A grease performance testing method and system

Abstract

The present invention relates to the technical field of lubricating material testing, and in particular to a grease performance testing method and system, including: obtaining a test current data sequence and a control current data sequence of the grease to be tested at different test temperatures; determining the lubrication performance index at each test temperature according to the difference between the test current data sequence and the control current data sequence; analyzing the stability of the change of local test current data according to the test current data sequence, and determining the lubrication performance stability index at each test temperature; determining the final quality index of the grease to be tested according to the lubrication performance index and the lubrication performance stability index; and determining whether the quality of the grease to be tested is qualified by using the final quality index of the grease to be tested. The present invention analyzes the grease quality by combining the influence of the temperature in the test environment on the grease performance test, thereby effectively improving the accuracy of the grease performance test results.

Description

Technical Field

[0001] The invention relates to the technical field of lubricating material testing, and in particular to a grease performance testing method and system. Background Art

[0002] Grease is a semi-solid material used to reduce friction, wear and energy loss. It is usually composed of base oil, thickener and additives. It is mainly used for the lubrication of mechanical equipment, especially in cases where liquid lubricants cannot be used effectively, such as bearings, gears and hinges. In order to ensure that the grease can meet the actual application standards and achieve the functions of service life prediction, the performance test of the grease is required.

[0003] The SRV (Stress / Strain Rheometer for Lubricants) test system is generally used to test the lubrication performance of grease. Specifically, under a certain temperature and load, a vibrating or reciprocating slider is used to rub on the surface of the sample to measure the friction coefficient and wear of the grease. However, the SRV test system test process is time-consuming and requires testing under certain environmental conditions such as temperature and humidity to ensure the consistency and repeatability of the test conditions; if the test environment is unstable, such as a large change in temperature, it will lead to inconsistency in the test environment conditions, which will affect the performance of the grease under different test conditions, and thus affect the accuracy of the test results. Among them, temperature changes will change the fluidity and viscosity of the grease, thereby affecting the measurement results of the friction coefficient. Summary of the invention

[0004] In order to solve the technical problem of low accuracy of the test results of the above-mentioned existing grease performance test method, the purpose of the present invention is to provide a grease performance test method and system, and the technical solution adopted is as follows:

[0005] The present invention provides a method for testing the performance of a lubricating grease, the method comprising the following steps:

[0006] Acquire a test current data sequence and a control current data sequence of the tested grease at different test temperatures;

[0007] Determine the lubrication performance index of the tested grease at each test temperature according to the difference between the test current data sequence and the control current data sequence at the same test temperature;

[0008] Analyze the stability of local test current data changes according to the test current data sequence at each test temperature, and determine the lubrication performance stability index of the tested grease at each test temperature;

[0009] Determining the final quality index of the lubricating grease to be tested according to each test temperature, the lubricating performance index at each test temperature, and the lubricating performance stability index;

[0010] The final quality index of the lubricating grease to be tested is used to determine whether the quality of the lubricating grease to be tested is qualified.

[0011] Furthermore, the test current in the test current data sequence is the operating current data corresponding to the test components in the grease testing equipment that are coated with the grease to be tested; the control current data in the control current data sequence is the operating current data corresponding to the test components in the grease testing equipment that are not coated with the grease to be tested.

[0012] Further, the determining of the lubrication performance index of the tested grease at each test temperature according to the difference between the test current data sequence and the control current data sequence at the same test temperature includes:

[0013] Taking any test temperature as the target test temperature, determining the first lubrication performance factor of the tested grease at the target test temperature according to the ratio between the control current data and the test current data at the same time at the target test temperature;

[0014] Determining a second lubrication performance factor of the lubricating grease to be tested at the target test temperature according to the test current data sequence and the control current data sequence at the target test temperature;

[0015] The lubrication performance index of the lubricating grease to be tested at the target test temperature is determined by combining the first lubrication performance factor and the second lubrication performance factor of the lubricating grease to be tested at the target test temperature.

[0016] Further, determining the second lubrication performance factor of the tested grease at the target test temperature according to the test current data sequence and the control current data sequence at the target test temperature includes:

[0017] Determine that the maximum difference value corresponding to the control current data sequence is a first difference value, and determine that the maximum difference value corresponding to the test current data sequence is a second difference value;

[0018] Determine a second lubrication performance factor of the tested grease at a target test temperature by combining the first difference value and the second difference value;

[0019] The maximum difference value is equal to the difference between the maximum value and the minimum value in the sequence, the first difference value is positively correlated with the second lubrication performance factor, and the second difference value is negatively correlated with the second lubrication performance factor.

[0020] Further, analyzing the stability of local test current data changes according to the test current data sequence at each test temperature to determine the lubrication performance stability index of the tested grease at each test temperature includes:

[0021] Partitioning the test current data sequence at the target test temperature locally to obtain a test current data subsequence at each moment;

[0022] Determine the lubrication performance stability factor of the test current data subsequence at each moment according to the test current data subsequence at each moment under the target test temperature;

[0023] According to the lubrication performance stability factor of the test current data subsequence at each moment, the lubrication performance stability index of the tested grease at the target test temperature is determined.

[0024] Further, the determining of the lubrication performance stability factor of the test current data subsequence at each moment according to the test current data subsequence at each moment under the target test temperature includes:

[0025] Calculate the average value of the difference between each test current data in the test current data subsequence at each moment and the average value of the test current data in the test current data subsequence at the corresponding moment, and record it as the first lubrication performance fluctuation degree at each moment;

[0026] Analyzing the trend fluctuation of all test current data in the test current data subsequence according to the test current data subsequence at each moment, and determining the fluctuation degree of the second lubrication performance at each moment;

[0027] Determine the lubrication performance stability factor of the test current data subsequence at each moment by combining the first lubrication performance fluctuation degree and the second lubrication performance fluctuation degree at each moment;

[0028] Among them, the first lubrication performance fluctuation degree and the second lubrication performance fluctuation degree are both negatively correlated with the lubrication performance stability factor.

[0029] Furthermore, the lubrication performance stability index of the tested grease at the target test temperature is determined according to the lubrication performance stability factor of the test current data subsequence at each moment, including:

[0030] The maximum lubrication performance stability factor is taken as the target stability factor, and other lubrication performance stability factors except the target stability factor are taken as comparison stability factors;

[0031] The lubrication performance stability index of the tested grease at the target test temperature is determined by combining the target stability factor and the difference between the target stability factor and each of the comparison stability factors.

[0032] Further, the final quality index of the grease to be tested is determined according to each test temperature, the lubrication performance index at each test temperature, and the lubrication performance stability index, including:

[0033] Determine the initial quality index of the tested grease at each test temperature according to the lubrication performance index and the lubrication performance stability index at each test temperature;

[0034] Determine the largest initial quality index as the target quality index, and use other initial quality indexes except the target quality index as comparative quality indexes;

[0035] The final quality index of the lubricating grease to be tested is determined based on the target quality index and its corresponding test temperature, each comparison quality index and its corresponding test temperature, and the average value of all initial quality indexes.

[0036] Further, the final quality index of the grease to be tested is determined according to the target quality index and its corresponding test temperature, each comparison quality index and its corresponding test temperature, and the average value of all initial quality indexes, including:

[0037] Calculate the difference between the target quality index and each comparison quality index, and record it as the index difference; and calculate the difference between the test temperature corresponding to the target quality index and the test temperature corresponding to each comparison quality index, and record it as the temperature difference value;

[0038] Determine the ratio of the index difference value and the temperature difference value corresponding to the same comparative quality index, and use the average value of all ratios as the test temperature influence degree;

[0039] Determine the final quality index of the grease to be tested by combining the degree of influence of the test temperature and the average value of all the initial quality indexes;

[0040] The influence degree of the test temperature is negatively correlated with the final quality index, and the average value of all the initial quality indexes is positively correlated with the final quality index.

[0041] The present invention also provides a grease performance testing system, comprising:

[0042] A data acquisition module, used for acquiring a test current data sequence and a control current data sequence of the tested grease at different test temperatures;

[0043] A first determination module, used for determining the lubrication performance index of the tested grease at each test temperature according to the difference between the test current data sequence and the control current data sequence at the same test temperature;

[0044] A second determination module is used to analyze the stability of local test current data changes according to the test current data sequence at each test temperature, and determine the lubrication performance stability index of the tested grease at each test temperature;

[0045] A third determination module is used to determine the final quality index of the grease to be tested according to each test temperature, the lubrication performance index at each test temperature, and the lubrication performance stability index;

[0046] The quality testing module is used to determine whether the quality of the lubricating grease to be tested is qualified by using the final quality index of the lubricating grease to be tested.

[0047] The present invention has the following beneficial effects:

[0048] The present invention provides a grease performance testing method and system, which takes into account the influence of different test temperatures on the performance test results when testing the performance quality of the grease, and helps to improve the accuracy of the grease performance test results. When analyzing the final quality index of the grease to be tested, not only the lubrication performance index at each test temperature is taken into account, but also the lubrication performance stability index at each test temperature is taken into account. The numerical accuracy of the final quality index determined by combining the two aspects is higher, which is convenient for obtaining grease performance test results with higher accuracy in the subsequent process; and when determining the final quality index, the influence of the test temperature on the performance test is increased. Compared with the existing SRV test system, the comprehensive performance analysis combined with the influence of the test temperature can further improve the reliability and reference value of the grease quality determination results. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0050] Figure 1 This is a flow chart of a method for testing the performance of a lubricating grease according to an embodiment of the present invention;

[0051] Figure 2 Flow chart of the implementation of step S2 in the embodiment of the present invention;

[0052] Figure 3 Flow chart of the implementation of step S3 in the embodiment of the present invention;

[0053] Figure 4 Flow chart of the implementation of step S4 in the embodiment of the present invention;

[0054] Figure 5 This is a structural diagram of a grease performance testing system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0055] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the technical solutions proposed by the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0056] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0057] The application scenarios targeted by the present invention may be:

[0058] The lubrication performance and lubrication stability of grease may be affected by temperature and its own quality, and the existing SRV test system's grease performance test does not consider the impact of test temperature changes on the test results, resulting in a deviation in the accuracy of the final performance test results. Therefore, in order to obtain more accurate quality indicators, it is necessary to conduct a more accurate measurement and analysis of the grease performance in combination with relevant influencing factors.

[0059] One embodiment of the present invention provides a method for testing the performance of a lubricating grease. Figure 1 As shown, the following steps are included:

[0060] S1, obtaining a test current data sequence and a control current data sequence of the tested grease at different test temperatures.

[0061] First of all, it should be noted that the performance and performance stability of grease are the main indicators for measuring the quality of grease, and the performance and performance stability of grease at different temperatures may be different. In order to test and analyze the performance of grease more accurately, it is necessary to collect test-related data of the grease to be tested at different test temperatures each time. Among them, the length of time used for a test can be set by the implementer, but the time used for each test should be the same, so as to facilitate the subsequent comprehensive analysis of test-related data of different test temperature dimensions.

[0062] For the grease performance test equipment, the test components of the test equipment in this embodiment refer to rollers. When performing performance tests on grease, multiple groups of rollers need to be prepared, with two rollers in each group. All rollers are test components made of the same material and with the same specifications, which can avoid the impact of the large errors that may exist between the test components on the grease performance test; one of the rollers in each group of rollers is evenly coated with the grease to be tested, and the other roller is not coated with the grease to be tested, and a group of rollers is placed on the bracket of the test equipment. The bracket is mainly divided into two brackets for fixing the rollers; at the same time, two highly sensitive brushless motors are arranged below the rollers to drive them to rotate, and a speed sensor is arranged on the side of the bracket, which is used as a monitoring feedback system for the brushless motor to maintain a constant speed; the test equipment uses PID (Proportional Integral Derivative) to control the speed of its brushless motor to be stable; the cover on the top of the test equipment has a heat preservation and heating function to simulate the performance of the grease at different test temperatures. The range of the test temperature can be set by the implementer according to the actual situation and is not specifically limited.

[0063] Specifically, in each test, first, a group of test rollers is installed on the test equipment, one of the rollers in the group of test rollers is coated with the grease to be tested, and the other is not coated with the grease to be tested, and the grease not coated can serve as a reference; secondly, after the group of test rollers is fixed to the bracket, the cover of the test equipment is closed, and the test temperature and the roller speed are adjusted; then, the resistance of the roller coated with grease when rotating is smaller than the resistance of the roller not coated with grease when rotating, so when the motor of the test equipment drives the friction device to rotate in the roller, the resistance felt by the motor is different, and in order to maintain the rotation speed of the roller, the roller with greater resistance requires a larger current, so the current data required for the motor to maintain the rotation speed during each test is collected by the current monitoring device in the monitoring feedback system, that is, the test current data sequence and the control current data sequence of the grease to be tested at different test temperatures are collected. Among them, the test current in the test current data sequence is the operating current data corresponding to the test component coated with the grease to be tested in the grease test equipment, and the control current data in the control current data sequence is the operating current data corresponding to the test component not coated with the grease to be tested in the grease test equipment.

[0064] After obtaining the test related data of the tested grease at each test temperature, the collected test related data can be sent to a computer receiving end through a wireless transmission module built into the test equipment, so as to analyze the quality of the tested grease.

[0065] S2, determining the lubrication performance index of the tested grease at each test temperature according to the difference between the test current data sequence and the control current data sequence at the same test temperature.

[0066] First of all, it should be noted that the grease performance test in this embodiment mainly tests the lubrication performance and temperature resistance of the grease during use, and the lubrication performance is one of the most important test results. During the application of the grease, the test components coated with the grease may generate high temperatures due to friction during long-term operation, or be affected by different external test temperatures, resulting in different lubrication performance indicators of the tested grease at different test temperatures.

[0067] In this embodiment, when the control current data at the same time under a certain test temperature is greater than the test current data, it means that the current collected by the component without grease is much greater than the current collected by the component with grease, which further indicates that the lubrication performance of the grease at the test temperature may be relatively high; the reason is that, under the same roller speed, the smaller the friction force of the test component with grease is when the motor drives it to rotate, the lower the resistance the motor encounters when maintaining the speed, and the smaller the current required to maintain the same speed. Therefore, by analyzing the test current data sequence and the control current data sequence at each test temperature, the lubrication performance index of the grease to be tested at each test temperature can be quantified.

[0068] The above step S2 can be Figure 2 The steps shown achieve:

[0069] S201, taking any test temperature as the target test temperature, and determining the first lubrication performance factor of the grease to be tested at the target test temperature according to the ratio between the control current data and the test current data at the same time at the target test temperature.

[0070] Specifically, based on the test current data sequence and the control current data sequence at the target test temperature, the ratio of the control current data and the test current data corresponding to the same moment at the target test temperature is obtained; the average value of the ratios at all moments is calculated, and the average value of the ratios at all moments is used as the first lubrication performance factor of the grease to be tested at the target test temperature.

[0071] It is worth noting that the current data of the grease testing equipment under normal operating conditions does not reach zero, that is, there is no test current data with a value of zero in the test current data sequence, so there is no possibility that the denominator of the ratio is zero.

[0072] S202, determining a second lubrication performance factor of the lubricating grease to be tested at the target test temperature according to the test current data sequence and the control current data sequence at the target test temperature.

[0073] Specifically, the maximum difference value corresponding to the control current data sequence is determined as the first difference value, and the maximum difference value corresponding to the test current data sequence is determined as the second difference value; the first difference value and the second difference value are combined to determine the second lubrication performance factor of the tested grease at the target test temperature. The first difference value and the second difference value are calculated in the same way, the maximum difference value is equal to the difference between the maximum value and the minimum value in the sequence, the first difference value is positively correlated with the second lubrication performance factor, and the second difference value is negatively correlated with the second lubrication performance factor.

[0074] S203, determining a lubrication performance index of the lubricating grease to be tested at the target test temperature by combining the first lubrication performance factor and the second lubrication performance factor of the lubricating grease to be tested at the target test temperature.

[0075] Specifically, the product of the first lubrication performance factor and the second lubrication performance factor at the target test temperature is calculated, and the product of the two lubrication performance factors is used as the lubrication performance index of the grease to be tested at the target test temperature.

[0076] As an example, the calculation formula for the lubrication performance index of the tested grease at the xth test temperature can be:

[0077] ; In the formula, Indicates the lubrication performance index of the tested grease at the xth test temperature; represents the number of moments corresponding to the test current data sequence and the control current data sequence at the xth test temperature, t represents the moment sequence number, represents the reference current data at the tth moment in the reference current data sequence at the xth test temperature, represents the test current data at the tth moment in the test current data sequence at the xth test temperature, It represents the ratio of the control current data and the test current data at the tth moment under the xth test temperature. represents the first lubrication performance factor of the tested grease at the xth test temperature; represents the maximum difference value corresponding to the control current data sequence, that is, the first difference value, Indicates the maximum difference value corresponding to the test current data sequence, which is the second difference value. represents a hyperparameter, and its empirical value is 0.001. It represents the second lubrication performance factor of the tested grease at the xth test temperature.

[0078] In the calculation formula of lubrication performance index, It represents the ratio between the control current data and the test current data at the tth moment under the xth test temperature. The larger the value, the smaller the test current data at the tth moment is relative to the control current data at the tth moment. When the test current data is smaller, it indicates that the lubrication performance of the grease to be tested at the tth moment at the xth test temperature is higher. Therefore, the first lubrication performance factor Lubrication performance indicators There is a positive correlation, that is, the larger the first lubrication performance factor is, the larger the lubrication performance index is; It represents the ratio between the variation range of the current sequence obtained by the ungreased test component and the variation range of the current sequence obtained by the greased test component at the xth test temperature. Due to the extreme case that all the test current data in the test current data sequence are equal, a hyperparameter is added to the denominator of the fraction. The implementer can set the size of the hyperparameter according to the actual situation. The larger the value, the smaller the test resistance range of the test component with grease applied is compared with the test component without grease applied at the xth test temperature, and the better the lubrication performance of the grease to be tested. Therefore, the second lubrication performance factor Lubrication performance indicators It also shows a positive correlation. The larger the second lubrication performance factor is, the greater the lubrication performance index is.

[0079] Finally, referring to the determination process of the lubrication performance index of the lubricating grease to be tested at the target test temperature, the lubrication performance index of the lubricating grease to be tested at each test temperature can be obtained.

[0080] S3, analyzing the stability of the local test current data changes according to the test current data sequence at each test temperature, and determining the lubrication performance stability index of the tested grease at each test temperature.

[0081] First of all, it should be noted that during the use of grease, air oxidation, emulsification, additive consumption and oil separation may cause the grease to become thinner, dry, hard or dirty, affecting its lubrication effect. Therefore, the analysis of the performance stability of the grease is also very important for the grease performance test results. The performance stability of the grease may vary at different test temperatures. Therefore, it is necessary to combine the test current data sequence at each test temperature to determine the lubrication performance stability index of the grease to be tested at each test temperature.

[0082] In this embodiment, for the grease to be tested at each test temperature, when the grease to be tested is disturbed by temperature, oxidation, etc., the lubrication performance of the grease to be tested may be unstable. In this case, a certain local test current data change in the test current data sequence at the corresponding test temperature may be relatively stable, while the remaining test current data excluding the local part may be different from the stable part. Based on this principle, the lubrication performance stability index of the grease to be tested at each test temperature is quantified.

[0083] The above step S3 can be Figure 3 The steps shown achieve:

[0084] S301 , locally dividing a test current data sequence at a target test temperature to obtain a test current data subsequence at each moment.

[0085] Specifically, a sliding window of size 5 is established, that is, the preset size is 5 test current data, and the test current data sequence at the target test temperature is slid according to the step size 1, and the test current data in each sliding area is used as the test current data subsequence at the corresponding moment, and the test current data subsequence can be characterized as a local test current sequence part. Among them, the size of the sliding window and the sliding step size can be set by the implementer according to the specific actual situation, and no specific limitation is made.

[0086] Of course, the implementer may also adopt other data division methods to determine the test current data subsequence at each moment, and there is no specific limitation on the method for determining the test current data subsequence. For example, for the test current data at each moment in the test current data sequence at the target test temperature, determine the test current data at several moments that are located around the test current data at a certain moment and are relatively close, and use the subsequence composed of the test current data at that moment and the determined test current data at several moments as the test current data subsequence at that moment.

[0087] S302, determining the lubrication performance stability factor of the test current data subsequence at each moment according to the test current data subsequence at each moment under the target test temperature.

[0088] It should be noted that in order to obtain the overall grease performance stability at the target test temperature, it is necessary to first determine the partial stability of the local test current sequence at each moment, that is, the lubrication performance stability factor of the test current data subsequence at each moment.

[0089] The above step S302 can be implemented through steps S312 to S332 (not shown in the figure):

[0090] S312, calculating the average value of the difference between each test current data in the test current data subsequence at each moment and the average value of the test current data in the test current data subsequence at the corresponding moment, and recording it as the first lubrication performance fluctuation degree at each moment.

[0091] S322, analyzing the trend fluctuation of all test current data in the test current data subsequence according to the test current data subsequence at each moment, and determining the fluctuation degree of the second lubrication performance at each moment.

[0092] Specifically, for each test current data subsequence at a moment, a first-order difference process is performed on the test current data subsequence to obtain a difference sequence, and the average value of all data in the difference sequence is used as the second lubrication performance fluctuation degree, thereby determining the second lubrication performance fluctuation degree at each moment. Among them, the implementation means of the first-order difference is a prior art and is not within the protection scope of the present invention, and will not be elaborated here.

[0093] Of course, implementers may analyze the trend fluctuation of all test current data in the current data subsequence by other calculation methods, such as standard deviation or variance.

[0094] S332, combining the first lubrication performance fluctuation degree and the second lubrication performance fluctuation degree at each moment, determining the lubrication performance stability factor of the test current data subsequence at each moment.

[0095] Specifically, the product of the first lubrication performance fluctuation degree and the second lubrication performance fluctuation degree at the same moment is calculated, the product is normalized using a linear function to obtain the normalized result value, and the difference between 1 and the result value is used as the lubrication performance stability factor of the test current data subsequence at the corresponding moment.

[0096] As an example, the calculation formula of the lubrication performance stability factor of the test current data subsequence at the tth moment can be:

[0097] ; In the formula, represents the lubrication performance stability factor of the test current data subsequence at the t-th moment, norm represents the linear normalization function, h represents the number of test current data in the test current data subsequence, s represents the test current data sequence number of the test current data subsequence, represents the sth test current data in the test current data subsequence at the tth moment, represents the average value of the test current data of the test current data subsequence at the tth moment, represents the absolute value function, represents the first lubrication performance fluctuation degree at the tth moment, Indicates the second lubrication performance fluctuation degree at the tth moment.

[0098] In the calculation formula of the lubrication performance stability factor, the first lubrication performance fluctuation degree and the second lubrication performance fluctuation degree are both negatively correlated with the lubrication performance stability factor. The smaller it is, the smaller the local data fluctuation of the test current data subsequence at the t-th moment is, that is, the more stable the test current data change of the test current data subsequence at the t-th moment is, and the greater the lubrication performance stability factor of the test current data subsequence at the t-th moment is; The closer it is to 0, the smaller the change trend of the test current data subsequence at the tth moment is, and the larger the lubrication performance stability factor of the test current data subsequence at the tth moment is; the lubrication performance stability factor determined by the two fluctuation-related factors is more reliable, which provides data support for subsequent calculation steps, and is conducive to enhancing the numerical accuracy of the lubrication performance stability index calculated subsequently.

[0099] S303, determining a lubrication performance stability index of the lubricating grease to be tested at a target test temperature according to the lubrication performance stability factor of the test current data subsequence at each moment.

[0100] In this embodiment, by traversing the test current data subsequence at each moment under the target test temperature, the maximum lubrication performance stability factor is determined, and the maximum lubrication performance stability factor is used as the reference part, and the difference between the stability degree of the remaining test current data subsequence and the stability degree of the reference part is analyzed, and then the lubrication performance stability of the tested grease under the target test temperature is obtained by analyzing the difference. Because the performance stability of the grease may show a downward trend over time with the use time and the operating temperature of the component during the use of the test component, it is necessary to quantify the lubrication performance stability index of the tested grease under the target test temperature.

[0101] Specifically, the maximum lubrication performance stability factor is taken as the target stability factor, and the other lubrication performance stability factors except the target stability factor are taken as comparison stability factors; the lubrication performance stability index of the tested grease at the target test temperature is determined by combining the target stability factor and the difference between it and each comparison stability factor.

[0102] As an example, the calculation formula of the lubrication performance stability index of the tested grease at the Lth test temperature can be:

[0103] ; In the formula, It represents the stability index of lubrication performance of the tested grease at the Lth test temperature, and exp represents the exponential function with the natural constant e as the base. represents the target stability factor corresponding to the Lth test temperature, R represents the number of comparison stability factors, It represents the rth comparison stability factor of the target stability factor corresponding to the Lth test temperature.

[0104] In the calculation formula of the lubrication performance stability index, the larger the target stability factor is, the more stable the lubrication performance is at the Lth test temperature. The Lth test temperature can refer to the target test temperature. The stronger the lubrication performance stability of the tested grease at the Lth test temperature is, the larger the lubrication performance stability index is. It represents the average difference between the target stability factor and its corresponding comparison stability factors. The smaller it is, the smaller the difference between the comparative stability factors of the target stability factor is, and the closer the comparative stability factor is to the target stability factor. Since the target stability factor is obtained because the lubrication performance is the most stable, the closer the comparative stability factor is to the target stability factor, the greater the lubrication performance stability index will be.

[0105] By referring to the calculation process of the lubrication performance stability index of the lubricating grease to be tested at the Lth test temperature, the lubrication performance stability index of the lubricating grease to be tested at each test temperature can be obtained.

[0106] S4, determining the final quality index of the grease to be tested according to each test temperature, the lubrication performance index at each test temperature and the lubrication performance stability index.

[0107] First of all, it should be noted that after obtaining the lubrication performance index and lubrication performance stability index at each test temperature, combined with the test temperature, the final quality index of the grease to be tested can be obtained, and the final quality index can be used to measure the lubrication quality of the grease to be tested at different test temperatures.

[0108] The above step S4 can be performed by Figure 4 The steps shown achieve:

[0109] S401, determining the initial quality index of the lubricating grease to be tested at each test temperature according to the lubricating performance index and the lubricating performance stability index at each test temperature.

[0110] Specifically, without considering the unit, the product of the lubrication performance index and the lubrication performance stability index at the same test temperature is calculated, and the product is used as the initial quality index of the tested grease at the corresponding test temperature.

[0111] Of course, implementers can also achieve this through other calculation methods, for example, calculating the value of the lubrication performance index and the lubrication performance stability index added together at the same test temperature as the initial quality index.

[0112] It should be noted that compared with the grease test results obtained only based on lubrication performance indicators, the initial quality indicators determined by combining lubrication performance indicators and lubrication performance stability indicators are more reliable and take more comprehensive factors into consideration, which is conducive to improving the accuracy of the final grease performance test results.

[0113] S402, determining the largest initial quality indicator as the target quality indicator, and taking other initial quality indicators except the target quality indicator as comparison quality indicators.

[0114] S403, determining the final quality index of the lubricating grease to be tested according to the target quality index and its corresponding test temperature, each comparison quality index and its corresponding test temperature, and the average value of all initial quality indexes.

[0115] It should be noted that the temperature in the test environment of the grease to be tested may vary to a certain extent. If the lubricating performance of the grease to be tested is good at different temperatures, it can be said that the performance of the grease to be tested is less affected by the test temperature change in the actual application environment. The target quality index is used as the benchmark data, and the final quality index of the grease to be tested is determined by analyzing the changes in the grease performance index of the benchmark data at different test temperatures.

[0116] The above step S403 can be implemented through steps S413 to S433 (not shown in the figure):

[0117] S413, calculating the difference between the target quality index and each comparison quality index, recorded as the index difference; and calculating the difference between the test temperature corresponding to the target quality index and the test temperature corresponding to each comparison quality index, recorded as the temperature difference value.

[0118] S423, determining the ratio of the index difference value corresponding to the same comparison quality index to the temperature difference value, and taking the average value of all ratios as the test temperature influence degree.

[0119] S433, determining the final quality index of the grease to be tested by combining the degree of influence of the test temperature and the average value of all initial quality indexes.

[0120] As an example, the calculation formula for the final quality index of the tested grease can be:

[0121] ; In the formula, G represents the final quality index of the grease to be tested, norm represents the linear normalization function, z represents the number of the comparison quality index, u represents the sequence number of the comparison quality index, represents the target quality indicator, represents the u-th comparison quality index, Indicates the test temperature corresponding to the target quality index, represents the test temperature corresponding to the u-th comparison quality index, represents the average value of all initial quality indicators, represents the absolute value function, a represents the hyperparameter, Indicates the degree of influence of test temperature.

[0122] In the calculation formula of the final quality index, It represents the ratio of the difference between the target quality index and the u-th comparison quality index to the difference between the corresponding test temperatures. The smaller the ratio of the two differences, the less the performance of the grease to be tested is affected by the test temperature, and the higher the final quality index. Therefore, the degree of influence of the test temperature is negatively correlated with the final quality index. It is worth noting that the numerical value of each test temperature is different, so There is no zero situation; It represents the average value of the initial quality index of the tested grease at all test temperatures. The larger the value is, the better the performance quality of the grease to be tested may be. Therefore, the average value of all initial quality indicators is positively correlated with the final quality indicator. Used to prevent the denominator of the fraction from being 0, the empirical value is 0.001. Implementers can set the size of the hyperparameter based on actual conditions without making specific restrictions.

[0123] So far, this embodiment has obtained the final quality index of the grease to be tested.

[0124] S5, using the final quality index of the lubricating grease to be tested, determining whether the quality of the lubricating grease to be tested is qualified.

[0125] Specifically, after obtaining the final quality index of the grease to be tested, the judgment threshold can be set to 0.65 according to actual production needs. The implementer can set the size of the judgment threshold according to the specific actual situation without making specific restrictions; when the final quality index is greater than the judgment threshold, the quality of the grease to be tested is judged to be qualified; when the final quality index is not greater than the judgment threshold, the quality of the grease to be tested is judged to be unqualified.

[0126] It should be noted that, with reference to the above-mentioned process of determining the final quality index of the grease to be tested, different production batches of grease can be tested to determine the final quality index, and grease classification can be achieved based on the final quality index, which effectively improves the accuracy of grease quality judgment or classification.

[0127] Another embodiment of the present invention provides a grease performance testing system, such as Figure 5 As shown, including:

[0128] The data acquisition module 501 is used to acquire the test current data sequence and the control current data sequence of the tested grease at different test temperatures;

[0129] A first determination module 502, for determining the lubrication performance index of the tested grease at each test temperature according to the difference between the test current data sequence and the control current data sequence at the same test temperature;

[0130] The second determination module 503 is used to analyze the stability of the local test current data changes according to the test current data sequence at each test temperature, and determine the lubrication performance stability index of the tested grease at each test temperature;

[0131] A third determination module 504 is used to determine the final quality index of the grease to be tested according to each test temperature, the lubrication performance index at each test temperature, and the lubrication performance stability index;

[0132] The quality testing module 505 is used to determine whether the quality of the lubricating grease to be tested is qualified by using the final quality index of the lubricating grease to be tested.

[0133] In summary, the present invention provides a grease performance testing method and system, which takes into account the influence of different test temperatures on the performance test results when testing the performance quality of the grease, and helps to improve the accuracy of the grease performance test results. When analyzing the final quality index of the grease to be tested, not only the lubrication performance index at each test temperature is taken into account, but also the lubrication performance stability index at each test temperature is taken into account. The numerical accuracy of the final quality index determined by combining the two aspects is higher, which is convenient for obtaining more accurate grease performance test results in the future; and when determining the final quality index, the influence of the test temperature on the performance test is increased. Compared with the existing SRV test system, the comprehensive performance analysis combined with the influence of the test temperature can further improve the reliability and reference value of the grease quality judgment results.

[0134] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A method for testing grease performance, characterized in that: The following steps are involved: Acquire a test current data sequence and a control current data sequence of the tested grease at different test temperatures; Determine the lubrication performance index of the tested grease at each test temperature according to the difference between the test current data sequence and the control current data sequence at the same test temperature; Analyze the stability of local test current data changes according to the test current data sequence at each test temperature, and determine the lubrication performance stability index of the tested grease at each test temperature; Determining the final quality index of the lubricating grease to be tested according to each test temperature, the lubricating performance index at each test temperature, and the lubricating performance stability index; Using the final quality index of the lubricating grease to be tested, determining whether the quality of the lubricating grease to be tested is qualified; Determining the lubrication performance index of the tested grease at each test temperature according to the difference between the test current data sequence and the control current data sequence at the same test temperature includes: Taking any test temperature as the target test temperature, determining the first lubrication performance factor of the tested grease at the target test temperature according to the ratio between the control current data and the test current data at the same time at the target test temperature; Determining a second lubrication performance factor of the lubricating grease to be tested at the target test temperature according to the test current data sequence and the control current data sequence at the target test temperature; Determine the lubrication performance index of the lubricating grease to be tested at the target test temperature by combining the first lubrication performance factor and the second lubrication performance factor of the lubricating grease to be tested at the target test temperature; Determining the second lubrication performance factor of the tested grease at the target test temperature according to the test current data sequence and the control current data sequence at the target test temperature includes: Determine that the maximum difference value corresponding to the control current data sequence is a first difference value, and determine that the maximum difference value corresponding to the test current data sequence is a second difference value; Determine a second lubrication performance factor of the tested grease at a target test temperature by combining the first difference value and the second difference value; Wherein, the maximum difference value is equal to the difference between the maximum value and the minimum value in the sequence, the first difference value is positively correlated with the second lubrication performance factor, and the second difference value is negatively correlated with the second lubrication performance factor; The analyzing the stability of the local test current data changes according to the test current data sequence at each test temperature to determine the lubrication performance stability index of the tested grease at each test temperature includes: Partitioning the test current data sequence at the target test temperature locally to obtain a test current data subsequence at each moment; Determine the lubrication performance stability factor of the test current data subsequence at each moment according to the test current data subsequence at each moment under the target test temperature; Determine the lubrication performance stability index of the tested grease at the target test temperature according to the lubrication performance stability factor of the test current data subsequence at each moment; The step of determining the lubrication performance stability factor of the test current data subsequence at each moment according to the test current data subsequence at each moment under the target test temperature includes: Calculate the average value of the difference between each test current data in the test current data subsequence at each moment and the average value of the test current data in the test current data subsequence at the corresponding moment, and record it as the first lubrication performance fluctuation degree at each moment; Analyzing the trend fluctuation of all test current data in the test current data subsequence according to the test current data subsequence at each moment, and determining the fluctuation degree of the second lubrication performance at each moment; Determine the lubrication performance stability factor of the test current data subsequence at each moment by combining the first lubrication performance fluctuation degree and the second lubrication performance fluctuation degree at each moment; Wherein, the first lubrication performance fluctuation degree and the second lubrication performance fluctuation degree are both negatively correlated with the lubrication performance stability factor; The step of determining the lubrication performance stability index of the grease to be tested at the target test temperature according to the lubrication performance stability factor of the test current data subsequence at each moment includes: The maximum lubrication performance stability factor is taken as the target stability factor, and other lubrication performance stability factors except the target stability factor are taken as comparison stability factors; The lubrication performance stability index of the tested grease at the target test temperature is determined by combining the target stability factor and the difference between the target stability factor and each of the comparison stability factors.

2. A grease performance testing method according to claim 1, characterized in that: The test current in the test current data sequence is the operating current data corresponding to the test components in the grease testing device that are coated with the grease to be tested; The control current data in the control current data sequence are operating current data corresponding to the test components in the grease testing device that are not coated with the grease to be tested.

3. A grease performance testing method according to claim 1, characterized in that: Determining the final quality index of the grease to be tested according to each test temperature, the lubrication performance index at each test temperature, and the lubrication performance stability index includes: Determine the initial quality index of the tested grease at each test temperature according to the lubrication performance index and the lubrication performance stability index at each test temperature; Determine the largest initial quality index as the target quality index, and use other initial quality indexes except the target quality index as comparative quality indexes; The final quality index of the lubricating grease to be tested is determined based on the target quality index and its corresponding test temperature, each comparison quality index and its corresponding test temperature, and the average value of all initial quality indexes.

4. A grease performance testing method according to claim 3, characterized in that: The method of determining the final quality index of the grease to be tested according to the target quality index and its corresponding test temperature, each comparison quality index and its corresponding test temperature, and the average value of all initial quality indexes includes: Calculate the difference between the target quality index and each comparison quality index, and record it as the index difference; and calculate the difference between the test temperature corresponding to the target quality index and the test temperature corresponding to each comparison quality index, and record it as the temperature difference value; Determine the ratio of the index difference value and the temperature difference value corresponding to the same comparative quality index, and use the average value of all ratios as the test temperature influence degree; Determine the final quality index of the grease to be tested by combining the degree of influence of the test temperature and the average value of all the initial quality indexes; The influence degree of the test temperature is negatively correlated with the final quality index, and the average value of all the initial quality indexes is positively correlated with the final quality index.

5. A grease performance testing system, the system being used to implement the steps of a grease performance testing method as claimed in any one of claims 1 to 4, characterized in that: include: A data acquisition module, used for acquiring a test current data sequence and a control current data sequence of the tested grease at different test temperatures; A first determination module, used for determining the lubrication performance index of the tested grease at each test temperature according to the difference between the test current data sequence and the control current data sequence at the same test temperature; A second determination module is used to analyze the stability of local test current data changes according to the test current data sequence at each test temperature, and determine the lubrication performance stability index of the tested grease at each test temperature; A third determination module is used to determine the final quality index of the grease to be tested according to each test temperature, the lubrication performance index at each test temperature, and the lubrication performance stability index; The quality testing module is used to determine whether the quality of the lubricating grease to be tested is qualified by using the final quality index of the lubricating grease to be tested.

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