] Furthermore, the single-item extreme performance test includes: based on the meteorological law that atmospheric pressure and ambient temperature change synchronously with altitude, setting atmospheric pressure and ambient temperature conditions corresponding to different airspaces or altitudes, and monitoring the motor performance response when mechanical vibration and impact increase by 0.5g, and load torque and speed increase by 5% of the rated value, until the maximum impact load and maximum overload multiple that the motor can withstand under each altitude condition are determined; starting from normal temperature and pressure, motor parameters are collected every 5°C to determine the highest and lowest safe operating temperature of the propulsion motor under normal pressure conditions; starting from standard atmospheric pressure, data monitoring is performed every 5kPa decrease to test the minimum atmospheric pressure limit for normal operation.

[0048] Furthermore, in the stress application method (application of temperature stress, environmental pressure stress, mechanical vibration and impact stress, and motor load stress), each stress can be applied individually or coupled when simulating high-altitude climate conditions; wherein, temperature stress and environmental pressure stress are provided by the full-temperature zone thermal vacuum test equipment 1, mechanical vibration and impact stress are applied by the digital electromagnetic vibration table 3, and motor load stress is applied by the motor drag test platform 2 through non-rigidly connected mechanical components; the motor drag test platform 2 is installed on the digital electromagnetic vibration table 3 and is placed entirely in the test chamber of the full-temperature zone thermal vacuum test equipment 1.

[0049] Furthermore, the digital electromagnetic vibration table 3 is designed to withstand high and low temperatures, and can apply independent or arbitrary coupled vibrations in six directions (up and down, left and right, front and back) to the motor-to-tow test platform 2 installed on it to verify the propulsion motor's ability to withstand short-term strong wind impacts in high-altitude environments; at the same time, it can provide sinusoidal vibration and random vibration excitation to simulate complex operating conditions caused by severe airflow disturbances in high-altitude and high-altitude environments.

[0050] Furthermore, the load motor 10 on the motor-to-tow test platform 2 can not only apply a constant torque to complete the load capacity test under various working conditions, but also excite the motor shaft system to generate torsional vibration through sudden increases or decreases in torque; the torsional vibration of the shaft system and the overall random vibration of the motor-to-tow test platform 2 constitute multi-source coupled excitation, which can simulate the complex vibration environment that the propulsion motor is subjected to under complex climatic conditions, thereby verifying its vibration resistance performance under actual operating conditions.

[0051] Furthermore, the mechanical components include the diaphragm coupling 5, torque and tachometer 6, coupling 7, gearbox 8, and diaphragm disc coupling 9, which collectively refer to all mechanical connection components between the propulsion motor 4 and the load motor 10. These mechanical components employ a non-rigid connection and coordinated matching design to compensate for thermal expansion and contraction under high and low temperature environments. The diaphragm disc coupling 9 is integrally machined from spring steel and possesses angular misalignment compensation and axial expansion / contraction compensation capabilities. A floating bearing is configured at one end of the gearbox, and the gear meshing clearance is reserved at no less than 10% of the tooth height, providing tolerance for axial and radial deviations. The diaphragm coupling 5 retains a certain axial play to accommodate minor displacements during installation and testing.

[0052] Example:

[0053] like Figure 1 As shown, in the loading test device involved in the wide-temperature-range low-pressure propulsion motor loading test method of the present invention, each stress can be applied individually or coupled when simulating high-altitude climate conditions; wherein, temperature stress and environmental pressure stress are provided by the full-temperature-range thermal vacuum test equipment 1, mechanical vibration and impact stress are applied by the digital electromagnetic vibration table 3, and motor load stress is applied by the motor-to-tow test platform 2 through non-rigidly connected mechanical components; the motor-to-tow test platform 2 is installed on the digital electromagnetic vibration table 3 and is placed entirely in the test chamber of the full-temperature-range thermal vacuum test equipment 1.

[0054] The full-temperature-range thermal vacuum testing equipment 1 has a temperature adjustment range of -150℃ to +150℃ and an ultimate vacuum level better than 5.0. 10 -5Pa, temperature rate ≥2℃ / min. The digital electromagnetic vibration table 3 is designed to withstand high and low temperatures, and can apply independent or arbitrary coupled vibrations in six directions (up / down, left / right, front / back) to the motor-to-tow test platform 2 mounted on it to verify the propulsion motor's ability to withstand short-term strong wind impacts in high-altitude environments; it can also provide sinusoidal vibration and random vibration excitation to simulate complex operating conditions caused by severe airflow disturbances in high-altitude and high-altitude environments. The digital electromagnetic vibration table 3 has a maximum acceleration of 70g, a frequency range of 5~2000Hz, supports independent or coupled vibrations in six directions (up / down, left / right, front / back), and supports sinusoidal and random impacts. The maximum sinusoidal thrust is 35kN, and the maximum impact thrust is 70kN, to verify the propulsion motor's wind resistance performance when encountering short-term strong winds (wind force above level 6); it can also provide sinusoidal vibration or random vibration impacts to simulate complex operating conditions in high-altitude and high-altitude environments (-85℃, 5kPa).

[0055] During the wide-temperature-range low-pressure loading test of the propulsion motor, temperature stress, environmental pressure stress, mechanical vibration and impact stress, and motor load stress can be applied simultaneously to complete static coupled loading, which is used to evaluate the performance of the propulsion motor under steady-state conditions. It supports alternating cyclic dynamic synchronous coupled loading to examine its response characteristics under transient conditions. It designs a comprehensive accelerated life test scheme under multi-stress coupling conditions, introduces a model parameter correction mechanism to correct the acceleration factor under multi-stress coupling conditions, and estimates the expected service life of the propulsion motor by monitoring test criteria. It also has a single stress independent adjustment function, which can be used for single extreme performance tests under different airspace or altitude conditions.

[0056] During the synchronous static coupling loading process, as the ground conditions change from normal temperature and pressure (-20℃~+55℃, 101kPa) to complex high-altitude environmental conditions with ultra-low temperature, low air pressure and strong airflow disturbance (-85℃, 5kPa), a static test point is set at each interval of 5℃ for temperature, 5kPa for environmental pressure, 0.5g for mechanical vibration and shock, and 5% for motor load torque and speed, to test the performance of the propulsion motor under different steady-state conditions.

[0057] During the alternating cyclic dynamic synchronous coupling loading process, temperature stress, environmental pressure stress, mechanical vibration and impact stress, and motor load stress can be combined in pairs, in triplicate, or in any combination of four to simulate the impact of altitude changes, temperature fluctuations, airflow disturbances, and load variations on the propulsion motor performance during the aircraft's ascent. This allows for the evaluation of the propulsion motor's ability to withstand complex climatic conditions such as alternating day and night temperature differences, short-term strong winds (winds of force 6 or above), and severe airflow disturbances during long-term stationary phases.

[0058] In the process of comprehensive accelerated life testing, based on the Arrhenius temperature model, the Coffin-Manson fatigue life model and Miner linear cumulative damage theory, a comprehensive accelerated life test scheme under multi-stress coupling conditions is designed. A model parameter correction mechanism is introduced to correct the acceleration factor under multi-stress coupling conditions. By monitoring test criteria, the expected service life of the propulsion motor is estimated.

[0059] During the single-item extreme performance test, based on the meteorological law that atmospheric pressure and ambient temperature change synchronously with altitude, atmospheric pressure and ambient temperature conditions corresponding to different airspaces or altitudes were set. The motor performance response was monitored for every 0.5g increase in mechanical vibration and impact, and every 5% increase in load torque and speed to the rated value, until the maximum impact load and maximum overload multiple that the motor can withstand under each altitude condition were determined. Starting from normal temperature and pressure (-20℃~+55℃, 101kPa), motor parameters were collected every 5℃ to determine the highest and lowest safe operating temperature of the propulsion motor under normal pressure conditions. Starting from standard atmospheric pressure (101kPa), data monitoring was conducted every 5kPa decrease to test the minimum atmospheric pressure limit for normal operation.

[0060] like Figure 2 As shown, the propulsion motor 4 is sequentially connected to the diaphragm coupling 5, torque and tachometer 6, coupling 7, gearbox 8, diaphragm coupling 9, and load motor 10. The load motor 10 can not only apply a constant torque to complete load capacity tests under various working conditions, but also excite the motor shaft system to generate torsional vibration through sudden increases or decreases in torque. The torsional vibration of the shaft system and the overall random vibration of the motor-driven test platform 2 constitute multi-source coupled excitation, which can simulate the complex vibration environment experienced by the propulsion motor 4 under complex climatic conditions, thereby verifying its vibration resistance performance under actual operating conditions. The load motor 10 applies torque to the propulsion motor 4 through the mechanical components consisting of the diaphragm coupling 9, gearbox 8, and diaphragm coupling 5. During this process, the load motor 10 is driven by the propulsion motor 4 and operates in generator mode, and the generated voltage and current are dissipated as heat energy through a three-phase AC resistive load box.

[0061] The mechanical components of the motor-driven test platform 2 adopt a non-rigid connection collaborative design to compensate for the thermal expansion and contraction effects under high and low temperature environments. The diaphragm coupling 9 is integrally machined from spring steel and has the ability to compensate for angular misalignment and axial expansion and contraction. One end of the gearbox 8 is equipped with a floating bearing, and the gear meshing clearance is reserved by no less than 10% of the tooth height, which has the fault tolerance capability for axial and radial deviations. The diaphragm coupling 5 retains a certain amount of axial movement margin to accommodate small displacements during installation and testing.

[0062] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements 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 testing a propulsion motor under low air pressure over a wide temperature range, characterized in that, include: The motor-driven test platform is installed on a digital electromagnetic vibration table and placed entirely within the test chamber of a full-temperature thermal vacuum test equipment. The system employs a full-temperature-range thermal vacuum testing facility to provide temperature and environmental pressure stresses, a digital electromagnetic vibration table to provide mechanical vibration and impact stresses, and a motor-to-tow test platform to provide motor load stresses. Synchronous static coupled loading is implemented, setting multiple static test points during changes in temperature, environmental pressure, mechanical vibration and impact, motor load torque, and speed parameters to test the propulsion motor's performance under different steady-state conditions. Alternating cyclic dynamic synchronous coupled loading is implemented, combining temperature stress, environmental pressure stress, mechanical vibration and impact stress, and motor load stress in pairs, triplets, or quadruplets to simulate the complex climatic conditions during aircraft takeoff and long-term stationary phases. Comprehensive accelerated life testing is conducted, combining the Arrhenius model temperature model, the Coffin-Manson fatigue life model, and the Mainner linear cumulative damage theory to construct an acceleration factor under multi-stress coupling conditions, introducing a model parameter correction mechanism to monitor test criteria and estimate the expected service life of the propulsion motor. Single-item limit performance testing is implemented, determining the safe operating boundary of the propulsion motor under different airspace or altitude conditions by fixing three stress parameters and adjusting one stress parameter. The mechanical components of the motor-driven test platform adopt a non-rigid connection and coordinated matching design, including a diaphragm coupling, torque and speed meter, coupling, gearbox and diaphragm disc coupling, to compensate for the thermal expansion and contraction effect under high and low temperature environments.

2. The method for testing a propulsion motor under wide temperature range and low air pressure according to claim 1, characterized in that, The synchronous static coupling loading includes: during the change from normal temperature and pressure ground conditions to complex high-altitude environmental conditions such as ultra-low temperature, low air pressure and strong airflow disturbance, a static test point is set at each interval of 5°C for temperature, 5kPa for environmental pressure, 0.5g for mechanical vibration and impact, and 5% of the rated value for motor load torque and speed, to collect the performance parameters of the propulsion motor.

3. The method for testing a propulsion motor under wide temperature range and low air pressure according to claim 1, characterized in that, The alternating cyclic dynamic synchronous coupling loading includes: arbitrarily combining temperature stress, environmental pressure stress, mechanical vibration and impact stress, and motor load stress to simulate the impact of altitude changes, temperature fluctuations, airflow disturbances, and load variations on propulsion motor performance during the aircraft's ascent, as well as the environment of alternating day and night temperature differences, short-term strong wind impacts, and severe airflow disturbances during long-term stationary phases.

4. The method for testing a propulsion motor under wide temperature range and low air pressure according to claim 1, characterized in that, The comprehensive accelerated life test includes: designing a comprehensive accelerated life test scheme under multi-stress coupling conditions based on the Arrhenius model temperature model, the Coffin-Manson fatigue life model and the Mainner linear cumulative damage theory; introducing a model parameter correction mechanism to correct the acceleration factor under multi-stress coupling conditions; and estimating the expected service life of the propulsion motor through monitoring test criteria.

5. The method for testing a propulsion motor under wide temperature range and low air pressure according to claim 1, characterized in that, The single-item extreme performance test includes: based on the meteorological law that atmospheric pressure and ambient temperature change synchronously with altitude, setting atmospheric pressure and ambient temperature conditions corresponding to different airspaces or altitudes, and monitoring the motor performance response when mechanical vibration and impact increase by 0.5g, and load torque and speed increase by 5% of the rated value, until the maximum impact load and maximum overload multiple that the motor can withstand under each altitude condition are determined; starting from normal temperature and pressure, motor parameters are collected every 5°C to determine the highest and lowest safe operating temperature of the propulsion motor under normal pressure conditions; starting from standard atmospheric pressure, data monitoring is performed every 5kPa decrease to test the minimum atmospheric pressure limit at which the propulsion motor can operate normally.

6. The method for testing a propulsion motor under wide temperature range and low air pressure according to claim 1, characterized in that, The digital electromagnetic vibration table is designed to withstand high and low temperatures. It applies independent or arbitrarily coupled vibrations in six directions (up, down, left, right, front, and back) to the motor-to-tow test platform, providing sinusoidal and random vibration excitations to simulate complex operating conditions caused by severe airflow disturbances in high-altitude and high-altitude environments.

7. The method for testing a propulsion motor under wide temperature range and low air pressure according to claim 1, characterized in that, The load motor in the motor-to-tow test platform not only applies a constant torque to complete load capacity tests under various working conditions, but also excites the motor shaft system to generate torsional vibration through sudden increases or decreases in torque. This torsional vibration, together with the overall random vibration of the motor-to-tow test platform, constitutes a multi-source coupled excitation, simulating the complex vibration environment that the propulsion motor is subjected to under complex climatic conditions.

8. The method for testing a propulsion motor under wide temperature range and low air pressure according to claim 1, characterized in that, The diaphragm coupling is integrally machined from spring steel and has the ability to compensate for angular misalignment and axial expansion and contraction. One end of the gearbox is equipped with a floating bearing, and the gear meshing clearance is reserved by no less than 10% of the tooth height, which has the ability to tolerate axial and radial deviations. The diaphragm coupling retains axial play to accommodate small displacements during installation and testing.

9. The method for testing a propulsion motor under wide temperature range and low air pressure according to claim 1, characterized in that, The mechanical components of the motor-driven test platform adopt a non-rigid connection structure. The propulsion motor is sequentially connected to the diaphragm coupling, torque and speed meter, coupling, gearbox, diaphragm coupling and load motor. The load motor applies torque to the propulsion motor through this mechanical component. The load motor is driven by the propulsion motor and runs in generator mode. The generated voltage and current are dissipated as heat energy through a three-phase AC resistance load box.

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