A method and system for evaluating the state of a high-speed motor train unit traction motor bearing

Abstract

This invention provides a method and system for assessing the condition of traction motor bearings in high-speed trains, relating to the field of electrified rail transit technology. The method includes obtaining wear and corrosion impact parameters of the traction motor bearing to be assessed; constructing a wear equation for the traction motor bearing based on the wear impact parameters; constructing a corrosion equation for the traction motor bearing based on the corrosion impact parameters; coupling the wear equation and the corrosion equation to obtain a dynamic damage coupling equation; introducing a life decay function into the dynamic damage coupling equation to obtain a dynamic fully coupled life model; and using the dynamic fully coupled life model to assess the condition of the traction motor bearing to be assessed, obtaining the remaining life under different operating conditions. This invention solves the problem of accurately quantifying the degree of damage and assessing the remaining life under different operating conditions under the synergistic effect of wear and corrosion.

Description

Technical Field

[0001] This invention relates to the field of electrified rail transit technology, and more specifically, to a method and system for assessing the condition of traction motor bearings in high-speed trains. Background Technology

[0002] As a key component of the vehicle's traction system, the bearing of the traction motor in a high-speed train bears the heavy responsibility of support and rotation. The bearing not only needs to withstand high-frequency operation and huge loads, but also needs to resist the effects of various factors such as electrochemical corrosion caused by high-pressure environment. Therefore, the bearing needs to have excellent wear resistance and corrosion resistance to ensure the stable operation of the traction motor and the long-term stable high-speed operation of the vehicle.

[0003] High-speed trains experience various overvoltage conditions during operation, including lightning strike overvoltage, wheel-rail rolling arcing overvoltage, pantograph-catenary disconnection overvoltage, and VCB (vacuum switch) operation overvoltage. Frequent overvoltage impacts significantly affect bearing performance. Furthermore, high-speed movement causes frequent low-frequency vibrations in the car body and related current-collecting equipment, leading to frequent poor contact between the pantograph and the overhead contact line. This results in transient voltage surges into the bearings, exacerbating electrochemical corrosion. These overvoltage phenomena pose severe challenges to bearings in high-speed train operation.

[0004] Furthermore, research indicates that bearing wear and electrochemical corrosion are, to some extent, mutually reinforcing: in a corrosive environment, wear can accelerate the electrochemical reaction, while the reaction products of electrochemical corrosion increase friction, leading to further exacerbation of wear. This complex interaction results in bearings facing a dual crisis during the rapid operation of high-speed trains.

[0005] Therefore, in-depth research on bearing wear and electrochemical corrosion during high-speed rail operation is particularly important. First, it is crucial to improve our understanding of wear and corrosion mechanisms. Second, although numerous studies have focused on the independent effects of wear and electrochemical corrosion, systematic research remains insufficient, especially under the specific operating conditions of high-speed rail. Exploring the complex relationship between these two factors will contribute to establishing a comprehensive bearing life assessment system. Summary of the Invention

[0006] The purpose of this invention is to provide a method and system for assessing the condition of traction motor bearings in high-speed trains, thereby improving the aforementioned problems. To achieve this objective, the technical solution adopted by this invention is as follows:

[0007] Firstly, this application provides a method for condition assessment of traction motor bearings in high-speed trains, including:

[0008] The wear and corrosion impact parameters of the traction motor bearing of the high-speed train to be evaluated are obtained. The wear impact parameters include bearing pressure, bearing speed, ambient temperature and surface roughness. The corrosion impact parameters include discharge quantity, peak voltage and corrosion current.

[0009] Based on the wear influence parameters, a wear equation for the traction motor bearing of the high-speed train to be evaluated is constructed;

[0010] The corrosion equation for the bearing of the traction motor of the high-speed train to be evaluated is constructed based on the corrosion influence parameters.

[0011] By combining the synergistic effects of wear and corrosion, the wear equation and the corrosion equation are coupled to obtain a dynamic damage coupling equation;

[0012] By introducing a lifetime decay function into the dynamic damage coupling equation, a dynamic fully coupled lifetime model is obtained.

[0013] The dynamic fully coupled life model is used to evaluate the condition of the traction motor bearings of the high-speed train under evaluation, and the remaining life under different operating conditions is obtained.

[0014] Secondly, this application also provides a condition assessment system for traction motor bearings of high-speed trains, including:

[0015] The acquisition unit is used to acquire wear influence parameters and corrosion influence parameters of the traction motor bearing of the high-speed train to be evaluated. The wear influence parameters include bearing pressure, bearing speed, ambient temperature and surface roughness, and the corrosion influence parameters include discharge quantity, voltage peak value and corrosion current.

[0016] The first construction unit is used to construct the wear equation of the traction motor bearing of the high-speed train to be evaluated based on the wear influence parameters.

[0017] The second construction unit is used to construct the corrosion equation of the traction motor bearing of the high-speed train to be evaluated based on the corrosion influence parameters.

[0018] A coupling unit is used to combine the synergistic effects of wear and corrosion, coupling the wear equation and the corrosion equation to obtain a dynamic damage coupling equation;

[0019] An adjustment unit is used to introduce a lifetime decay function into the dynamic damage coupling equation to obtain a dynamic fully coupled lifetime model.

[0020] The evaluation unit is used to evaluate the condition of the traction motor bearing of the high-speed train to be evaluated through the dynamic fully coupled life model, and obtain the remaining life under different operating conditions.

[0021] The beneficial effects of this invention are as follows:

[0022] (1) This invention introduces pressure index and speed index to quantify the exponential effect of material yielding under high pressure and the accelerating effect of temperature rise under high speed, making the wear equation more consistent with actual wear characteristics and avoiding evaluation errors caused by linear assumptions. In view of the complexity of electrochemical corrosion of motor bearings, factors such as current, overvoltage, temperature, and discharge are integrated into the corrosion equation to accurately quantify the nonlinear strengthening effect of each factor on the corrosion rate, and solve the problem of neglecting the coupling of multiple factors in traditional corrosion assessment;

[0023] (2) This invention quantifies the interaction effect of wear and corrosion through a dynamic damage coupling equation, which can characterize the interaction strengthening effect of wear destroying the passivation film and accelerating corrosion, and corrosion producing loose products that aggravate wear, thus avoiding the underestimation of damage caused by wear or corrosion when assessed separately. At the same time, the life decay rate is adjusted differently for different operating conditions such as normal corrosion wear and overvoltage impact, so that the dynamic fully coupled life model can cover the typical operating scenarios of high-speed train bearings, and realize dynamic evaluation of all operating conditions under the consideration of synergistic effects;

[0024] (3) Through the dynamic fully coupled life model, the remaining life under different time and different operating conditions can be directly output, avoiding the limitations of traditional assessments which rely heavily on qualitative judgments and lack quantitative data. Furthermore, based on accurate remaining life assessment, over-maintenance (such as premature replacement of bearings with remaining life) or under-maintenance (such as downtime caused by bearing failure) can be avoided, balancing maintenance costs and operational safety, and providing a scientific basis for the health management of traction motor bearings in high-speed trains.

[0025] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing embodiments of the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the process for assessing the condition of the traction motor bearing of a high-speed train as described in this embodiment of the invention.

[0028] Figure 2 This is a wear depth evolution curve at a fixed bearing speed of 2000 rpm, as shown in the embodiment of the present invention.

[0029] Figure 3 For the embodiment of the present invention, the bearing pressure is fixed at 10. The wear depth evolution curve is shown below.

[0030] Figure 4 This is a schematic diagram of the wear rate curve in an embodiment of the present invention;

[0031] Figure 5 This is a schematic diagram of the wear equation fitting in an embodiment of the present invention;

[0032] Figure 6 This is a corrosion depth evolution curve under constant operating conditions according to an embodiment of the present invention;

[0033] Figure 7 Discharge amount in embodiments of the present invention A schematic diagram of the damage function;

[0034] Figure 8 This is a comparison diagram of corrosion depth under different current levels in an embodiment of the present invention;

[0035] Figure 9 This is a schematic diagram of the corrosion equation fitting in an embodiment of the present invention;

[0036] Figure 10 This is a schematic diagram of dynamic damage decomposition values ​​according to an embodiment of the present invention;

[0037] Figure 11 This is a schematic diagram illustrating the evolution of the lifetime decay function in an embodiment of the present invention;

[0038] Figure 12 This is a schematic diagram of the dynamic fully coupled lifetime model according to an embodiment of the present invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0040] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this invention, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0041] Example 1:

[0042] This embodiment provides a method for assessing the condition of traction motor bearings in high-speed trains.

[0043] See Figure 1 The figure shows that the method includes steps S1, S2, S3, S4, S5 and S6.

[0044] Step S1: Obtain the wear influence parameters and corrosion influence parameters of the traction motor bearing of the high-speed train to be evaluated. The wear influence parameters include bearing pressure, bearing speed, ambient temperature and surface roughness. The corrosion influence parameters include discharge quantity, voltage peak value and corrosion current.

[0045] Step S2: Construct the wear equation for the traction motor bearing of the high-speed train to be evaluated based on the wear influence parameters;

[0046] Step S2 includes:

[0047] Step S21: Based on Achad's wear law, construct the wear volume formula using the wear coefficient and the bearing pressure;

[0048] Understandably, wear is typically associated with surface contact stress. When two object surfaces come into contact, the contact stress between surface micro-protrusions can far exceed their average stress, leading to material removal. According to Akard's law of wear, the wear depth is directly proportional to the actual contact area and inversely proportional to the material hardness.

[0049] By defining a dimensionless wear coefficient, the wear volume formula is obtained as follows:

[0050] ;

[0051] In the formula, Indicates the wear volume. Indicates the wear coefficient. Indicates bearing pressure. Indicates the sliding distance. Indicates the hardness of the material.

[0052] Step S22: Introduce a time dimension into the wear volume formula to obtain a formula for the wear volume change rate with respect to the bearing radius and bearing speed;

[0053] In this step, a time dimension is introduced, and the sliding distance is related to time, thus yielding the formula for the wear volume change rate:

[0054] ;

[0055] In the formula, Indicates the wear volume. Indicates time, Indicates the rate of change of wear volume. Indicates the wear coefficient. Indicates bearing pressure. Indicates the sliding distance. Indicates the hardness of the material. Indicates the bearing radius. Indicates the bearing speed.

[0056] Step S23: Convert the wear volume change rate formula into a wear depth change rate formula based on geometric relationships;

[0057] In this step, the relationship between wear depth and wear volume is as follows:

[0058] ;

[0059] In the formula, Indicates the depth of wear. Indicates the wear volume. Indicates the bearing radius.

[0060] Based on the volume formula, the formula for the rate of change of wear volume is converted into a formula for the rate of change of wear depth:

[0061] ;

[0062] In the formula, Indicates the depth of wear. Indicates time, Indicates the rate of change of wear depth. Indicates the wear coefficient. Indicates bearing pressure. Indicates the bearing speed. Indicates the bearing radius. Indicates the hardness of the material.

[0063] Step S24: Based on the nonlinear characteristics of wear, the wear depth change rate formula is converted into a generalized form of wear depth changing with time, resulting in a wear equation with respect to ambient temperature and surface roughness.

[0064] Understandably, since Archard's wear law is a linear derivation, it only considers the wear rate (rate of change of wear depth) and bearing pressure. and bearing speed The relationship is linear. However, in actual bearing wear, the bearing pressure... and bearing speed The impact on wear is often non-linear. For example, under high pressure, an exponential effect may occur due to material yielding, and at high speeds, wear is accelerated due to temperature rise. Therefore, a pressure exponent is introduced. and speed index Characterizing the nonlinear relationship, we obtain a generalized form of the wear depth variation over time, namely the wear equation:

[0065] ;

[0066] ;

[0067] In the formula, Indicates the rate of change of wear depth. Represents the comprehensive coefficient. Indicates bearing pressure. Indicates the bearing speed. Indicates the stress index. Indicates the speed index. Indicates the wear coefficient. Indicates the bearing radius. Indicates the hardness of the material. This indicates the temperature coefficient of bearing steel. Indicates ambient temperature. This indicates the surface roughness monitored in real time. This indicates the initial surface roughness of the bearing. This indicates the surface roughness correction index.

[0068] in, Indicates the temperature coefficient of hardness. This indicates surface roughness correction, and is applicable to relatively smooth bearings with rolling friction. Take 0.2.

[0069] Step S25: Solve the nonlinear coefficients in the wear equation through experiments. The nonlinear coefficients include the pressure index and the rotational speed index.

[0070] Step S25 includes:

[0071] Step S251: Perform a constant speed variable pressure test on the test sample to obtain the wear amount and wear depth change rate under different bearing pressures;

[0072] Step S252: Conduct a constant pressure and variable speed experiment on the test sample to obtain the wear amount and wear depth change rate under different bearing speeds;

[0073] Step S253: Obtain the pressure index by fitting parameters based on the wear amount and wear depth change rate under different bearing pressures;

[0074] Step S254: Obtain the speed index by fitting parameters based on the wear amount and wear depth change rate under different bearing speeds.

[0075] In this step, due to the rate of change of wear depth and wear volume change rate There are fixed geometric relationships, that is ,therefore It can also be expressed as .because , This represents the experiment duration; substituting it in yields... , This represents the coefficients after integration.

[0076] right Taking the natural logarithm of both sides of the equation transforms the nonlinear relationship into a linear one: .

[0077] In the constant speed variable pressure experiment, the bearing speed fixed, Since is a constant, the above linear equation can be simplified to containing only Linear equations in one variable: ,in, , Represents the first constant term. This is the slope of the linear equation (i.e., the pressure index).

[0078] According to the least squares method, let As the independent variable, Assuming the dependent variable is , we get:

[0079] ;

[0080] In the formula, Indicates the first The bearing pressure in the group experiment This indicates the total number of constant speed variable voltage experiments. Indicates the first Wear volume of the group experiment Indicates the first The duration of the group experiment.

[0081] Similarly, the speed index can be obtained. for:

[0082] ;

[0083] In the formula, Indicates the first The bearing speed in the group experiment, This indicates the total number of groups of constant pressure variable speed experiments. Indicates the first Wear volume of the group experiment Indicates the first The duration of the group experiment.

[0084] Therefore, fitting can be achieved through experimental data. and .

[0085] Step S3: Construct the corrosion equation for the traction motor bearing of the high-speed train to be evaluated based on the corrosion influence parameters;

[0086] It should be noted that the chemical corrosion of motor bearings is primarily driven by electrochemistry, including current, overvoltage, and discharge conditions. It is also temperature-dependent, and therefore can be represented by various sub-items.

[0087] Step S3 includes:

[0088] Step S31: Establish a formula for calculating the mass of corrosion products based on the current effect and perform reverse calculation to obtain the corrosion current;

[0089] In this step, considering the current effect, the formula for calculating the mass of corrosion products is obtained:

[0090] ;

[0091] In the formula, Indicates the quality of corrosion products. This indicates the molar mass of bearing steel. Indicates the number of electrons. Indicates about time Corrosion current.

[0092] By reversing the above formula, the corrosion current can be obtained.

[0093] Step S32: Correct the corrosion current using the voltage peak value to obtain the effective current;

[0094] In this embodiment, a voltage modulation term is constructed to obtain the effective current:

[0095] ;

[0096] In the formula, Indicates the effective current. Indicates corrosion current. Indicates the peak voltage. This represents the voltage modulation coefficient, reflecting the degree to which overvoltage enhances the corrosion current, taking into account the overvoltage situation in high-speed rail. The purpose of setting it to 0.3 is to quantify. The nonlinear enhancement effect on the electrochemical corrosion rate improves the accuracy of condition assessment.

[0097] Step S33: Construct a temperature-reaction rate constant using the ambient temperature;

[0098] In this step, the temperature effect is considered to construct the temperature reaction rate constant:

[0099] ;

[0100] In the formula, Represents the temperature-dependent reaction rate constant. Indicates pre-exponential factor, Represents an exponential function. This represents the activation energy; a typical value for bearing steel is 34.5 kJ / mol. Represents the Boltzmann constant. Indicates ambient temperature.

[0101] Among them, pre-exponential factors This is a precondition constant of the Arrhenius equation, characterizing the effective collision frequency of reactant molecules in the corrosion reaction, and needs to be calibrated through bearing steel corrosion experiments.

[0102] Step S34: Construct the damage function under the cumulative discharge effect using the discharge quantity and discharge damage coefficient;

[0103] In this step, the damage function is constructed considering the cumulative effect of discharge:

[0104] ;

[0105] In the formula, Indicates about the amount of discharge damage function, This represents the discharge damage coefficient, which is 0.009 under normal voltage. For different types of overvoltage, the coefficient is proportionally amplified based on the amount of discharge.

[0106] Step S35: Construct a corrosion equation using the effective current, the temperature reaction rate constant, and the damage function.

[0107] Understandably, we first consider the basic corrosion rate caused by current, then introduce temperature to accelerate corrosion, followed by superimposed discharge damage, and finally introduce the environmental corrosion coefficient to obtain the bearing electro-corrosion rate under the coupled effects of current, overvoltage, and discharge, i.e., the corrosion equation:

[0108] ;

[0109] In the formula, Indicates the degree of corrosion. Indicates time, Indicates the bearing electro-corrosion rate. Indicates about time Corrosion current, Represents the voltage modulation coefficient. Indicates the peak voltage. Indicates pre-exponential factor, Represents an exponential function. Indicates activation energy. Represents the Boltzmann constant. Indicates ambient temperature. Indicates the amount of discharge. Indicates the discharge damage coefficient. This indicates an environmental corrosion system.

[0110] Among these, environmental corrosion is mainly related to environmental humidity, therefore , This represents a typical value for ambient humidity. This represents a typical value for the corrosion resistance of bearing steel, taken as 0.75.

[0111] Step S4: Combining the synergistic effect of wear and corrosion, the wear equation and the corrosion equation are coupled to obtain the dynamic damage coupling equation;

[0112] Understandably, in the actual aging process of traction motor bearings in high-speed trains, mechanical wear and electrochemical corrosion are not independent processes; they exhibit significant time-varying interactions. Specifically, wear damages the passivation film on the bearing surface, increasing the contact area for corrosion reactions and thus accelerating the corrosion process. Simultaneously, corrosion produces porous corrosion products, reducing the bearing surface's wear resistance and, in turn, exacerbating mechanical wear. Therefore, coupled modeling based on their time-varying interaction is necessary to quantify their combined damage effect. In the modeling process, wear depth is used to characterize the bearing's wear level. Combining the previously constructed wear and corrosion equations, and integrating the wear level, corrosion level, and their synergistic effect, a dynamic damage coupling equation is ultimately obtained.

[0113] In step S4, obtaining the dynamic damage coupling equation includes:

[0114] Step S41: Integrate the wear equation over time to obtain an expression for the degree of bearing wear;

[0115] Step S42: Integrate the corrosion equation over time to obtain an expression for the degree of corrosion of the bearing;

[0116] Step S43: Based on the time-varying interaction between wear and corrosion, construct a synergistic effect change rate expression using the wear degree expression and the corrosion degree expression;

[0117] In this embodiment, the expression for the rate of change of the synergistic effect is:

[0118] ;

[0119] In the formula, Indicates the depth of wear. Indicates the degree of corrosion. Indicates time, Indicates the rate of change of the synergistic effect. Indicates the bearing electro-corrosion rate. This indicates the rate of change in wear depth.

[0120] Step S44: Construct a dynamic damage coupling equation based on the wear degree expression, the corrosion degree expression, and the synergistic effect change rate expression.

[0121] In this step, the dynamic damage coupling equation is:

[0122] ;

[0123] In the formula, Indicates about time The dynamic damage coupling value, Indicates the wear-corrosion dominant weight. Indicates about time The degree of wear and tear, Indicates about time The degree of corrosion, Indicates the rate of change of the synergistic effect. This represents the synergy strength coefficient.

[0124] in, It is used to quantify the relative contribution rates of mechanical wear and electrochemical corrosion to bearing damage. It is confirmed to be effective by taking a weighted average of multiple sets of experiments under different working conditions and the dispersion is <5%. The method is used to quantify the interactive reinforcement effect of wear and corrosion, and is obtained through error verification calculations based on multiple sets of wear-corrosion coupled working condition experiments.

[0125] Step S5: Introduce a lifetime decay function into the dynamic damage coupling equation to obtain a dynamic fully coupled lifetime model;

[0126] In this step, a dynamic fully coupled life model is established, focusing on the core principle that damage accumulation accelerates the decay of life over time. By defining the failure coefficient, constructing the decay function, and coupling damage and decay, the actual failure characteristics of the bearing are taken into account.

[0127] In step S5, obtaining the dynamic fully coupled lifetime model includes:

[0128] Step S51: Construct failure coefficients based on different operating conditions;

[0129] In this step, the failure factor These are parameters that quantify the impact of different operating conditions on the bearing life decay rate. For example, under normal corrosion and wear conditions, the bearing is only subjected to conventional mechanical wear and slight electrochemical corrosion (without overvoltage impact), and the life decay is relatively gradual. This indicates that the cumulative effect of damage on lifespan gradually increases over time, consistent with the actual law that wear / corrosion accumulates over time, increasing the risk of failure in later stages. Overvoltage impact conditions refer to extreme situations such as VCB operating overvoltages and lightning strike overvoltages encountered by the bearing. Overvoltages exacerbate discharge damage and electrochemical corrosion, leading to rapid lifespan decay. This indicates that the initial lifespan decay rate is faster (e.g., after a lightning strike, the remaining lifespan of the bearing will drop significantly and drastically). Furthermore... The value is the optimal value verified through multiple sets of working condition experiments, ensuring that the differences in lifespan degradation under different working conditions can be accurately distinguished.

[0130] Step S52: Construct a lifetime decay function based on the theoretical reference time for reaching the critical state and the failure coefficient;

[0131] In this embodiment, the lifetime decay function transforms the time dimension into the degree of lifetime decay. By adjusting the failure coefficient, the lifetime decay curves under different operating conditions can be differentiated. The formula is as follows:

[0132] ;

[0133] In the formula, Indicates about time The lifetime decay function, Represents an exponential function. This represents the theoretical reference time for reaching the critical state. This represents the failure factor under normal corrosion and wear conditions. Considering overvoltage impact .

[0134] Step S53: Multiply the lifetime decay function by the dynamic damage coupling equation to obtain the dynamic fully coupled lifetime model.

[0135] In this embodiment, multiplying the lifetime decay function by the dynamic damage coupling equation effectively corrects real-time damage using the lifetime decay function, yielding a quantified remaining lifetime. The dynamic damage coupling equation then quantifies the bearing's remaining lifetime through wear, corrosion, and synergistic effects. The actual degree of damage at any given time. The dynamic fully coupled lifetime model provides an intuitive quantitative indicator for state assessment. The expression for the dynamic fully coupled lifetime model is:

[0136] ;

[0137] In the formula, Indicates time The remaining life of the bearing, Indicates about time The dynamic damage coupling value, Indicates about time The lifetime decay function.

[0138] Step S6: The condition of the traction motor bearing of the high-speed train to be evaluated is assessed using the dynamic fully coupled life model to obtain the remaining life under different operating conditions.

[0139] In this step, by clarifying the actual operating conditions of the traction motor bearing of the high-speed train to be evaluated (such as operating time, bearing pressure, bearing speed, presence of overvoltage, and ambient temperature), the time is obtained. Time-quantified remaining lifetime.

[0140] Example 2:

[0141] In this embodiment, when constructing the dynamic fully coupled life model of the traction motor bearing of the high-speed train to be evaluated, it is necessary to first prepare the sample of the traction motor bearing of the high-speed train to be evaluated. Then, the initial material parameters of the sample are obtained, including the initial surface roughness. Wear coefficient Sliding distance Bearing radius Molar mass of bearing steel and number of electrons .in, It can be measured directly using a surface roughness tester. The solution can be obtained by performing a standard wear test on the sample and then solving it inversely using Akard's law. The total relative sliding distance between the micro-protrusions on the sample surface and the mating parts during the rolling friction process of the bearing can be calculated using the rotational speed and test duration set on the wear test bench. This is determined by the properties of the bearing itself. The determination is based directly on the conventional corrosion reaction mechanism of bearing steel.

[0142] Constant-speed variable pressure experiments and constant-speed variable pressure experiments were conducted with different experimental durations. In the constant-speed variable pressure experiment, for example, the bearing speed was fixed at 1500 rpm for a certain experimental duration, and the bearing pressure gradient was set to 0. 0.5 5 10 20 and 50 The experimental data are recorded in Table 1.

[0143] Table 1 Experimental data for the constant speed variable voltage experiment

[0144]

[0145] The pressure index was obtained by fitting parameters based on the experimental data from the constant speed pressure variation experiment. .

[0146] When conducting a constant pressure variable speed experiment, for example, fixing the bearing pressure at 5 for a certain experimental duration. The bearing speed gradients were set to 500 rpm, 1000 rpm, 2000 rpm, 3000 rpm and 5000 rpm, and some experimental data were recorded as shown in Table 2.

[0147] Table 2 Experimental data for the constant pressure variable speed experiment

[0148]

[0149] Based on the experimental data from the constant pressure variable speed experiment, parameter fitting was performed to obtain the speed index. .pass and The parameters are calibrated to obtain the corresponding wear equation. For example... Figures 2-6 As shown, this is under conditions of a fixed bearing speed of 2000 rpm and a fixed bearing pressure of 10... The wear depth evolution curve and the fitted wear rate and wear depth curves are used to obtain the corresponding wear equation.

[0150] Then, the corrosion equation is obtained. The corrosion current is calculated by monitoring the mass of corrosion products on the sample over a certain time period. Voltage modulation is then performed, i.e., the effective current is calculated by monitoring the peak voltage during bearing operation, quantifying the nonlinear enhancement effect of overvoltage on the corrosion current. The ambient temperature of the bearing operation is obtained to calculate the temperature response rate constant, characterizing the accelerating effect of temperature on the corrosion reaction rate. Finally, the discharge quantity during bearing operation is monitored to obtain the damage function, thus yielding the corresponding corrosion equation. Figures 7-9 The figure shows the process curve for obtaining the corrosion equation, where the discharge damage factor is the discharge amount. The damage function.

[0151] After obtaining the wear equation and corrosion equation, the parameters in the dynamic damage coupling equation also need to be calibrated. Specifically, 20 sets of working conditions are designed, for example, 5... +1500rpm+VCB operation overvoltage and 5 Operating conditions including +1000rpm and lightning overvoltage. Experimental data were obtained under different conditions, as shown in Table 3.

[0152] Table 3. Partial experimental data under different working conditions

[0153]

[0154] Based on experimental data under multiple operating conditions, Perform a weighted average. Then... Introduction Subsequently, the cooperative strength coefficient was iteratively adjusted through error verification using multiple sets of wear-corrosion coupled operating condition experiments. The values ​​(e.g., gradually testing from 0.1 to 0.5) are compared with different values. The deviation between the theoretically calculated dynamic damage coupling value and the experimentally measured total damage value is used to obtain the value with the smallest error. Value. Finally passed The final value and the constructed lifetime decay function are obtained. .

[0155] like Figures 10-12 As shown ,pass Based on the specific time conditions and parameters of different operating conditions, the quantified remaining life of the traction motor bearing of the high-speed train to be evaluated can be obtained.

[0156] Example 3:

[0157] This embodiment provides a condition assessment system for traction motor bearings of high-speed trains, the system comprising:

[0158] The acquisition unit is used to acquire wear influence parameters and corrosion influence parameters of the traction motor bearing of the high-speed train to be evaluated. The wear influence parameters include bearing pressure, bearing speed, ambient temperature and surface roughness, and the corrosion influence parameters include discharge quantity, voltage peak value and corrosion current.

[0159] The first construction unit is used to construct the wear equation of the traction motor bearing of the high-speed train to be evaluated based on the wear influence parameters.

[0160] The second construction unit is used to construct the corrosion equation of the traction motor bearing of the high-speed train to be evaluated based on the corrosion influence parameters.

[0161] A coupling unit is used to combine the synergistic effects of wear and corrosion, coupling the wear equation and the corrosion equation to obtain a dynamic damage coupling equation;

[0162] An adjustment unit is used to introduce a lifetime decay function into the dynamic damage coupling equation to obtain a dynamic fully coupled lifetime model.

[0163] The evaluation unit is used to evaluate the condition of the traction motor bearing of the high-speed train to be evaluated through the dynamic fully coupled life model, and obtain the remaining life under different operating conditions.

[0164] The first building unit includes:

[0165] The first construction subunit is used to construct a wear volume formula based on the Achad wear law, using the wear coefficient and the bearing pressure;

[0166] The second construction subunit is used to introduce a time dimension into the wear volume formula to obtain a formula for the wear volume change rate with respect to the bearing radius and bearing speed.

[0167] The first conversion subunit is used to convert the wear volume change rate formula into the wear depth change rate formula based on geometric relationships.

[0168] The second transformation subunit is used to convert the wear depth change rate formula into a generalized form of wear depth changing with time based on the nonlinear characteristics of wear, so as to obtain the wear equation with respect to ambient temperature and surface roughness.

[0169] The solution sub-unit is used to experimentally solve the nonlinear coefficients in the wear equation, including the pressure exponent and the rotational speed exponent.

[0170] The second building unit includes:

[0171] The calculation subunit is used to establish a formula for calculating the mass of corrosion products based on the current effect and to perform inverse calculation to obtain the corrosion current.

[0172] A correction subunit is used to correct the corrosion current based on the voltage peak value to obtain an effective current;

[0173] The third building subunit is used to build a temperature reaction rate constant based on the ambient temperature;

[0174] The fourth sub-unit is used to construct the damage function under the cumulative discharge effect by means of discharge quantity and discharge damage coefficient;

[0175] The fifth construction subunit is used to construct the corrosion equation using the effective current, the temperature reaction rate constant, and the damage function.

[0176] The coupling unit includes:

[0177] The first integrator subunit is used to perform time integration on the wear equation to obtain an expression for the wear degree of the bearing;

[0178] The second integrator is used to perform time integration on the corrosion equation to obtain an expression for the degree of corrosion of the bearing.

[0179] The sixth sub-unit is used to construct a synergistic effect change rate expression based on the time-varying interaction between wear and corrosion, using the wear degree expression and the corrosion degree expression.

[0180] The seventh construction subunit is used to construct a dynamic damage coupling equation based on the wear degree expression, the corrosion degree expression, and the synergistic effect change rate expression.

[0181] The adjustment unit includes:

[0182] The eighth sub-unit is used to construct failure coefficients based on different operating conditions;

[0183] The ninth construction subunit is used to construct a lifetime decay function based on the theoretical reference time for reaching the critical state and the failure coefficient;

[0184] The tenth sub-unit is used to multiply the lifetime decay function with the dynamic damage coupling equation to obtain a dynamic fully coupled lifetime model.

[0185] It should be noted that the specific methods by which each module performs operations in the system described in the above embodiments have been described in detail in the embodiments related to the method, and will not be elaborated here.

[0186] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0187] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for evaluating the state of a high-speed EMU traction motor bearing, characterized in that, include: The wear and corrosion impact parameters of the traction motor bearing of the high-speed train to be evaluated are obtained. The wear impact parameters include bearing pressure, bearing speed, ambient temperature and surface roughness. The corrosion impact parameters include discharge quantity, peak voltage and corrosion current. Based on the wear influence parameters, a wear equation for the traction motor bearing of the high-speed train to be evaluated is constructed; The corrosion equation for the bearing of the traction motor of the high-speed train to be evaluated is constructed based on the corrosion influence parameters. By combining the synergistic effects of wear and corrosion, the wear equation and the corrosion equation are coupled to obtain a dynamic damage coupling equation; By introducing a lifetime decay function into the dynamic damage coupling equation, a dynamic fully coupled lifetime model is obtained. The dynamic fully coupled life model is used to evaluate the condition of the traction motor bearing of the high-speed train under evaluation and obtain the remaining life under different operating conditions. The wear equation is: ； ； wherein, represents the wear depth, represents time, represents the wear depth change rate, represents the comprehensive coefficient, represents the bearing pressure, represents the bearing rotational speed, represents the pressure index, represents the rotational speed index, represents the wear coefficient, represents the bearing radius, represents the material hardness, represents the temperature coefficient of the bearing steel, represents the ambient temperature, represents the real-time monitored surface roughness, represents the initial surface roughness of the bearing, represents the surface roughness correction index; The corrosion equation is as follows: ； In the formula, Indicates the degree of corrosion. Indicates time, Indicates the bearing electro-corrosion rate. Indicates about time Corrosion current, Represents the voltage modulation coefficient. Indicates the peak voltage. Indicates pre-exponential factor, Represents an exponential function. Indicates activation energy. Represents the Boltzmann constant. Indicates ambient temperature. Indicates the amount of discharge. Indicates the discharge damage coefficient. Indicates an environmental corrosion system; The dynamic damage coupling equation is: ； In the formula, Indicates about time The dynamic damage coupling value, Indicates the wear-corrosion dominant weight. Indicates about time The degree of wear and tear, Indicates about time The degree of corrosion, Indicates the rate of change of the synergistic effect. This represents the synergy strength coefficient.

2. The method for assessing the condition of traction motor bearings in high-speed trains according to claim 1, characterized in that... The step of constructing the wear equation for the traction motor bearing of the high-speed train to be evaluated based on the wear influence parameters includes: Based on Achad's wear law, a wear volume formula is constructed using the wear coefficient and the bearing pressure. By introducing a time dimension into the wear volume formula, a formula for the wear volume change rate with respect to the bearing radius and bearing speed is obtained; Based on geometric relationships, the formula for the rate of change of wear volume is converted into a formula for the rate of change of wear depth. Based on the nonlinear characteristics of wear, the formula for the rate of change of wear depth is transformed into a generalized form of wear depth changing with time, resulting in a wear equation for ambient temperature and surface roughness. The nonlinear coefficients in the wear equation are determined experimentally. These nonlinear coefficients include the pressure index and the rotational speed index.

3. The method for assessing the condition of traction motor bearings in high-speed trains according to claim 1, characterized in that... The step of constructing the corrosion equation for the traction motor bearing of the high-speed train to be evaluated based on the corrosion influence parameters includes: A formula for calculating the mass of corrosion products was established based on the current effect and then solved in reverse to obtain the corrosion current. The corrosion current is corrected by the voltage peak value to obtain the effective current; The temperature-reaction rate constant is constructed using the ambient temperature. A damage function under the cumulative discharge effect is constructed by using discharge quantity and discharge damage coefficient; A corrosion equation is constructed using the effective current, the temperature-reaction rate constant, and the damage function.

4. The condition assessment method for traction motor bearings of high-speed trains according to claim 1, characterized in that... The obtained dynamic damage coupling equation includes: By integrating the wear equation over time, an expression for the degree of bearing wear is obtained; By integrating the corrosion equation over time, an expression for the degree of corrosion of the bearing is obtained; Based on the time-varying interaction between wear and corrosion, a synergistic effect change rate expression is constructed using the wear degree expression and the corrosion degree expression; A dynamic damage coupling equation is constructed based on the wear degree expression, the corrosion degree expression, and the synergistic effect change rate expression.

5. The method for assessing the condition of traction motor bearings in high-speed trains according to claim 1, characterized in that... The obtained dynamic fully coupled lifetime model includes: Failure coefficients are constructed based on different operating conditions; A lifetime decay function is constructed based on the theoretical reference time for reaching the critical state and the failure coefficient. Multiplying the lifetime decay function by the dynamic damage coupling equation yields the dynamic fully coupled lifetime model.

6. A condition assessment system for traction motor bearings of high-speed trains, characterized in that, include: The acquisition unit is used to acquire wear influence parameters and corrosion influence parameters of the traction motor bearing of the high-speed train to be evaluated. The wear influence parameters include bearing pressure, bearing speed, ambient temperature and surface roughness, and the corrosion influence parameters include discharge quantity, voltage peak value and corrosion current. The first construction unit is used to construct the wear equation of the traction motor bearing of the high-speed train to be evaluated based on the wear influence parameters. The second construction unit is used to construct the corrosion equation of the traction motor bearing of the high-speed train to be evaluated based on the corrosion influence parameters. A coupling unit is used to combine the synergistic effects of wear and corrosion, coupling the wear equation and the corrosion equation to obtain a dynamic damage coupling equation; An adjustment unit is used to introduce a lifetime decay function into the dynamic damage coupling equation to obtain a dynamic fully coupled lifetime model. The evaluation unit is used to evaluate the condition of the traction motor bearing of the high-speed train to be evaluated through the dynamic fully coupled life model, and obtain the remaining life under different working conditions. The wear equation is: ； ； In the formula, Indicates the depth of wear. Indicates time, Indicates the rate of change of wear depth. Represents the comprehensive coefficient. Indicates bearing pressure. Indicates the bearing speed. Indicates the stress index. Indicates the speed index. Indicates the wear coefficient. Indicates the bearing radius. Indicates the hardness of the material. This indicates the temperature coefficient of bearing steel. Indicates ambient temperature. This indicates the surface roughness monitored in real time. This indicates the initial surface roughness of the bearing. Indicates the surface roughness correction index; The corrosion equation is as follows: ； In the formula, Indicates the degree of corrosion. Indicates time, Indicates the bearing electro-corrosion rate. Indicates about time Corrosion current, Represents the voltage modulation coefficient. Indicates the peak voltage. Indicates pre-exponential factor, Represents an exponential function. Indicates activation energy. Represents the Boltzmann constant. Indicates ambient temperature. Indicates the amount of discharge. Indicates the discharge damage coefficient. Indicates an environmental corrosion system; The dynamic damage coupling equation is: ； In the formula, Indicates about time The dynamic damage coupling value, Indicates the wear-corrosion dominant weight. Indicates about time The degree of wear and tear, Indicates about time The degree of corrosion, Indicates the rate of change of the synergistic effect. This represents the synergy strength coefficient.

7. The condition assessment system for traction motor bearings of high-speed trains according to claim 6, characterized in that, The first building unit includes: The first construction subunit is used to construct a wear volume formula based on the Achad wear law, using the wear coefficient and the bearing pressure; The second construction subunit is used to introduce a time dimension into the wear volume formula to obtain a formula for the wear volume change rate with respect to the bearing radius and bearing speed. The first conversion subunit is used to convert the wear volume change rate formula into the wear depth change rate formula based on geometric relationships. The second transformation subunit is used to convert the wear depth change rate formula into a generalized form of wear depth changing with time based on the nonlinear characteristics of wear, so as to obtain the wear equation with respect to ambient temperature and surface roughness. The solution sub-unit is used to experimentally solve the nonlinear coefficients in the wear equation, including the pressure exponent and the rotational speed exponent.

8. The condition assessment system for traction motor bearings of high-speed trains according to claim 6, characterized in that, The second building unit includes: The calculation subunit is used to establish a formula for calculating the mass of corrosion products based on the current effect and to perform inverse calculation to obtain the corrosion current. A correction subunit is used to correct the corrosion current based on the voltage peak value to obtain an effective current; The third building subunit is used to build a temperature reaction rate constant based on the ambient temperature; The fourth sub-unit is used to construct the damage function under the cumulative discharge effect by means of discharge quantity and discharge damage coefficient; The fifth construction subunit is used to construct the corrosion equation using the effective current, the temperature reaction rate constant, and the damage function.

9. The condition assessment system for traction motor bearings of high-speed trains according to claim 6, characterized in that, The coupling unit includes: The first integrator subunit is used to perform time integration on the wear equation to obtain an expression for the wear degree of the bearing; The second integrator is used to perform time integration on the corrosion equation to obtain an expression for the degree of corrosion of the bearing. The sixth sub-unit is used to construct a synergistic effect change rate expression based on the time-varying interaction between wear and corrosion, using the wear degree expression and the corrosion degree expression. The seventh construction subunit is used to construct a dynamic damage coupling equation based on the wear degree expression, the corrosion degree expression, and the synergistic effect change rate expression.

10. The condition assessment system for traction motor bearings of high-speed trains according to claim 6, characterized in that, The adjustment unit includes: The eighth sub-unit is used to construct failure coefficients based on different operating conditions; The ninth construction subunit is used to construct a lifetime decay function based on the theoretical reference time for reaching the critical state and the failure coefficient; The tenth sub-unit is used to multiply the lifetime decay function with the dynamic damage coupling equation to obtain a dynamic fully coupled lifetime model.

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