Method and system for selecting lubricating oil for an oil-cooled electric drive integrated system

Abstract

The embodiment of the application provides a kind of oil cooling electric drive integrated system lubricating oil selection method and system, belong to transmission field.The method comprises: obtaining each operating parameter of oil cooling electric drive integrated system;Each operating parameter is input to the lubricating oil target calculation model constructed in advance, obtains each performance parameter target value of oil cooling electric drive integrated system standard lubricating oil, selects the lubricating oil to be selected to carry out each performance test test, obtains each performance parameter test value;Each performance parameter test value is compared with each performance parameter target value, if it meets preset condition, then use the lubricating oil to be selected as oil cooling electric drive integrated system lubricating oil.According to each operating parameter of oil cooling power drive integrated system, it can be considered from multiple factors when selecting lubricating oil, which improves the adaptability of lubricating oil to some extent, and by combining the constructed lubricating oil target calculation model, it can more accurately select lubricating oil.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of transmission, in particular to a selection method and system of lubricating oil for an oil-cooled electric drive integrated system. BACKGROUND

[0002] With the marketization of new energy vehicles, the electric drive system has also been greatly developed, and various electric drive systems have appeared one after another. The scheme of oil-cooled motor integrated gearbox is the main development trend. Lubricating oil is the "blood system" of the transmission system, which undertakes the functions of lubrication, cooling, cleaning, dispersion, rust prevention and vibration reduction. The development of the oil-cooled electric drive integrated system puts forward new requirements and challenges for the lubricating oil of the transmission system, and major oil product manufacturers have also successively launched lubricating oil products for oil-cooled electric drive systems. How to select the lubricating oil product suitable for a specific oil-cooled electric drive integrated system has become a difficult problem for application engineers of major host manufacturers.

[0003] At present, the existing technology mainly carries out application selection research on the influence of lubricating oil on the reliability and efficiency performance of the transmission system, and selects the lubricating oil through the calculation of gear contact strength and gear oil stirring loss. When it is applied to the oil-cooled electric drive integrated system, the considered factors are relatively single, which leads to the inability to accurately select the lubricating oil suitable for the oil-cooled electric drive integrated system. SUMMARY

[0004] The purpose of the embodiments of the present application is to provide a selection method and system of lubricating oil for an oil-cooled electric drive integrated system, which is used to solve at least partially the technical problem that the considered factors are relatively single in the existing technology, leading to the inability to accurately select the lubricating oil suitable for the oil-cooled electric drive integrated system.

[0005] In order to achieve the above-mentioned purpose, the embodiments of the present application provide a selection method of lubricating oil for an oil-cooled electric drive integrated system, comprising:

[0006] obtaining various operating parameters of the oil-cooled electric drive integrated system;

[0007] inputting the various operating parameters into a pre-constructed lubricating oil target calculation model to obtain various performance parameter target values of the standard lubricating oil for the oil-cooled electric drive integrated system, wherein the lubricating oil target calculation model is integrated with various performance calculation sub-models of the lubricating oil;

[0008] selecting the lubricating oil to be selected to perform various performance test experiments to obtain various performance parameter test values;

[0009] comparing the various performance parameter test values with the various performance parameter target values, and if a preset condition is met, selecting the lubricating oil to be selected as the lubricating oil for the oil-cooled electric drive integrated system.

[0010] Optionally, the operation parameters of the oil-cooled electric drive integrated system include: a gear face contact stress, an input rotating speed, an oil cooler cooling water temperature, a motor voltage, and a motor operating temperature of the oil-cooled electric drive integrated system.

[0011] The performance parameters of the lubricating oil include an anti-wear performance parameter, a shear stability performance parameter, an oxidation stability performance parameter, a breakdown voltage performance parameter, and a thermal conductivity performance parameter.

[0012] Optionally, the operation parameters are input into a pre-constructed lubricating oil target calculation model to obtain target values of the performance parameters of the standard lubricating oil of the oil-cooled electric drive integrated system, including:

[0013] The upper limit value of the gear face contact stress is input into an anti-wear calculation sub-model of the lubricating oil to determine a FZG gear bond test grade, which is taken as the anti-wear performance parameter target value.

[0014] The upper limit value of the rotating speed is input into a shear stability calculation sub-model of the lubricating oil to determine an upper limit value of a decrease in the kinematic viscosity of the lubricating oil at a set temperature after a KRL shear stability test, which is taken as the shear stability performance parameter target value.

[0015] The upper limit value of the oil cooler cooling water temperature is input into an oxidation stability calculation sub-model to determine an upper limit value of the acid value change rate of the lubricating oil after a DKA oxidation stability test, which is taken as the oxidation stability performance parameter target value.

[0016] The upper limit value of the motor voltage is input into a breakdown voltage calculation sub-model to determine a lower limit value of the breakdown voltage of the lubricating oil, which is taken as the breakdown voltage performance parameter target value.

[0017] The upper limit value of the motor operating temperature is input into a thermal conductivity calculation sub-model to determine a lower limit value of the thermal conductivity of the lubricating oil, which is taken as the thermal conductivity performance parameter target value.

[0018] Optionally, the construction of the anti-wear calculation sub-model of the lubricating oil includes:

[0019] Based on the FZG gear bond test grade, the upper limit value of the gear face contact stress, and an anti-wear influence coefficient, an anti-wear calculation sub-model of the lubricating oil is constructed, wherein the FZG gear bond test grade is directly proportional to the upper limit value of the gear face contact stress and the anti-wear influence coefficient.

[0020] Optionally, the construction of the shear stability calculation sub-model of the lubricating oil includes:

[0021] Based on the viscosity drop of the lubricating oil under the movement at the set temperature, the upper limit value of the rotation speed and the shear stability influence coefficient after the KRL shear stability test, a shear stability calculation sub-model of the lubricating oil is constructed, wherein the viscosity drop of the lubricating oil under the movement at the set temperature is proportional to the upper limit value of the rotation speed and the shear stability influence coefficient after the KRL shear stability test.

[0022] Optionally, the construction of the oxidation stability calculation sub-model comprises:

[0023] Based on the acid value change of the lubricating oil after the DKA oxidation stability test, the upper limit value of the oil cooler cooling water temperature and the oxidation stability influence coefficient, an oxidation stability calculation sub-model is constructed, wherein the acid value change of the lubricating oil after the DKA oxidation stability test is proportional to the upper limit value of the oil cooler cooling water temperature and the oxidation stability influence coefficient.

[0024] Optionally, the construction of the breakdown voltage calculation sub-model comprises:

[0025] Based on the breakdown voltage of the lubricating oil, the upper limit value of the motor voltage and the breakdown voltage influence coefficient, a breakdown voltage calculation sub-model is constructed, wherein the breakdown voltage of the lubricating oil is proportional to the upper limit value of the motor voltage and the breakdown voltage influence coefficient.

[0026] Optionally, the construction of the thermal conductivity calculation sub-model comprises:

[0027] Based on the thermal conductivity of the lubricating oil, the upper limit value of the motor operating temperature and the thermal conductivity influence coefficient, a thermal conductivity calculation sub-model is constructed, wherein the thermal conductivity of the lubricating oil is proportional to the upper limit value of the motor operating temperature and the thermal conductivity influence coefficient.

[0028] Optionally, the performance parameter test values are compared with the performance parameter target values, and if a preset condition is met, the lubricating oil to be selected is selected as the oil-cooled electric drive integrated system lubricating oil, comprising:

[0029] If at least three of the anti-wear performance parameter test value, the shear stability performance parameter test value, the oxidation stability performance parameter test value, the breakdown voltage performance parameter test value and the thermal conductivity performance parameter test value of the lubricating oil to be selected meet the corresponding performance parameter target value, the lubricating oil to be selected is selected as the oil-cooled electric drive integrated system lubricating oil.

[0030] In another aspect, the application also provides an oil-cooled electric drive integrated system lubricating oil selection system, comprising:

[0031] An acquisition unit is configured to acquire various operating parameters of the oil-cooled electric drive integrated system.

[0032] a calculation unit configured to input the operating parameters into a pre-constructed lubricating oil target calculation model to obtain target values of performance parameters of the lubricating oil of the oil-cooled electric drive integrated system, wherein the lubricating oil target calculation model is integrated with a lubricating oil performance calculation sub-model;

[0033] a test unit configured to select the lubricating oil to be selected to perform performance test to obtain test values of the performance parameters;

[0034] a judgment unit configured to compare the test values of the performance parameters with the target values of the performance parameters, and if a preset condition is met, select the lubricating oil to be selected as the lubricating oil of the oil-cooled electric drive integrated system.

[0035] Through the above technical solution, the operating parameters of the oil-cooled electric drive integrated system are used to consider multiple factors when selecting the lubricating oil, which improves the adaptability of the lubricating oil to a certain extent, and the lubricating oil is selected more accurately by combining the lubricating oil target calculation model, which further realizes the performance quantization selection of the lubricating oil based on the working parameters and performance requirements of the oil-cooled electric drive integrated system, provides a basis for the selection of the lubricating oil, and improves the selection accuracy.

[0036] Other features and advantages of the embodiments of the present application will be described in detail in the following specific implementation part. BRIEF DESCRIPTION OF DRAWINGS

[0037] The accompanying drawings are included to provide a further understanding of the embodiments of the present application, and constitute a part of the specification, and are used to explain the embodiments of the present application together with the following specific implementation, but do not constitute a limitation of the embodiments of the present application. In the drawings:

[0038] Figure 1 is an implementation flowchart of the lubricating oil selection method of the oil-cooled electric drive integrated system provided by the embodiments of the present application;

[0039] Figure 2 is a detailed implementation flowchart of the lubricating oil selection method of the oil-cooled electric drive integrated system provided by the embodiments of the present application;

[0040] Figure 3 is a structural schematic diagram of the lubricating oil selection system of the oil-cooled electric drive integrated system provided by the embodiments of the present application. DETAILED DESCRIPTION

[0041] The specific implementation of the embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the embodiments of the present application, and is not used to limit the embodiments of the present application.

[0042] The basic principle of the oil cooling electric drive integrated system lubricating oil selection method is as follows: the anti-wear requirement of the lubricating oil mainly depends on the tooth surface contact stress, the greater the tooth surface contact stress, the more serious the gear wear, and the higher the anti-wear requirement; the shear stability requirement of the lubricating oil mainly depends on the input rotating speed, the higher the input rotating speed, the more severe the lubricating oil shear, and the higher the shear stability requirement; the oxidation stability requirement of the lubricating oil mainly depends on the oil cooler cooling water temperature, the higher the cooling water temperature, the worse the cooling effect of the lubricating oil, and the higher the oxidation stability requirement; the breakdown voltage of the lubricating oil mainly depends on the motor voltage, the higher the motor voltage, the greater the risk of the breakdown of the lubricating oil, and the higher the breakdown voltage requirement; and the thermal conductivity of the lubricating oil mainly depends on the motor working temperature, the higher the motor working temperature, the greater the requirement for the speed of the lubricating oil in conducting heat, and the higher the thermal conductivity requirement.

[0043] Specifically, the oil cooling electric drive integrated system lubricating oil selection method determines the anti-wear, shear stability, oxidation stability, breakdown voltage and thermal conductivity targets of the lubricating oil based on the maximum tooth surface contact stress, the maximum input rotating speed, the highest oil cooler cooling water temperature, the maximum motor voltage and the maximum motor working temperature of the oil cooling electric drive integrated system, realizes the quantitative selection of the lubricating oil performance based on the working parameters and performance requirements of the oil cooling electric drive integrated system, and provides a basis for the selection of the lubricating oil.

[0044] Referring to Figure 1 FIG. 1 is an implementation flowchart of the oil cooling electric drive integrated system lubricating oil selection method provided by the embodiment of the present application, which includes the following execution steps:

[0045] Step 100: Obtain various operating parameters of the oil cooling electric drive integrated system.

[0046] Specifically, the various operating parameters of the oil cooling electric drive integrated system include the tooth surface contact stress, the input rotating speed, the oil cooler cooling water temperature, the motor voltage and the motor working temperature of the oil cooling electric drive integrated system.

[0047] Preferably, the various operating parameters of the oil cooling electric drive integrated system include the maximum tooth surface contact stress, the maximum input rotating speed, the highest oil cooler cooling water temperature, the maximum motor voltage and the maximum motor working temperature of the oil cooling electric drive integrated system.

[0048] In some embodiments, the relevant information of a certain oil cooling electric drive integrated system is shown in Table 1:

[0049] Table 1 Relevant information of a certain oil cooling electric drive integrated system

[0050]

[0051] Step 101: inputting the operating parameters into a pre-constructed lubricating oil target calculation model to obtain performance parameter target values of the oil-cooled electric drive integrated system standard lubricating oil.

[0052] The lubricating oil target calculation model is integrated with a lubricating oil performance calculation sub-model.

[0053] Preferably, the performance parameters of the lubricating oil include anti-wear performance parameters, shear stability performance parameters, oxidation stability performance parameters, breakdown voltage performance parameters, and thermal conductivity performance parameters.

[0054] In some embodiments, when step 101 is performed, the following steps can be specifically performed:

[0055] S1010: inputting the upper limit value of the tooth surface contact stress into the lubricating oil anti-wear calculation sub-model to determine the FZG gear bond test grade, and taking it as the anti-wear parameter target value.

[0056] Specifically, the construction of the lubricating oil anti-wear calculation sub-model includes: based on the FZG gear bond test grade, the upper limit value of the tooth surface contact stress, and the anti-wear influence coefficient, constructing the lubricating oil anti-wear calculation sub-model, wherein the FZG gear bond test grade is directly proportional to the upper limit value of the tooth surface contact stress and the anti-wear influence coefficient.

[0057] Preferably, the FZG gear bond test grade is determined according to the maximum value of the tooth surface contact stress as the anti-wear target, which is quantitatively objective.

[0058] Further, the lubricating oil anti-wear target model is as follows:

[0059]

[0060] In the formula, represents the FZG gear bond test grade, represents the maximum value of the tooth surface contact stress, and the unit is , represents the anti-wear influence coefficient.

[0061] Preferably, the FZG gear bond test is based on the Chinese Petroleum Chemical Industry Standard NB / SH / T0306, the test condition is A10 / 16.6R / 90, and the anti-wear influence coefficient is .

[0062] S1011: inputting the upper limit value of the rotational speed into the lubricating oil shear stability calculation sub-model to determine the upper limit value of the lubricating oil kinematic viscosity drop at a set temperature after KRL shear stability test, and taking it as the shear stability parameter target value.

[0063] Specifically, the construction of the lubricating oil shear stability calculation sub-model comprises: based on the viscosity reduction of the lubricating oil under a set temperature movement after the KRL shear stability test, the upper limit of the rotation speed and the shear stability influence coefficient, the lubricating oil shear stability calculation sub-model is constructed, wherein the viscosity reduction of the lubricating oil under the set temperature movement after the KRL shear stability test is proportional to the upper limit of the rotation speed and the shear stability influence coefficient.

[0064] Preferably, the maximum value of the 100℃ kinematic viscosity reduction of the lubricating oil after the KRL shear stability test is determined according to the maximum input rotation speed, as the shear stability target, which is quantified objectively.

[0065] Further, the lubricating oil shear stability target model is shown as follows:

[0066]

[0067] In the formula, represents the 100℃ kinematic viscosity reduction of the lubricating oil after the KRL shear stability test, in %, o represents a constant term, represents the maximum input rotation speed, in r / min, represents the shear stability influence coefficient.

[0068] Preferably, the KRL shear stability test is based on the Chinese Petroleum Chemical Industry Standard NB / SH / T0845, the test condition is 60℃, 20h, the constant term is 25, and the shear stability influence coefficient is 1 / 800.

[0069] S1012: input the upper limit of the oil cooler cooling water temperature to the oxidation stability calculation sub-model, determine the upper limit of the acid value change rate of the lubricating oil after the DKA oxidation stability test, and take it as the oxidation stability parameter target value.

[0070] Specifically, the construction of the oxidation stability calculation sub-model comprises: based on the acid value change of the lubricating oil after the DKA oxidation stability test, the upper limit of the oil cooler cooling water temperature and the oxidation stability influence coefficient, the oxidation stability calculation sub-model is constructed, wherein the acid value change of the lubricating oil after the DKA oxidation stability test is proportional to the upper limit of the oil cooler cooling water temperature and the oxidation stability influence coefficient.

[0071] Preferably, the maximum value of the acid value change rate of the lubricating oil after the DKA oxidation stability test is determined according to the maximum value of the oil cooler cooling water temperature, as the oxidation stability target, which is quantified objectively.

[0072] Further, the oxidation stability target model is shown as follows:

[0073]

[0074] wherein, represents the change of acid value of lubricating oil after DKA oxidation stability test (in terms of KOH), unit: mg / g, o represents a constant term, represents the maximum value of oil cooler cooling water temperature, unit: ℃, represents the oxidation stability influence coefficient.

[0075] Preferably, the DKA oxidation stability test is according to the Chinese Petroleum Chemical Industry Standard NB / SH / T6049, the test condition is 160℃, 192h, the constant term is 30, and the oxidation stability influence coefficient is 1 / 3.

[0076] S1013: input the motor voltage upper limit value into the breakdown voltage calculation sub-model, determine the lower limit value of the breakdown voltage of the lubricating oil, and take it as the breakdown voltage parameter target value.

[0077] Specifically, the construction of the breakdown voltage calculation sub-model includes: based on the breakdown voltage of the lubricating oil, the motor voltage upper limit value and the breakdown voltage influence coefficient, the breakdown voltage calculation sub-model is constructed, wherein the breakdown voltage of the lubricating oil is proportional to the motor voltage upper limit value and the breakdown voltage influence coefficient.

[0078] Preferably, the minimum value of the breakdown voltage of the lubricating oil is determined according to the maximum value of the motor voltage, as the breakdown voltage target, the process is quantified objectively.

[0079] Further, the breakdown voltage target model is as follows:

[0080]

[0081] wherein, represents the breakdown voltage of the lubricating oil, unit: kV, represents the maximum value of the motor voltage, unit: V, represents the breakdown voltage influence coefficient.

[0082] Preferably, the breakdown voltage test is according to the Chinese National Standard GB / T507, the test condition is room temperature, and the breakdown voltage influence coefficient is 1 / 10.

[0083] S1014: input the motor working temperature upper limit value into the thermal conductivity calculation sub-model, determine the lower limit value of the thermal conductivity of the lubricating oil, and take it as the thermal conductivity parameter target value.

[0084] Specifically, the construction of the thermal conductivity calculation sub-model comprises: constructing the thermal conductivity calculation sub-model based on the thermal conductivity of the lubricating oil, the upper limit of the motor operating temperature, and the thermal conductivity influence coefficient, wherein the thermal conductivity of the lubricating oil is directly proportional to the upper limit of the motor operating temperature and the thermal conductivity influence coefficient.

[0085] Preferably, the minimum value of the thermal conductivity of the lubricating oil is determined according to the maximum value of the motor operating temperature as the thermal conductivity target, and the process is quantified objectively.

[0086] Further, the thermal conductivity target model is as follows:

[0087]

[0088] In the formula, represents the thermal conductivity of the lubricating oil, with the unit of w / m*k, represents the maximum value of the motor operating temperature, with the unit of ℃, represents the thermal conductivity influence coefficient.

[0089] Preferably, the thermal conductivity test is performed according to the American Society for Testing Materials standard ASTM D7896, the test condition is 80℃, and the thermal conductivity influence coefficient is 1 / 1000.

[0090] In some embodiments, each parameter in Table 1 is respectively brought into the above-mentioned lubricating oil performance calculation sub-model, and the target values of each performance parameter are shown in Table 2:

[0091] Table 2 Target values of each performance parameter

[0092]

[0093] Step 102: Selecting the lubricating oil to be selected to perform each performance test to obtain the test values of each performance parameter.

[0094] In the specific implementation process, the anti-wear test result is performed according to the FZG gear adhesion test specified in the Chinese Petroleum and Chemical Industry Standard NB / SH / T0306, the test condition is A10 / 16.6R / 90; the shear stability test result is performed according to the KRL shear stability test specified in the Chinese Petroleum and Chemical Industry Standard NB / SH / T0845, the test condition is 60℃, 20h; the oxidation stability test result is performed according to the DKA oxidation stability test specified in the Chinese Petroleum and Chemical Industry Standard NB / SH / T6049, the test condition is 160℃, 192h; the breakdown voltage test result is performed according to the breakdown voltage test specified in the Chinese National Standard GB / T 507, the test condition is room temperature; and the thermal conductivity test result is performed according to the thermal conductivity test specified in the American Society for Testing Materials standard ASTM D7896, the test condition is 80℃.

[0095] Specifically, the specific test results of a certain lubricating oil are shown in Table 3.

[0096] Table 3 Specific test results of a certain lubricating oil

[0097]

[0098] Step 103: Comparing the performance parameter test values with the target values of the performance parameters, if the preset condition is met, the lubricating oil to be selected is selected as the lubricating oil of the oil-cooled electric drive integrated system.

[0099] In some embodiments, when step 103 is performed, the following steps can be specifically performed: if at least three of the anti-wear performance parameter test value, the shear stability performance parameter test value, the oxidation stability performance parameter test value, the breakdown voltage performance parameter test value and the thermal conductivity performance parameter test value of the lubricating oil to be selected meet the corresponding target values of the performance parameters, the lubricating oil to be selected is selected as the lubricating oil of the oil-cooled electric drive integrated system.

[0100] Specifically, the comparison results of the experimental results and the target values are shown in Table 4.

[0101] Table 4 Comparison results of experimental results and target values

[0102]

[0103] As shown in Table 4, the shear stability test result less than the target value indicates that it meets the requirement, the oxidation stability test result less than the target value indicates that it meets the requirement, the anti-wear test result greater than or equal to the target value indicates that it meets the requirement, the breakdown voltage test result greater than or equal to the target value indicates that it meets the requirement, and the thermal conductivity test result greater than or equal to the target value indicates that it meets the requirement.

[0104] Preferably, when the anti-wear property, the shear stability, the oxidation stability, the breakdown voltage and the thermal conductivity of the lubricating oil all meet the requirements, the lubricating oil can be used as the lubricating oil of the oil-cooled electric drive system, which provides a basis for selecting the lubricating oil of the oil-cooled electric drive integrated system.

[0105] Referring to Figure 2 Fig. 1 shows a detailed implementation flowchart of a selection method of a lubricating oil of an oil-cooled electric drive integrated system provided by an embodiment of the present application, which includes the following execution steps:

[0106] S200: Obtaining the maximum value of the gear surface contact stress, the maximum value of the input rotation speed, the maximum value of the cooling water temperature of the oil cooler, the maximum value of the motor voltage and the maximum value of the motor working temperature of the oil-cooled electric drive integrated system.

[0107] S201: Establish a lubricating oil anti-wear, shear stability, oxidation stability, breakdown voltage and thermal conductivity target calculation model.

[0108] S202: Calculate the anti-wear, shear stability, oxidation stability, breakdown voltage and thermal conductivity target values of the stable lubricating oil.

[0109] S203: Obtain the anti-wear, shear stability, oxidation stability, breakdown voltage and thermal conductivity test results of a certain lubricating oil.

[0110] S204: Determine whether the lubricating oil test results meet the calculated target values of each item. If yes, execute step S205, otherwise, continue to execute step S203.

[0111] S205: Select the lubricating oil as the oil-cooled electric drive integrated system lubricating oil.

[0112] The oil-cooled electric drive integrated system lubricating oil selection method provided by the present application can quantitatively determine the characteristics target of the lubricating oil according to the system parameters of the oil-cooled electric drive, and the determination process is more objective, providing a basis for the selection of the oil-cooled electric drive integrated system lubricating oil.

[0113] Referring to Figure 3 The structure of the oil-cooled electric drive integrated system lubricating oil selection system provided by the embodiment of the present application is shown in the figure, which includes:

[0114] The acquisition unit 300 is used to acquire various operating parameters of the oil-cooled electric drive integrated system;

[0115] The calculation unit 301 is used to input the various operating parameters into a pre-constructed lubricating oil target calculation model to obtain various performance parameter target values of the oil-cooled electric drive integrated system standard lubricating oil, wherein the lubricating oil target calculation model integrates various performance calculation sub-models of the lubricating oil;

[0116] The test unit 302 is used to select the lubricating oil to be selected to perform various performance test experiments to obtain various performance parameter test values;

[0117] The judgment unit 303 is used to compare the various performance parameter test values with the various performance parameter target values, and if the preset condition is met, the lubricating oil to be selected is selected as the oil-cooled electric drive integrated system lubricating oil.

Claims

1. A method for selecting a lubricating oil for an oil-cooled electric drive integrated system, characterized by, The application relates to an oil-cooled electric drive integrated system lubricating oil selection method. acquiring various operation parameters of an oil-cooled electric drive integrated system; inputting the various operation parameters into a pre-constructed lubricating oil target calculation model to obtain various performance parameter target values of standard lubricating oil of the oil-cooled electric drive integrated system, wherein the lubricating oil target calculation model is integrated with various performance calculation sub-models of lubricating oil; selecting lubricating oil to be selected to perform various performance test experiments to obtain various performance parameter test values; comparing the various performance parameter test values with the various performance parameter target values, and if a preset condition is met, selecting the lubricating oil to be selected as lubricating oil of the oil-cooled electric drive integrated system.

2. The method for selecting lubricating oil for an oil-cooled electric drive integrated system according to claim 1, characterized in that: The various operation parameters of the oil-cooled electric drive integrated system include gear surface contact stress, input rotating speed, oil cooler cooling water temperature, motor voltage and motor working temperature of the oil-cooled electric drive integrated system. The various performance parameters of the lubricating oil include anti-wear performance parameters, shear stability performance parameters, oxidation stability performance parameters, breakdown voltage performance parameters and thermal conductivity performance parameters.

3. The method for selecting lubricating oil for an oil-cooled electric drive integrated system according to claim 2, characterized in that: The various performance parameter target values of the standard lubricating oil of the oil-cooled electric drive integrated system obtained by inputting the various operation parameters into the pre-constructed lubricating oil target calculation model include: inputting an upper limit value of the gear surface contact stress into an anti-wear calculation sub-model of the lubricating oil to determine a FZG gear gluing test grade, and taking the FZG gear gluing test grade as an anti-wear parameter target value; inputting an upper limit value of the rotating speed into a shear stability calculation sub-model of the lubricating oil to determine an upper limit value of a viscosity drop of the lubricating oil at a set temperature after a KRL shear stability test, and taking the upper limit value as a shear stability parameter target value; inputting an upper limit value of the oil cooler cooling water temperature into an oxidation stability calculation sub-model to determine an upper limit value of an acid value change rate of the lubricating oil after a DKA oxidation stability test, and taking the upper limit value as an oxidation stability parameter target value; inputting an upper limit value of the motor voltage into a breakdown voltage calculation sub-model to determine a lower limit value of the breakdown voltage of the lubricating oil, and taking the lower limit value as a breakdown voltage parameter target value; inputting an upper limit value of the motor working temperature into a thermal conductivity calculation sub-model to determine a lower limit value of the thermal conductivity of the lubricating oil, and taking the lower limit value as a thermal conductivity parameter target value.

4. The method of claim 3, wherein the lubricating oil is selected from the group consisting of a mineral oil, a synthetic oil, and a mixture thereof. The construction of the anti-wear calculation sub-model of the lubricating oil includes: based on a FZG gear gluing test grade, an upper limit value of gear surface contact stress and an anti-wear influence coefficient, an anti-wear calculation sub-model of the lubricating oil is constructed, wherein the FZG gear gluing test grade is directly proportional to the upper limit value of the gear surface contact stress and the anti-wear influence coefficient.

5. The method for selecting lubricating oil for an oil-cooled electric drive integrated system according to claim 3, characterized in that: The construction of the shear stability calculation sub-model of the lubricating oil includes: based on a viscosity drop of the lubricating oil at a set temperature after a KRL shear stability test, an upper limit value of the rotating speed and a shear stability influence coefficient, a shear stability calculation sub-model of the lubricating oil is constructed, wherein the viscosity drop of the lubricating oil at the set temperature after the KRL shear stability test is directly proportional to the upper limit value of the rotating speed and the shear stability influence coefficient.

6. The method for selecting lubricating oil for an oil-cooled electric drive integrated system according to claim 3, characterized in that: The construction of the oxidation stability calculation sub-model includes: The acid value change of the lubricating oil after the DKA oxidation stability test, the upper limit value of the oil cooler cooling water temperature, and the oxidation stability influence coefficient are used to construct an oxidation stability calculation sub-model, wherein the acid value change of the lubricating oil after the DKA oxidation stability test is proportional to the upper limit value of the oil cooler cooling water temperature and the oxidation stability influence coefficient.

7. The method of claim 3, wherein the lubricating oil is selected from the group consisting of a mineral oil, a synthetic oil, and a mixture thereof. The construction of the breakdown voltage calculation sub-model includes: The breakdown voltage of the lubricating oil, the upper limit value of the motor voltage, and the breakdown voltage influence coefficient are used to construct a breakdown voltage calculation sub-model, wherein the breakdown voltage of the lubricating oil is proportional to the upper limit value of the motor voltage and the breakdown voltage influence coefficient.

8. The method for selecting lubricating oil for an oil-cooled electric drive integrated system according to claim 3, characterized in that: The construction of the thermal conductivity calculation sub-model includes: The thermal conductivity of the lubricating oil, the upper limit value of the motor operating temperature, and the thermal conductivity influence coefficient are used to construct a thermal conductivity calculation sub-model, wherein the thermal conductivity of the lubricating oil is proportional to the upper limit value of the motor operating temperature and the thermal conductivity influence coefficient.

9. The method for selecting lubricating oil for an oil-cooled electric drive integrated system according to claim 2, characterized in that: The performance parameter test values are compared with the performance parameter target values, and if a preset condition is met, the lubricating oil to be selected is selected as the oil-cooled electric drive integrated system lubricating oil, including: If at least three of the anti-wear performance parameter test value, the shear stability performance parameter test value, the oxidation stability performance parameter test value, the breakdown voltage performance parameter test value, and the thermal conductivity performance parameter test value of the lubricating oil to be selected meet the corresponding performance parameter target value, the lubricating oil to be selected is selected as the oil-cooled electric drive integrated system lubricating oil.

10. A lubricating oil selection system for an oil-cooled electric drive integrated system, characterized by, Including: An acquisition unit is configured to acquire various operating parameters of an oil-cooled electric drive integrated system; A calculation unit is configured to input the various operating parameters into a pre-constructed lubricating oil target calculation model to obtain various performance parameter target values of a standard lubricating oil for the oil-cooled electric drive integrated system, wherein the lubricating oil target calculation model integrates various performance calculation sub-models of the lubricating oil; A test unit is configured to select a lubricating oil to be selected to perform various performance test experiments to obtain various performance parameter test values; A judgment unit is configured to compare the various performance parameter test values with the various performance parameter target values, and if a preset condition is met, the lubricating oil to be selected is selected as the oil-cooled electric drive integrated system lubricating oil.

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