A quantitative design method for resisting unsteady damage of bearings

Abstract

The present invention relates to the technical field of quantitative design for unsteady damage of bearings, and specifically relates to a quantitative design method for resisting unsteady damage of bearings. According to the wear rate of bearings under different unsteady service conditions and the wear rate under steady state, an unsteady damage influence factor is obtained, and a basic database of unsteady service conditions - bearing materials - bearing unsteady damage influence factors is established. The bearings are modified by using bearing surface modification technology and solid-liquid composite lubrication control technology to obtain the unsteady damage influence factors of bearings with different modification means, and the unsteady damage improvement rate of the modified bearing materials is obtained. The correlation relationship among bearing materials - bearing modification process - unsteady damage improvement rate is obtained, and a modification database is established, so as to quickly select the most suitable bearing modification means under a certain unsteady service condition. Through this method, suitable bearing materials and surface modification means are found to quantitatively improve the unsteady damage resistance of bearings and extend the bearing life.

Description

Technical Field

[0001] The present invention relates to the technical field of quantitative design of unsteady damage of bearings, and particularly relates to a quantitative design method for resisting unsteady damage of bearings. Background Art

[0002] During the service process of bearings, with the change of working conditions, unsteady service conditions such as rapid acceleration / deceleration, rapid load change, high temperature / low temperature, and lack of oil with larger frequency amplitudes often occur, resulting in premature failure of bearings and even sudden accidents. In unsteady service environments such as rapid speed change and rapid load change, due to the large change rate of speed and load, the deformation of bearing materials and the dynamic response of the lubrication system are completely mismatched with the change rate of speed and load, leading to new damage and failure mechanisms of bearings.

[0003] Therefore, how to design a method that is reasonable, feasible, and ingenious, and through quantitative design, find suitable bearing materials and surface modification means to quantitatively improve the resistance of bearings to unsteady damage, significantly improve the performance of bearings, and extend the service life of bearings is a problem that needs to be solved at present. Summary of the Invention

[0004] In order to solve the technical problems such as the damage and failure mechanisms that occur during the unsteady service process of existing bearings, resulting in a significant reduction in the service life of bearings, the present invention provides a quantitative design method for resisting unsteady damage of bearings, which selects different bearing materials and surface modification means to quantitatively improve the resistance of bearings to unsteady damage, significantly improve the performance of bearings, and extend the service life of bearings.

[0005] The technical solution adopted by the present invention to solve the above technical problems is: a quantitative design method for resisting unsteady damage of bearings, comprising the following steps:

[0006] Step 1, select bearings of different materials, and set a variety of different service conditions for each material of bearings. Each service condition has unsteady conditions with changing working condition parameters and steady conditions after the working condition parameters are stabilized. Respectively obtain the unsteady damage amount w of bearings of different materials under different unsteady conditions 非稳态 and the steady damage amount w under steady conditions 稳态 , and calculate to obtain the influence factor of bearing unsteady damage ;

[0007] Step 2, associate the corresponding bearing materials, unsteady conditions, and the influence factor of bearing unsteady damage to establish a basic database of unsteady service conditions - bearing materials - influence factor of bearing unsteady damage;

[0008] Step 3: Modify the bearings using different anti-wear modification technologies for bearings respectively, and obtain the bearing unsteady damage influence factors of bearings modified by different technologies under different service conditions by using the method described in Step 1 ;

[0009] Step 4: Calculate the improvement rate of unsteady damage of the modified bearings based on the results of Step 3 and the basic database of Step 2 , obtain the correlation relationship among bearing materials, unsteady conditions, bearing modification processes, and the improvement rate of unsteady damage, and establish a corresponding modification database;

[0010] Step 5: Select the most suitable bearing modification means under the corresponding unsteady conditions from the modification database according to the required bearing materials and service conditions.

[0011] The above is the basic implementation mode of the present invention, and further improvements, perfection and limitations can be made on this basis: for example, the unsteady service conditions in Step 1 include four conditions of loading, accelerating, unloading, and decelerating.

[0012] The above is the basic implementation mode of the present invention, and further improvements, perfection and limitations can be made on this basis: for example, the unsteady damage amount w of the bearing under the unsteady conditions described in Step 1 非稳态 and the steady damage amount w under steady conditions 稳态 , according to the equal Hertz contact stress design principle, obtain the test load F under the reciprocating sliding test conditions from the load in the rolling unsteady test, the sliding speed v in the reciprocating sliding test is the linear velocity difference between the driving wheel and the steel ball in the rolling unsteady test, the wear scar area A in the reciprocating sliding test is measured by a three-dimensional profilometer, the sliding test time in the reciprocating sliding test is t, t is a fixed value, the reciprocating sliding stroke is L, L is a fixed value; according to the volume wear rate calculation formula , the unsteady damage amount w of the material under different rolling unsteady conditions 非稳态 and the steady damage amount w under steady conditions 稳态 can be obtained, so as to obtain the bearing unsteady damage influence factors under different unsteady conditions .

[0013] The above is the basic implementation mode of the present invention, and further improvements, perfection and limitations can be made on this basis: for example, the bearing materials used in Step 2 include GCr15 and 40Cr15Mo2VN bearing materials.

[0014] The above is the basic implementation mode of the present invention, and further improvements, perfection and limitations can be made on this basis: for example, in the third step, the modification treatment of the bearing includes solid-liquid composite lubrication control technology and bearing surface modification technology, wherein the bearing surface modification technology includes surface induction hardening process and carbonitriding process treatment of the bearing material.

[0015] The above is the basic implementation mode of the present invention, and further improvements, perfection and limitations can be made on this basis: for example, in the third step, the solid-liquid composite lubrication control technology includes adding different proportions of graphite to the lubricating oil of the bearing material.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] The present invention adopts a quantitative design method. By selecting different bearing materials and surface modification means, under different unsteady service conditions, through bearing surface modification technology and solid-liquid composite lubrication control technology, the bearing is modified to obtain the unsteady damage influence factors of bearings with different modification means, calculate the unsteady damage improvement rate of the modified bearing material, obtain the correlation relationship between bearing material - bearing modification process - unsteady damage improvement rate, and establish a corresponding modification database; finally, according to the user's needs, quickly select the most suitable bearing modification means under a certain unsteady service condition from the modification database.

[0018] The present invention can be used to quantitatively improve the unsteady damage resistance of bearings, can significantly improve the bearing performance and extend the bearing life. Specific implementation mode

[0019] The following further details the specific implementation mode of the present invention in combination with the table.

[0020] A quantitative design method for resisting unsteady damage of bearings includes the following steps:

[0021] Step 1: Select bearings of different materials, and set multiple different service conditions for each material bearing. Each service condition has an unsteady condition with changing working condition parameters and a steady state condition after the working condition parameters are stable. Through experiments, the unsteady damage amount w of bearings of different materials under different unsteady conditions is obtained 非稳态 and the steady damage amount w under the steady state condition 稳态 , and the unsteady damage influence factor of the bearing is calculated ;

[0022] Step 2: Associate the corresponding bearing material, unsteady condition and bearing unsteady damage influence factor to establish a basic database of unsteady service condition - bearing material - bearing unsteady damage influence factor;

[0023] Step 3: Modify the bearings using different anti-wear modification techniques for bearings respectively, and obtain the bearing non-steady-state damage influence factors of the bearings modified by different techniques under different service conditions by using the method described in Step 1. ;

[0024] Step 4: Calculate the non-steady-state damage improvement rate of the modified bearings based on the results of Step 3 and the basic database in Step 2. , obtain the correlation relationship among bearing materials, non-steady-state conditions, bearing modification processes, and non-steady-state damage improvement rates, and establish a corresponding modification database;

[0025] Step 5: Select the most suitable bearing modification means under the corresponding non-steady-state conditions from the modification database according to the required bearing materials and service conditions.

[0026] The above is the basic implementation mode of the present invention, and further improvements, perfection, and limitations can be made on this basis: for example, the non-steady-state service conditions in Step 1 include four conditions: loading, accelerating, unloading, and decelerating.

[0027] The above is the basic implementation mode of the present invention, and further improvements, perfection, and limitations can be made on this basis: for example, the non-steady-state damage amount w of the bearing under the non-steady-state conditions described in Step 1 非稳态 and the steady-state damage amount w under steady-state conditions 稳态 , according to the equal Hertz contact stress design principle, obtain the test load F under the reciprocating sliding test conditions from the load in the rolling non-steady-state test. The sliding speed v in the reciprocating sliding test is the linear velocity difference between the driving wheel and the steel ball in the rolling non-steady-state test. The wear scar area A in the reciprocating sliding test is measured by a three-dimensional profiler. The sliding test time in the reciprocating sliding test is t, where t is a constant value, and the reciprocating sliding stroke is L, where L is a constant value; according to the volume wear rate calculation formula , the non-steady-state damage amount w of the material under different rolling non-steady-state conditions 非稳态 and the steady-state damage amount w under steady-state conditions 稳态 can be obtained, so as to obtain the bearing non-steady-state damage influence factors under different non-steady-state conditions .

[0028] The above is the basic implementation mode of the present invention, and further improvements, perfection, and limitations can be made on this basis: for example, the bearing materials used in Step 2 include GCr15 and 40Cr15Mo2VN bearing materials.

[0029] The above is the basic implementation mode of the present invention, and further improvements, perfection and limitations can be made on this basis: for example, in the third step, the modification treatment of the bearing includes solid-liquid composite lubrication control technology and bearing surface modification technology, and the bearing surface modification technology includes surface induction hardening process and carbonitriding process treatment of the bearing material.

[0030] The above is the basic implementation mode of the present invention, and further improvements, perfection and limitations can be made on this basis: for example, in the third step, the solid-liquid composite lubrication control technology includes adding different proportions of graphite to the lubricating oil of the bearing material.

[0031] During actual tests, the non-steady-state damage influence factor is calculated in this embodiment The steps are as follows. According to the equal Hertz contact stress design principle, the test load F under the reciprocating sliding test conditions is obtained from the load in the rolling non-steady-state test. The sliding speed v in the reciprocating sliding test is the linear speed difference between the driving wheel and the steel ball in the rolling non-steady-state test. The wear scar area A in the reciprocating sliding test is measured by a three-dimensional profiler. The sliding test time t in the reciprocating sliding test is a fixed value, and the reciprocating sliding stroke L is a fixed value; according to the volume wear rate calculation formula , the non-steady-state damage amount w of the material under different rolling non-steady-state conditions can be obtained 非稳态 and the steady-state damage amount w under steady-state conditions 稳态 , so as to obtain the bearing non-steady-state damage influence factor under different non-steady-state conditions .

[0032] The following is the specific implementation process of the quantitative design test of the present invention.

[0033] Table 1 shows the non-steady-state damage influence factors of GCr15 bearing steel under different non-steady-state service conditions.

[0034] The non-steady-state service conditions include four conditions: loading, acceleration, unloading, and deceleration. In the loading test, the loading rates of No. 1-4 are the same, all 1 KN / min, so the single-cycle non-steady-state times are 60 s, 120 s, 180 s, and 360 s respectively. The loading rates of No. 5-6 are different, and the loading rates of No. 5 and 6 are 0.5 KN / min and 1.5 KN / min respectively. In the acceleration test, the acceleration rates of No. 7-9 are different, which are 60 rpm / s, 100 rpm / s, and 200 rpm / s respectively. In the unloading test, the unloading rates of No. 10 and No. 11 are the same, all 1 KN / min, so the single-cycle non-steady-state times are 240 s and 60 s respectively. The unloading rate of No. 12 is different, which is 0.5 KN / min. In the deceleration test, the deceleration rates of No. 13-15 are different, which are 60 rpm / s, 100 rpm / s, and 200 rpm / s respectively.

[0035] Table 1 Unsteady damage influence factors of GCr15 bearing steel under different unsteady service conditions.

[0036]

[0037] As can be seen from Table 1 above, the unsteady damage influence factors of the same bearing material under different service conditions are all different. And with the increase of the loading / unloading rate and the acceleration / deceleration rate,

[0038] the value gradually increases, the damage of the bearing material under unsteady service conditions intensifies, and the bearing life decreases.

[0039]

[0040] As can be seen from Table 2 above, the unsteady damage influence factors of the two bearing materials, GCr15 and 40Cr15Mo2VN, are also different. Compared with GCr15 steel, the unsteady damage influence factor

[0041] Table 2 Unsteady damage influence factors of different bearing materials under the same unsteady test conditions.

[0042] Under the same unsteady test conditions, different solid-liquid composite lubrication methods are used to improve the unsteady damage of GCr15 bearing steel, and its unsteady damage improvement rate is shown in Table 3. For No. 1, the solid-liquid composite lubrication method of adding 0.5 g / mL graphite to the lubricating oil is adopted. For No. 2, the solid-liquid composite lubrication method of adding 1.0 g / mL graphite to the lubricating oil is adopted. For No. 3, it is a control sample without adding graphite.

[0043] Table 3 Unsteady damage improvement rate of bearing materials under solid-liquid composite lubrication

[0044]

[0045] As can be seen from Table 3, under the same unsteady test conditions, after adding graphite to the lubricating oil, the unsteady damage influence factors of GCr15 steel all decrease, and the improvement rate of the No. 1 sample is 15.9%, which is greater than that of the No. 2 sample, indicating that the improvement effect of the unsteady damage of GCr15 steel is more significant after adding 0.5 g / mL of graphite.

[0046] Table 4 shows the improvement rate of unsteady damage of bearing materials after surface induction hardening modification.

[0047] Under the same unsteady test conditions, different surface induction hardening processes were used to improve the unsteady damage of 40Cr15Mo2VN bearing steel, and the improvement rate of its unsteady damage is shown in Table 4. The induction hardening process of No. 1 is: frequency 12.3 kHz, power 57 kW, water-based cooling condition, and quenching time is 7 s (Process 1). The induction hardening process of No. 2 is: frequency 12.3 kHz, power 57 kW, water-based cooling condition, and quenching time is 8 s (Process 2). The induction hardening process of No. 3 is: frequency 12.3 kHz, power 57 kW, water-based cooling condition, and quenching time is 9 s (Process 3). No. 4 is the control group sample, using the full quenching process, that is: heating and holding at 1030 °C for 60 min and then oil quenching, (-196 °C × 1 h cryogenic treatment + 400 °C × 1 h tempering) × 2.

[0048] Table 4 Improvement rate of unsteady damage of bearing materials after surface induction hardening modification

[0049]

[0050] It can be seen from Table 4 that under the same unsteady test conditions, compared with the fully quenched sample, the unsteady damage influence factor of 40Cr15Mo2VN bearing steel after surface induction hardening modification values are all reduced, indicating that the performance of the modified 40Cr15Mo2VN bearing steel has been improved. And the value of 40Cr15Mo2VN bearing steel after surface induction hardening (Process 2) is the smallest, and the value of surface induction hardening (Process 3) is the largest. It shows that surface induction hardening (Process 2) has a more excellent improvement rate of unsteady damage , the improvement rate of surface induction tempering (Process 1) is the second, and the improvement rate of surface induction hardening (Process 3) is lower.

[0051] Table 5 shows the improvement rate of unsteady damage of bearing materials after carbonitriding modification.

[0052] Under the same unsteady test conditions, different carbonitriding processes were used to improve the unsteady damage of GCr15 bearing steel, and the improvement rate of its unsteady damage is shown in Table 5.

[0053] The nitrocarburizing process of No. 1 is as follows: Nitrogen-methanol is used as the carrier gas, the nitrocarburizing temperature is 900 °C, the treatment time is 100 min, the quenching temperature is 860 °C, the holding time is 30 min, the carbon potential is controlled at 1.10% C, oil quenching, and tempering at 180 °C for 4 h (Process 1).

[0054] The nitrocarburizing process of No. 2 is as follows: Nitrogen-methanol is used as the carrier gas, the nitrocarburizing temperature is 825 °C, the treatment time is 580 min, the quenching temperature is 812 °C, the holding time is 35 min, the carbon potential is controlled at 1.18% C, oil quenching, and tempering at 180 °C for 4 h (Process 2).

[0055] The nitrocarburizing process of No. 3 is as follows: Nitrogen-methanol is used as the carrier gas, the nitrocarburizing temperature is 850 °C, the treatment time is 330 min, the quenching temperature is 850 °C, the holding time is 80 min, the carbon potential is controlled at 1.3% C, oil quenching, and tempering at 180 °C for 4 h (Process 3).

[0056] No. 4 is the control group sample, and the traditional quenching-tempering process is adopted, that is, the quenching temperature is 830 °C, oil quenching after holding for 35 min, and tempering at 150 °C for 4 h.

[0057] Table 5 Improvement rate of non-steady-state damage of bearing materials after nitrocarburizing modification

[0058]

[0059] As can be seen from Table 5, under the same non-steady-state test conditions, compared with the quenching-tempering samples, the non-steady-state damage influence factor value of GCr15 bearing steel after nitrocarburizing modification decreases, indicating that the performance of the modified GCr15 bearing steel has been improved. And the value of GCr15 bearing steel after nitrocarburizing (Process 2) is the smallest, and the value of nitrocarburizing (Process 1) is the largest. It shows that nitrocarburizing (Process 2) has a more excellent non-steady-state damage improvement rate , the improvement rate of nitrocarburizing (Process 3) is second, and the improvement rate of nitrocarburizing (Process 1) is lower.

[0060] As can be seen from Table 5, under the same non-steady-state test conditions, compared with the quenching-tempering samples, the non-steady-state damage influence factor value of GCr15 bearing steel after nitrocarburizing modification decreases, indicating that the performance of the modified GCr15 bearing steel has been improved. And the value of GCr15 bearing steel after nitrocarburizing (Process 2) is the smallest, and the The value is the largest. It shows that carbonitriding quenching (Process 2) has a more excellent improvement rate of unsteady-state damage , the improvement rate of carbonitriding quenching (Process 3) is the second, and the improvement rate of carbonitriding quenching (Process 1) is lower.

[0061] The preferred specific embodiments and examples of the present invention are described in detail above in combination with the table. However, the present invention is not limited to the above embodiments and examples, and various changes can be made without departing from the concept of the present invention within the scope of knowledge possessed by those skilled in the art.

Claims

1. A quantitative design method for resisting unsteady damage of bearings, characterized in that: It includes the following steps: Step 1: Select bearings made of different materials, and set multiple different service conditions for the bearings of each material. Each service condition has an unsteady condition with changing condition parameters and a steady state condition after the condition parameters stabilize. Through experiments, respectively obtain the unsteady damage amount w of bearings made of different materials under different unsteady conditions 非稳态 and the steady state damage amount w under the steady state condition 稳态 , and calculate the bearing unsteady damage influence factor η = w 非稳态 / w 稳态 ; Step 2: Associate the corresponding bearing materials, unsteady conditions, and bearing unsteady damage influence factors to establish a basic database of unsteady service conditions - bearing materials - bearing unsteady damage influence factors; Step 3: Modify the bearings respectively using different anti-wear modification technologies for bearings, and use the method described in Step 1 to obtain the bearing non-steady-state damage influence factor η of the bearings after modification by different technologies under different service conditions 改性 ; Step 4: According to the result of Step 3 and the basic database in Step 2, calculate the improvement rate η' of the unsteady-state damage of the modified bearing, where η'=(η - η 改性 ) / η, obtain the correlation relationship among the bearing material, unsteady-state conditions, bearing modification process, and unsteady-state damage improvement rate, and establish a corresponding modification database; Step 5: According to the required bearing materials and service conditions, select the most suitable bearing modification means under the corresponding unsteady conditions from the modified database; The unsteady damage amount w of the bearing under unsteady conditions described in Step 1 非稳态 and the steady damage amount w under steady conditions 稳态 , according to the equal Hertz contact stress design principle, the test load F under reciprocating sliding test conditions is obtained from the load in the rolling unsteady test. The sliding speed V in the reciprocating sliding test is the linear speed difference between the driving wheel and the steel ball in the rolling unsteady test. The wear scar area A in the reciprocating sliding test is measured by a three-dimensional profiler. The sliding test time in the reciprocating sliding test is t, where t is a fixed value, and the reciprocating sliding stroke is L, where L is a fixed value. According to the volume wear rate calculation formula w = AL / FVt, the unsteady damage amount w of the material under different rolling unsteady conditions can be obtained 非稳态 and the steady damage amount w under steady conditions 稳态 , thereby obtaining the bearing unsteady damage influence factor η = w 非稳态 / w 稳态 .

2. The quantitative design method for resisting unsteady damage of bearings according to claim 1, characterized in that: The unsteady service conditions in Step 1 include four conditions: loading, acceleration, unloading, and deceleration.

3. A quantitative design method for resisting unsteady damage of bearings according to claim 1, characterized in that: The bearing materials used in Step 2 include GCr15 and 40Cr15Mo2VN bearing materials.

4. A quantitative design method for resisting unsteady damage of bearings according to claim 1, characterized in that: The modification treatment of the bearing in Step 3 includes solid-liquid composite lubrication control technology and bearing surface modification technology. The bearing surface modification technology includes surface induction hardening process and carbonitriding process treatment of the bearing materials.

5. A quantitative design method for resisting unsteady damage of bearings according to claim 1, characterized in that: The solid-liquid composite lubrication control technology in Step 3 includes adding different proportions of graphite to the lubricating oil of the bearing materials.

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