Bearing remaining life diagnosis method and bearing remaining life diagnosis device

Abstract

The present invention suitably predicts a remaining life of a bearing. Provided is a bearing remaining life diagnosis method that predicts the remaining life of a rolling bearing which is for use in a rotary machine and which has inner and outer bearing rings and a rolling body between the bearing rings, said method comprising: a step for calculating the most recent estimated flaking length; and a step for calculating the most recent remaining life of the bearing on the basis of the most recent flaking length of a bearing ring. The step for calculating the most recent estimated flaking length includes a step for calculating the maximum rolling body load, a step for calculating the maximum contact surface pressure from the maximum rolling body load, and a step for calculating the most recent estimated flaking length of the bearing ring from the maximum contact surface pressure of the bearing ring.

Description

Bearing remaining life diagnosis method and bearing remaining life diagnosis device

[0001] The present invention relates to a bearing remaining life assessment method and a bearing remaining life assessment device.

[0002] Patent Document 1 describes a method for predicting and analyzing the progression of flaking in a rolling bearing by calculating the rolling element load while taking into account the shape of the flaking in the rolling bearing.

[0003] Patent No. 6844764

[0004] The calculation process for determining the remaining lifespan described in Patent Document 1 does not take into account the operating state of the mechanical equipment, which may result in an inappropriate prediction of the remaining lifespan.

[0005] In view of the above problems, an object of the present invention is to appropriately predict the remaining life of a bearing.

[0006] A bearing remaining life assessment method according to one aspect of the present invention is a bearing remaining life assessment method for predicting the remaining life of a rolling bearing used in a rotating machine, which has inner and outer raceways and rolling elements between the raceways, and includes the steps of calculating an estimated peeling length, which is an estimate of the length of peeling on the raceways, and calculating the remaining life of the bearing based on the estimated peeling length and a prediction of the operating status of the rotating machine, wherein the step of calculating the estimated peeling length includes the steps of calculating the maximum rolling element load from actual measurement data, calculating the maximum contact surface pressure from the maximum rolling element load, and calculating the estimated peeling length of the raceway from the maximum contact surface pressure of the raceway.

[0007] A bearing remaining life assessment device according to one embodiment of the present invention is a bearing remaining life assessment method for predicting the remaining life of a rolling bearing used in a rotating machine, which has inner and outer raceways and rolling elements between the raceways, and includes a peeling length acquisition unit that calculates an estimated peeling length, which is an estimate of the peeling length of the raceway, and a remaining life calculation unit that calculates the remaining life of the bearing based on a prediction of the estimated peeling length of the raceway and the operating status of the rotating machine, and the peeling length acquisition unit includes a maximum rolling element load calculation unit that calculates a maximum rolling element load from actual measurement data, a maximum contact surface pressure calculation unit that calculates a maximum contact surface pressure from the maximum rolling element load, and an estimated peeling length calculation unit that calculates an estimated peeling length of the raceway from the maximum contact surface pressure of the raceway.

[0008] According to the present invention, the remaining life of a rolling bearing can be appropriately predicted.

[0009] FIG. 1 is a schematic diagram showing an example of the overall configuration of a rotating machine and a bearing remaining life assessment system according to a first embodiment. FIG. 2 is a schematic structural diagram of a wind power generator. FIG. 3 is a schematic cross-sectional view of a bearing according to the first embodiment. FIG. 4 is a block diagram of a bearing remaining life assessment device according to the first embodiment. FIG. 5 is a flowchart of a bearing remaining life assessment method according to the first embodiment. FIG. 6 is a diagram showing an example of a graph showing the transition of the output of a generator. FIG. 7 is a diagram showing an example of a graph showing the transition of the rotation speed of a generator. FIG. 8 is a diagram showing an example of a graph showing the relationship between output and maximum rolling element load. FIG. 9 is a diagram showing an example of a graph showing the prediction of the progression of flaking length. FIG. 10 is a diagram showing the maximum rolling element load Q received from a rolling element immediately after the rolling element passes through flaking when a load P is applied to the bearing. ｍａｘ 11 is a schematic diagram showing the maximum rolling element load Q that the rolling element receives immediately after passing through the flaking in a state where a load P is applied to the bearing. ｍａｘFIG. 12 is a diagram illustrating the relationship between flaking length and operating time. FIG. 13 is a diagram illustrating a bearing remaining life assessment method according to a second embodiment. FIG. 14 is a diagram illustrating an example of a graph showing the relationship between a physical quantity measured by a sensor and a rolling element load. FIG. 15 is a plan view illustrating a bearing remaining life assessment method according to a third embodiment. FIG. 16 is a diagram illustrating an example of a graph showing the relationship between wind speed and maximum rolling element load. FIG. 17 is a diagram illustrating an example of a graph showing the relationship between a physical quantity related to vibration and a maximum rolling element load. FIG. 18 is a diagram illustrating an example of a method for estimating load ratio e. FIG. 19 is a diagram illustrating a different example of a method for estimating load ratio e. FIG. 20 is a diagram illustrating an example of a method for estimating load factor ε.

[0010] Hereinafter, modes for carrying out the invention (hereinafter, "embodiments") will be described in detail with reference to the drawings. Note that the present invention is not limited to the following embodiments. Furthermore, the components in the following embodiments include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and those that are within the so-called equivalent range. Furthermore, the components disclosed in the following embodiments can be combined as appropriate.

[0011] 1 is a schematic diagram showing an example of the overall configuration of a rotating machine and bearing remaining life assessment system according to a first embodiment. In the first embodiment, a wind power generator 100 is illustrated as an example of a rotating machine, but the present invention is not limited to this and can be applied to other rotating machines.

[0012] (Rotating Machine) A bearing remaining life assessment system 1 for a rotating machine according to an embodiment includes, for example, a detection device 10 provided in each wind power generator 100 in a collective wind power plant where multiple wind power generators 100 are installed on land or offshore, and a bearing remaining life assessment device 200 provided, for example, in a management facility within or outside the collective wind power plant.

[0013] 2 is a schematic structural diagram of a wind power generator. The wind power generator 100 includes a detection device 10, a rotor 30, a bearing 40, a speed-up gear 50, and a generator 60. The detection device 10, the bearing 40, the speed-up gear 50, and the generator 60 are housed in a nacelle 70. The speed-up gear 50 and the generator 60 are mounted on a base (frame) 90 supported by a tower 80.

[0014] The rotor 30 includes a hub 31 and a plurality of blades 32 provided on the hub 31. The hub 31 is connected to the gearbox 50 via a main shaft 51 and is rotatably supported by bearings 40. The main shaft 51 transmits to the gearbox 50 the rotational torque generated when the rotor 30 rotates as a result of the blades 32 receiving wind force.

[0015] 3 is a schematic cross-sectional view of a bearing according to the first embodiment. The rolling bearing 40 includes an inner ring 41 fitted onto the outside of a main shaft 51, an outer ring 42 fitted into a housing 44 or the like, a plurality of rolling elements 43 arranged to be able to roll between the inner ring 41 and the outer ring 42, and a cage (not shown) that holds the rolling elements 43 so that they can roll freely. In the first embodiment, flaking of the inner ring 41 occurs due to line contact between the rolling elements 43 and the raceway surfaces of the inner ring 41. Hereinafter, the direction along the circumference of the inner ring 41 may be simply referred to as the circumferential direction, the direction parallel to the rotation axis of the inner ring 41 as the axial direction, and the direction perpendicular to the axial direction and directed outward from the rotation axis of the inner ring 41 as the radial direction.

[0016] The speed-increasing gear 50 is provided between the main shaft 51 and the generator 60. The speed-increasing gear 50 is configured by, for example, a gear speed-increasing mechanism including a planetary gear, an intermediate shaft, a high-speed shaft, etc. provided in a gear box.

[0017] The speed-increasing gear 50 increases the rotational speed of the main shaft 51 and outputs the increased rotational torque to the generator 60 via a rotatably supported generator shaft 61. Although not specifically shown, a plurality of bearings that rotatably support a plurality of shafts are provided within the speed-increasing gear 50. Furthermore, lubricating oil is stored within the gear box of the speed-increasing gear 50 to oil-bath lubricate the gear speed-increasing mechanism.

[0018] The generator 60 generates electricity using the rotational torque received from the gearbox 50 via the generator shaft 61. The generator 60 is configured by, for example, an induction generator or a synchronous generator. Note that if the generator 60 is a synchronous generator capable of variable speed operation, the generator 60 may not have the gearbox 50.

[0019] The detection device 10 collects various data such as the state of the bearings 40 and the operating status of the wind power generator 100. In the first embodiment, the detection device 10 collects data correlating the output of the generator 60 with time. As shown in FIG. 1 , the detection device 10 outputs data collected by a data collection unit 11 to a bearing remaining life assessment device 200 via a network NW. The network NW may be, for example, an internet line or a local area network (LAN). Furthermore, a configuration may be adopted in which each wind power generator 100 in a collective wind power plant is connected via a LAN, and a virtual private network (VPN) is established between the wind power generators 100 and the LAN of an external management facility in which the bearing remaining life assessment device 200 is installed.

[0020] (Bearing remaining life assessment device) Figure 4 is a block diagram of a bearing remaining life assessment device according to the first embodiment. The bearing remaining life assessment device 200 can be said to be a computer that transmits and receives information to and from the detection device 10. For example, the bearing remaining life assessment device 200 is a computer that includes a calculation device that includes a calculation circuit such as a CPU (Central Processing Unit) and a storage unit 230, and performs processing by reading and executing a program (software) from the storage unit 230. As shown in Figure 4, the bearing remaining life assessment device 200 includes an input unit 210, a communication unit 240, the storage unit 230, an output unit 220, and a control unit 250.

[0021] The input unit 210 accepts input to the bearing remaining life assessment device 200. The input unit 210 is realized by an input device such as a keyboard, a mouse, or a touch panel, for example. The input unit 210 is not an essential component when processing is performed automatically.

[0022] The communication unit 240 is a communication module that communicates with an external device, and is, for example, an antenna, a cable, etc. The communication unit 240 may communicate with an external device such as the detection device 10 using any communication method.

[0023] The storage unit 230 is a memory that stores various information such as the calculation contents and programs of the control unit 250, and includes, for example, at least one of a main storage device such as a RAM (Random Access Memory) or a ROM (Read Only Memory), and an external storage device such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The program for the control unit 250 stored in the storage unit 230 may be stored in a recording medium that is readable by the bearing remaining life assessment device 200.

[0024] The output unit 220 outputs various information including the remaining life calculated by the bearing remaining life assessment device 200. The output unit 220 may be at least one of a display that outputs images and a speaker that outputs sounds.

[0025] The control unit 250 is a computing device and includes a computing circuit such as a CPU. The control unit 250 includes a peeling length acquisition unit 251 and a remaining life calculation unit 255. The peeling length acquisition unit 251 includes a maximum rolling element load calculation unit 252, a maximum contact surface pressure calculation unit 253, and an estimated peeling length calculation unit 254. The control unit 250 implements the peeling length acquisition unit 251 and the remaining life calculation unit 255 and performs their processing by reading and executing a program (software) from the storage unit 230. At least some of the processing of the peeling length acquisition unit 251 and the remaining life calculation unit 255 may be implemented by a hardware circuit. The control unit 250 may execute these processes using a single CPU, or may be equipped with multiple CPUs and execute the processes using the multiple CPUs. The processing performed by the peeling length acquisition unit 251, the maximum rolling element load calculation unit 252, the maximum contact surface pressure calculation unit 253, the estimated peeling length calculation unit 254, and the remaining life calculation unit 255 will be explained in the description of the bearing remaining life assessment method described below.

[0026] (Bearing Remaining Life Assessment Method) Figure 5 is a flowchart of a bearing remaining life assessment method according to the first embodiment. Below, the bearing remaining life assessment method according to the first embodiment will be described in detail according to the flow shown in Figure 5, using the bearing 40 used in the gear box 50 as an example. In the following description, flaking on the inner ring 41 will be simply referred to as flaking. Furthermore, the maximum circumferential length of flaking on the inner ring 41 will be simply referred to as flaking length.

[0027] The bearing remaining life assessment starts by starting monitoring of parameters related to bearing deterioration. The bearing remaining life assessment system 1 may be applied at the same time as a new bearing 40 is introduced into a rotating machine, or may be applied to a bearing 40 that is already in operation.

[0028] After the diagnosis begins, the detection device 10 acquires parameters related to bearing deterioration at predetermined intervals and transmits them to the bearing remaining life assessment device 200. The control unit 250 acquires the parameters related to bearing deterioration and determines whether the parameters are within a predetermined range (step S10). Here, the parameters related to bearing deterioration can be, for example, physical quantities related to the vibration of the bearing 40, the degree of lubricant deterioration, the amount of metal adhering to the lubricant filter, or other parameters that change when flaking occurs on the inner ring 41. The physical quantities related to vibration refer to the amplitude and frequency of at least one of the displacement, velocity, and acceleration associated with the vibration of the object being measured. Thus, the presence or absence of flaking can be detected by monitoring the parameters related to bearing deterioration. If the parameters related to bearing deterioration are within the predetermined range (step S10: Yes), the control unit 250 acquires the parameters related to bearing deterioration again after a predetermined period and again determines whether the parameters related to bearing deterioration are within the predetermined range (step S10).

[0029] (Acquisition of initial peeling length) If the parameter related to bearing deterioration is not within a predetermined range (step S10: No), the peeling length acquisition unit 251 determines whether initial peeling actual length data is stored in the memory unit 230 (step S21).

[0030] If the initial peeling actual length data is stored in the storage unit 230 (step S21: Yes), the peeling length acquisition unit 251 converts the initial peeling actual length data stored in the storage unit 230 into the initial peeling length A. ０ The measured length of initial flaking is an actual measurement value of the length of initial flaking obtained by directly measuring the inner ring 41 with a fiberscope or the like.

[0031] On the other hand, if the data of the measured length of the initial peeling is not stored in the storage unit 230 (step S21: No), the peeling length acquisition unit 251 determines an estimated length of the initial peeling (step S22) and sets the determined estimated length of the initial peeling as the initial peeling length A. ０ Here, the initial peeling length A ０ This refers to the flaking length that is acquired for the first time after the start of the bearing remaining life diagnosis. Note that if the bearing remaining life diagnosis system 1 is applied at the same time as the installation of a new rotating machine, the flaking length acquisition unit 251 may determine the initial estimated flaking length to be 0.

[0032] Initial peel length A ０ After obtaining the initial peeling length A ０ is threshold A ｌｉｍ It is determined whether the threshold value A is less than the threshold value A (step S31). ｌｉｍ More on this later.

[0033] Initial peel length A ０ is threshold A ｌｉｍ If the remaining life is less than the threshold value A (step S31: Yes), the remaining life calculation unit 255 predicts the future length of the peeling from the predicted operating conditions of the rotating machine, and calculates the remaining life from the predicted length of the peeling (step S32). The operating conditions of the rotating machine are predicted from the operating record of the same period of the previous year, etc. The remaining life is the time period from the time when the latest peeling length is acquired until the peeling length reaches the threshold value A. ｌｉｍ The remaining life calculation unit 255 outputs data including the calculated remaining life via the output unit 220 or the communication unit 240.

[0034] On the other hand, the initial peeling length A ０ is threshold A ｌｉｍIf this is the case (step S31: No), the control unit 250 does not calculate the remaining life, and outputs information that the bearing 40 has no remaining life via the output unit 220 or the communication unit 240. In this case, the bearing remaining life diagnosis device 200 ends the bearing remaining life diagnosis.

[0035] The peeling length acquisition unit 251 determines whether a predetermined period of time has elapsed since the previous calculation of the remaining life (Step S40). If the predetermined period of time has not elapsed since the previous calculation of the remaining life (Step S40: No), the latest peeling length is not acquired. On the other hand, if the predetermined period of time has elapsed since the previous calculation of the remaining life (Step S40: Yes), the peeling length acquisition unit 251 determines whether the latest measured peeling length data is stored in the memory unit 230 (Step S51).

[0036] If the latest measured peel length data is stored in the memory unit 230 (step S51: Yes), the peel length acquisition unit 251 stores the latest measured peel length data stored in the memory unit 230 as the peel length A. ｎ The peel length A is obtained as ｎ refers to the flaking length obtained the n+1th time after the start of the bearing remaining life diagnosis, where n is an integer of 1 or greater.

[0037] On the other hand, if the latest data on the measured length of initial flaking is not stored in the memory unit 230 (step S51: No), the flaking length acquisition unit 251 calculates the estimated flaking length using the maximum rolling element load calculation unit 252, the maximum contact surface pressure calculation unit 253, and the estimated flaking length calculation unit 254 (steps S52 to S54), and sets the calculated estimated flaking length as the latest flaking length A. ｎ Obtain as.

[0038] (Estimation of Separation Length) Hereinafter, a method for calculating the estimated separation length in the first embodiment will be described in detail using the bearing 40 used in the speed increaser 50 as an example. ｎis calculated from the output of the generator 60. More specifically, the operation data of the generator 60 is acquired, the operation status of the generator 60 is classified, the maximum rolling element load is calculated for each classification (step S52), the maximum contact surface pressure is calculated from the maximum rolling element load (step S53), and the estimated detachment length is calculated from the maximum contact surface pressure (step S54).

[0039] Fig. 6 is a diagram showing an example of a graph showing a transition in the output of the generator. Fig. 7 is a diagram showing an example of a graph showing a transition in the rotation speed of the generator. The detection device 10 collects data on the output and rotation speed of the generator 60 associated with time (operation data of the generator 60) shown in Figs. 6 and 7 and transmits it to the bearing remaining life assessment device 200. The peeling length acquisition unit 251 acquires the operation data of the generator 60 via the communication unit 240. Note that the data in Figs. 6 and 7 are schematic data for explaining the embodiment and are not actual data.

[0040] Table 1 is a table that compiles the data related to Figures 6 and 7. The separation length acquisition unit 251 generates data that compiles the operating time for each output operating condition from the operating data of the generator 60, as shown in Table 1. Specifically, as shown in Table 1, the separation length acquisition unit 251 sets categories for each output range and rotation speed range of the generator 60, and compiles the operating time for each category for the period since the previous remaining life calculation.

[0041]

[0042] 8 is a diagram showing an example of a graph showing the relationship between output and maximum rolling element load. The maximum rolling element load calculation unit 252 calculates the maximum rolling element load Q ｍａｘ In the first embodiment, the maximum rolling element load calculation unit 252 calculates the maximum rolling element load Q for each section from the output of the generator using the relationship shown in the graph of FIG. ｍａｘ Calculate the maximum rolling element load Q ｍａｘ The maximum load Q of the generator shown in FIG. 8 indicates the load at the position (maximum load position) where the load acting on the rolling element 43 (rolling element load) is the maximum among the loads acting on the rolling elements 43. ｍａｘThe relationship between the above is previously determined by measurement or analysis and stored in the storage unit 230.

[0043] The maximum contact surface pressure calculation unit 253 calculates the maximum rolling element load Q ｍａｘ From the above, the maximum contact pressure σ ｍａｘ (Step S53). ｍａｘ The maximum contact pressure σ refers to the contact pressure at the contact position where the contact pressure is maximum among the distribution of the contact pressure that the inner ring 41 receives from the rolling elements 43 at the maximum load position. ｍａｘ is calculated, for example, from equation (1) or equation (2) based on Hertz's theory. Equation (1) is the equation when the bearing 40 is a ball bearing. Equation (2) is the equation when the bearing 40 is a roller bearing. In equations (1) and (2), E is the modulus of longitudinal elasticity, m is Poisson's number, Σρ is the sum of the curvatures of the two objects, μ and ν are coefficients that determine the major and minor axes of the contact ellipse formed when the two objects are in elastic contact, and all of these take values ​​determined by the design of the bearing 40, etc. ｗｅ is the effective length of the rolling element 43, that is, the length obtained by subtracting the chamfered length of the rolling element 43 from the total length of the rolling element 43.

[0044]

[0045]

[0046] The separation estimation length calculation unit 254 calculates the maximum contact surface pressure σ for each section as shown in Table 1 and Equation (3). ｍａｘ and the number of stress cycles N, the amount of peeling progress a ｉ Calculate a ｉ The total amount of peeling progress Σa ｉ Calculate the previously obtained peel length A ｎ－１ The amount of peeling progress Σa ｉ By adding ｎ is calculated (step S54). The number of stress cycles N refers to the number of times that a point on the inner ring 41 repeatedly passes through the maximum load position. The number of stress cycles N is calculated for each section from the rotation speed and the operating time for each section. In addition, in equation (3), C and m are constants determined by the material, and F is a constant determined by the contact state between the rolling element 43 and the inner ring 41.

[0047]

[0048] The remaining life calculation unit 255 calculates the latest peeling length A ｎ is threshold A ｌｉｍ It is determined whether the threshold value A is less than the threshold value A (step S61). ｌｉｍ More on this later.

[0049] (Calculation of remaining life) Fig. 9 is a diagram showing an example of a graph showing a prediction of the progression of the flaking length. ｎ is threshold A ｌｉｍ If the remaining life is less than the latest separation length A (step S61: Yes), the remaining life calculation unit 255 predicts the future separation length from the predicted operating conditions of the rotating machine, and calculates the remaining life from the predicted separation length (step S62). The operating conditions of the rotating machine are predicted, for example, from the past operating records for the same month. The prediction of the future separation length is based on the most recent separation length A ｎ The data is updated every time a new value is acquired. １ In the example of FIG. 9, the separation length A is shorter than the first prediction at the beginning of February. ２ As a result of the acquisition, the prediction of the separation length was revised to the second prediction, and separation length A exceeded the second prediction in early March. ３ As a result of obtaining the latest separation length, the separation length prediction is revised to the third prediction. In this way, by updating the prediction of future separation growth according to the latest separation length and the latest operating conditions, it becomes possible to predict the separation length more accurately. Furthermore, the remaining life is also calculated based on the latest separation length A, just like the separation length. ｎ is acquired. This makes it possible to more accurately predict the remaining life from the most recent flaking length. The bearing remaining life assessment device 200 outputs data including the calculated remaining life from the output unit 220 or the communication unit 240.

[0050] On the other hand, the latest peeling length A ｎ is threshold A ｌｉｍIf not (step S61: No), the control unit 250 does not calculate the remaining life, and outputs information that the bearing 40 has no remaining life via the output unit 220 or the communication unit 240. In this case, the bearing remaining life diagnosis device 200 ends the bearing remaining life diagnosis.

[0051] In the first embodiment, the threshold value A of the peel length ｌｉｍ is equal to the distance between the rolling elements. Here, the distance between the rolling elements refers to the length along the circumferential direction between the contact points of two adjacent rolling elements 43 with the inner ring 41.

[0052] 10 and 11 show the maximum rolling element load Q received from the rolling element immediately after the rolling element passes through the flaking area when a load P is applied to the bearing. ｍａｘ As shown in FIG. 10, the peeling length A ｎ does not exceed the distance between the rolling elements, the maximum rolling element load Q ｍａｘ The rolling element 43b adjacent to the rolling element 43a on the separation inlet side does not enter the separation 45a, so the maximum rolling element load Q ｍａｘ On the other hand, as shown in FIG. 11, the separation length A ｎ If the distance between the rolling elements exceeds the distance between the rolling elements, the rolling element 43b penetrates into the flaking 45b, and the rolling element 43b that penetrates into the flaking 45b does not receive the load P. As a result, the maximum rolling element load Q received from the rolling element 43a ｍａｘ increases rapidly, and the separation 45b progresses rapidly.

[0053] Fig. 12 is a diagram illustrating the relationship between flaking length and operating time. In the test shown in Fig. 12, artificial scratches were made on the inner ring 41, and the rotating machine was operated with constant load and rotation speed, and the relationship between operating time and flaking length was measured. As shown in Fig. 12, it can be seen that when the flaking length exceeds the distance between the rolling elements, the flaking progresses rapidly. This indicates that the flaking length threshold A ｌｉｍ By making the distance between the rolling elements equal to the distance between the rolling elements, the bearing 40 can be replaced immediately before the flaking 45b begins to grow rapidly.

[0054] The bearing remaining life assessment method according to the first embodiment is not limited to that shown in Fig. 5. For example, the step of determining whether a parameter related to bearing deterioration is within a predetermined range (step S10) may be omitted. In this case, the rotating machine may be periodically precisely diagnosed, and if it is determined that flaking has occurred, the remaining life assessment by the bearing remaining life assessment device 200 may be initiated. Furthermore, the steps of determining whether or not initial flaking data and flaking length data are available (steps S21 and S51) are not essential steps, and the flaking length acquisition unit 251 may always acquire the estimated initial flaking length as the initial flaking length, or may always estimate the estimated flaking length as the flaking length.

[0055] As described above, the bearing remaining life assessment method according to the first embodiment is a method for predicting the remaining life of a rolling bearing used in a rotary machine, which has inner and outer raceways and rolling elements between the raceways, and includes the steps of: calculating an estimated flaking length, which is an estimate of the length of flaking on the raceways; and calculating the remaining life of the bearing based on the estimated flaking length and the predicted operating conditions of the rotary machine. The step of calculating the estimated flaking length includes the steps of calculating a maximum rolling element load from actual measurement data, calculating a maximum contact pressure from the maximum rolling element load, and calculating an estimated flaking length on the raceways from the maximum contact pressure on the raceways. This allows the remaining life of the bearing to be predicted according to the operating conditions of the rotary machine, thereby enabling the remaining life of the bearing to be appropriately predicted.

[0056] Furthermore, if the rotating machine is a generator, the actual measurement data may include the output of the generator. In this case, the remaining life of the bearing can also be appropriately predicted.

[0057] In a preferred embodiment, in the step of calculating the estimated length of separation on the raceway, the separation progression amount is estimated by multiplying the separation progression amount for each operating data by the occurrence frequency and summing them based on the relationship between the operating data of the rotating machine and the separation progression amount, and the estimated separation length is calculated by adding the separation progression amount to the previously obtained separation length.

[0058] In a preferred aspect, in the step of calculating the remaining life of the bearing, the operating status of the rotary machine is predicted based on past operating records of the rotary machine, thereby making it possible to more appropriately predict the remaining life of the bearing depending on the operating status of the rotary machine.

[0059] Furthermore, in the bearing remaining life assessment method according to the first embodiment, when an actual flaking length, which is the actual measurement of the flaking length on the raceway, is acquired, the remaining life of the bearing is calculated based on the actual flaking length and a prediction of the operating status of the rotating machine. If the actual flaking length has not been acquired, the method performs the steps of calculating an estimated flaking length and calculating the remaining life of the bearing based on the estimated flaking length and a prediction of the operating status of the rotating machine. As a result, when the actual flaking length is acquired, the remaining life of the bearing can be predicted based on the actual flaking length.

[0060] As described above, the bearing remaining life assessment device 200 according to the first embodiment is a bearing remaining life assessment method for predicting the remaining life of a rolling bearing used in a rotary machine, which has inner and outer raceways and rolling elements between the raceways. The device includes a peeling length acquisition unit that calculates an estimated peeling length, which is an estimate of the length of peeling on the raceways, and a remaining life calculation unit that calculates the remaining life of the bearing based on the estimated peeling length on the raceways and a prediction of the operating status of the rotary machine. The peeling length acquisition unit includes a maximum rolling element load calculation unit that calculates a maximum rolling element load from actual measurement data, a maximum contact pressure calculation unit that calculates a maximum contact pressure from the maximum rolling element load, and an estimated peeling length calculation unit that calculates an estimated peeling length on the raceways from the maximum contact pressure on the raceways. This allows the remaining life of the bearing to be predicted according to the operating status of the rotary machine, thereby enabling the remaining life of the bearing to be appropriately predicted.

[0061] 13 is a diagram illustrating a bearing remaining life assessment method according to a second embodiment. The bearing remaining life assessment method according to the second embodiment differs from the first embodiment in that in the step of calculating the maximum rolling element load (step S52), the maximum rolling element load is calculated from physical quantities measured by sensors 11a to 11c provided on housing 44 of bearing 40.

[0062] The sensors 11a to 11c measure physical quantities at the locations where they are installed. The physical quantities measured by the sensors 11a to 11c include at least one of a physical quantity related to vibration in at least one direction, displacement, and strain. The detection device 10 collects the physical quantities measured by the sensors 11a to 11c and transmits them to the bearing remaining life assessment device 200, whereby the peeling length acquisition unit 251 acquires the physical quantities measured by the sensors 11a to 11c. Note that the number and positions of the sensors shown in FIG. 13 are merely an example, and it is sufficient that multiple sensors are provided in the circumferential direction of the housing 44.

[0063] 14 is a diagram showing an example of a graph showing the relationship between the physical quantity measured by the sensor and the rolling element load. In the second embodiment, the maximum rolling element load calculation unit 252 calculates the rolling element load Q for each of the sensors 11a to 11c from the physical quantity measured by the sensor according to the relationship shown in the graph in FIG. １ ~Q ３ The relationship between the physical quantity measured by the sensor and the rolling element load shown in FIG. 14 is obtained in advance by FEM (Finite Element Method) analysis of the housing 44 and is stored in the storage unit 230.

[0064] Rolling element load Q for each of sensors 11a to 11c １ ~Q ３ is, for example, the radial displacement (radial displacement δ ｒ ) and axial displacement (axial displacement δ ａ ) Radial displacement δ ｒ and axial displacement δ ａ may be measured by the sensors 11a to 11c, or may be calculated from the physical quantities measured by the sensors 11a to 11c. ｒ and axial displacement δ ａ may be calculated by integrating the acceleration twice with respect to time, or may be calculated by integrating the velocity once with respect to time. ｒ and axial displacement δ ａThe rolling element load Q for each of the sensors 11a to 11c may be corrected from a transfer function previously determined by a striking test, taking into account the attenuation up to the installation point of the sensors 11a to 11c. １ ~Q ３ Generally, the rolling element load Q ｊ The radial displacement δ for each of the sensors is ｒ and axial displacement δ ａ and the radial displacement δ ｊｒ and axial displacement δ ｊａ It will be explained as follows.

[0065] Rolling element load Q ｊ is calculated by one of the following formulas (4) to (9) to calculate the radial displacement δ ｊｒ and axial displacement δ ｊａ The formulas (4) to (6) are formulas when the bearing 40 is a ball bearing. The formulas (7) to (9) are formulas when the bearing 40 is a roller bearing. In the formulas (4) to (9), L ｗｅ is the effective length of the rolling element 43, D ｗ is the diameter of the rolling element 43, α is the contact angle, and δ ｊｍａｘ is the displacement calculated by the following equation (10).

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073] The maximum rolling element load calculation unit 252 calculates the rolling element load Q ｊ The radial distribution of the rolling element load is estimated from the maximum rolling element load calculation unit 252. ｍａｘCalculate.

[0074] The bearing remaining life assessment method according to the second embodiment has been described above, but the sensor is not limited to a so-called contact sensor that measures at the installation position. The sensor may be a non-contact sensor, or one sensor may measure at multiple points.

[0075] As described above, in the bearing remaining life assessment method according to the second embodiment, in the step of calculating the maximum rolling element load, the actual measurement data includes physical quantities measured by sensors at multiple measurement points aligned circumferentially around the bearing, the rolling element load is calculated from the actual measurement data, and the maximum rolling element load is calculated from the rolling element load. Even in this case, the remaining life of the bearing can be appropriately predicted.

[0076] Furthermore, the physical quantity measured by the sensor may be a physical quantity related to vibration at the measurement point. In this case, the remaining life of the bearing can also be appropriately predicted.

[0077] The physical quantity measured by the sensor may be the displacement of the measurement point. In this case, the remaining life of the bearing can also be appropriately predicted.

[0078] The physical quantity measured by the sensor may be strain at the measurement point. In this case, the remaining life of the bearing can also be appropriately predicted.

[0079] Preferably, the rolling element load may be calculated from actual measurement data based on the relationship established by FEM analysis, thereby enabling a more accurate prediction of the remaining life of the bearing.

[0080] The rolling element load may also be calculated from the radial or axial displacement obtained from the value measured by a sensor. In this case, the remaining life of the bearing can also be appropriately predicted.

[0081] Furthermore, the physical quantity measured by the sensor may be the radial or axial displacement of the measurement point. In this case, the remaining life of the bearing can also be appropriately predicted.

[0082] Alternatively, the physical quantity measured by the sensor may be the radial acceleration or axial acceleration at the measurement point, and the radial displacement or axial displacement may be calculated from the radial acceleration or axial acceleration. In this case, the remaining life of the bearing can also be appropriately predicted.

[0083] Alternatively, the physical quantity measured by the sensor may be the radial strain or axial strain at the measurement point, and the radial displacement or axial displacement may be calculated from the radial strain or axial strain. In this case, the remaining life of the bearing can also be appropriately predicted.

[0084] Third Embodiment Fig. 15 is a plan view illustrating a bearing remaining life assessment method according to a third embodiment. More specifically, Fig. 15 is a vertical plan view of a wind power generator 100 according to the third embodiment. The bearing remaining life assessment method according to the third embodiment differs from the first embodiment in that in the step of calculating the maximum rolling element load (step S52), the maximum rolling element load is calculated from the wind direction and wind speed measured by an anemometer 12 provided on the wind power generator 100.

[0085] The anemometer 12 measures the direction and speed of the wind W directed toward the wind power generator 100. The detection device 10 collects the measured wind direction and wind speed and transmits them to the bearing remaining life assessment device 200, allowing the separation length acquisition unit 251 to acquire the wind direction and wind speed. Here, the wind direction refers to the angular difference θ between the azimuth angle of the wind W and the yaw rotation angle of the wind power generator 100. In the example of Fig. 15 , the separation length acquisition unit 251 acquires the angle between the direction of the wind W and the rotation axis of the rotor 30 as the angular difference θ when viewed in a vertical plane.

[0086] 16 is a diagram showing an example of a graph showing the relationship between wind speed and maximum rolling element load. In the second embodiment, the maximum rolling element load calculation unit 252 calculates the maximum rolling element load Q from the wind speed according to the relationship shown in the graph in FIG. ｍａｘ Here, the wind speed and the maximum rolling element load Q ｍａｘ In the example of FIG. 16, when the angle difference θ is θ1, the relationship between the wind speed and the maximum rolling element load Q ｍａｘFrom the relationship, the maximum rolling element load Q ｍａｘ The relationship between the wind speed and the maximum rolling element load shown in FIG. 16 is obtained in advance by measurement or analysis, and is stored in the storage unit 230.

[0087] As described above, in the bearing remaining life assessment method according to the third embodiment, the rotating machine is a wind power generator, and the measured data includes the direction and speed of the wind that the wind power generator receives. Even in this case, the remaining life of the bearing can be appropriately predicted.

[0088] (Fourth embodiment) The bearing remaining life assessment method according to the fourth embodiment differs from the first embodiment in that in the step of calculating the maximum rolling element load (step S52), the maximum rolling element load is calculated from a physical quantity related to the vibration of the bearing 40.

[0089] 17 is a diagram showing an example of a graph showing the relationship between a physical quantity related to vibration and a maximum rolling element load. In the fourth embodiment, the maximum rolling element load calculation unit 252 calculates the maximum rolling element load Q ｍａｘ The relationship between the physical quantity related to the vibration of the bearing 40 and the maximum rolling element load shown in FIG. 17 is obtained in advance by measurement or analysis, and is stored in the storage unit 230.

[0090] The vibration data is, for example, the amplitude of the rolling element passing vibration. The amplitude of the rolling element passing vibration refers to the amplitude of vibration generated by fluctuations in the bearing center position due to continuous changes in the rolling element position in the load direction caused by the revolution of the rolling element. When a large load is applied to the bearing 40, the amplitude of the rolling element passing vibration increases due to the inrush vibration of the load zone that receives the rolling element load, while when the load is small, the amplitude of the rolling element passing vibration decreases. Therefore, the maximum rolling element load Q ｍａｘ and the rolling element passing vibration, the maximum rolling element load Q ｍａｘ can be calculated.

[0091] The vibration data may be, for example, the amplitude of gear meshing vibration. The amplitude of gear meshing vibration refers to the amplitude of vibration generated by the impact on the gear tooth surfaces when the gears of the speed increaser 50 transmit meshing force to each other. When a large load is applied to the gears, the amplitude of gear meshing vibration increases, while when the load is small, the amplitude decreases. Therefore, the maximum rolling element load Q ｍａｘ and the gear meshing frequency, the maximum rolling element load Q ｍａｘ When the gear is a helical gear, radial vibrations tend to be smaller than when it is a spur gear, but axial vibrations occur, so it is preferable to measure not only radial vibrations but also axial vibrations.

[0092] As described above, in the bearing remaining life assessment method according to the fourth embodiment, the measured data includes physical quantities related to bearing vibration. Even in this case, the remaining life of the bearing can be appropriately predicted.

[0093] Furthermore, the physical quantity related to the vibration of the bearing includes the amplitude of the vibration caused by the rolling elements passing through the bearing. In this case, the remaining life of the bearing can also be appropriately predicted.

[0094] Furthermore, the physical quantity related to bearing vibration includes the amplitude of meshing vibration of gears in a rotary machine. In this case as well, the remaining life of the bearing can be appropriately predicted.

[0095] (Fifth embodiment) The bearing remaining life assessment method according to the fifth embodiment differs from the first embodiment in that in the step of calculating the maximum rolling element load (step S52), the maximum rolling element load is calculated from physical quantities at measurement points of multiple components connected to the main shaft 51.

[0096] In the fifth embodiment, one sensor is installed on the rotor 30 and one on the gearbox, and they measure physical quantities (phase, speed, and acceleration) related to vibrations in three axial directions. The detection device 10 collects the physical quantities measured by the sensors and transmits them to the bearing remaining life assessment device 200, and the peeling length acquisition unit 251 acquires the physical quantities measured by the sensors. Note that if the wind power generator 100 is a direct drive type, the sensor may be installed on the generator 60 instead of the gearbox. The sensor may also be installed directly on the main shaft 51. The sensor is not limited to a so-called contact sensor that performs measurements at the installation position, but may be a non-contact sensor, and one sensor may perform measurements at multiple points.

[0097] In the fifth embodiment, the maximum rolling element load calculation unit 252 calculates the maximum rolling element load from the physical quantity measured by the sensor. The relationship between the physical quantity measured by the sensor and the maximum rolling element load is obtained in advance by a motion analysis of the drive train of the main shaft 51 and is stored in the storage unit 230.

[0098] As described above, in the bearing remaining life assessment method according to the fifth embodiment, the rotating machine is a wind turbine generator. The measured data includes physical quantities related to vibrations in three mutually perpendicular directions at measurement points on multiple components connected to a main shaft on which the bearings are mounted. Even in this case, the remaining life of the bearings can be appropriately predicted.

[0099] Sixth Embodiment A bearing remaining life assessment method according to a sixth embodiment differs from the first embodiment in that the maximum rolling element load is calculated from a theory relating to bearing life. In the sixth embodiment, in the step of calculating the maximum rolling element load (step S52), the operating time T until flaking occurs is calculated. ａ Calculate the operating time T ａ Calculate the dynamic equivalent load P from the dynamic equivalent load P and calculate the radial load F ｒ and axial load F ａ Calculate the radial load F ｒ and axial load F ａ From the maximum rolling element load Q ｍａｘ Calculate.

[0100] (Operating time T ａTable 2 shows the operating time T of the bearings used in the gearbox 50. ａ The bearing life varies as the inverse of the rate of change ΔP of the dynamic equivalent load P raised to the power of a constant q. In addition, there is a certain relationship between the dynamic equivalent load P and the generator output G. From this, as shown in Table 2, it can be said that the larger the generator output G, the larger the rate of change ΔP of the dynamic equivalent load P. In Table 2, G ０ is the rated output (kW) of the generator. Also, as shown in equation (11), the rate of change ΔL of bearing life is expressed as the reciprocal of the rate of change ΔP of the dynamic equivalent load P raised to the power of a constant q. The value of q is 3 when the bearing 40 is a ball bearing, and 10 / 3 when it is a roller bearing. The example in Table 2 shows the case where the value of q is 10 / 3.

[0101]

[0102]

[0103] Operating time T ａ The data relating the output and time until the occurrence of the separation is obtained, and the operating time t ｋ Then, the operating time t for each range of the generator output G is calculated. ｋ is divided by the rate of change ΔL of bearing life, the operating time t for each range of the weighted generator output G is calculated. ｋＬ As a result, the operating time t ｋＬ The total operating time is T ａ can be calculated.

[0104]

[0105] (Dynamic equivalent load P) The dynamic equivalent load P is calculated by simultaneously solving equations (13) and (14), which are modified life calculation formulas in accordance with ISO 281:2007, and is used to calculate the operating time T ａ In formula (13), L ｎｍｈ is the modified rated life of the bearing, a １ is the reliability coefficient, a ＩＳＯ is the life correction coefficient, ω is the bearing ring rotation speed, C ｒmeans the dynamic load rating of the bearing, and P means the dynamic equivalent load. Also, q is 3 for ball bearings and 10 / 3 for roller bearings. In equation (14), C ｕ is the fatigue load limit, κ is the viscosity ratio of the lubricating oil, e ｃ is the contamination factor. Fatigue load limit C ｕ can be calculated from the specifications of the bearing 40. The viscosity ratio κ is calculated based on the reference kinematic viscosity v １ It is expressed as the ratio of the operating viscosity v to the reference kinematic viscosity v １ can be calculated from the specifications and rotational speed of the bearing 40, and the operating viscosity v is calculated based on the operating temperature of the lubricating oil actually used and information on the kinematic viscosity of the lubricating oil at 40°C and 100°C. The operating temperature of the lubricating oil may be obtained by monitoring, or may be estimated based on the design information of the equipment. The kinematic viscosity of the lubricating oil at 40°C and 100°C can be obtained by checking the specifications of the lubricating oil used. The contamination coefficient e ｃ can be calculated using a formula corresponding to the filtration performance of the filter, based on the specifications of the bearing 40 and the viscosity ratio κ. If the filtration performance can be confirmed from the filter element specifications, the corresponding formula is used. If the filtration performance cannot be confirmed but a monitoring device such as a particle counter is installed, the filtration performance can be estimated from the detected values. If the filtration performance is unknown, the formula corresponding to the contamination code compliant with IEC 61400-4 Ed.1.0:2012 can be used.

[0106]

[0107]

[0108] (Radial load F ｒ , axial load F ａ ) Radial load F ｒ and axial load F ａ is calculated based on the dynamic equivalent load P from equations (15) and (16). In equations (15) and (16), e is F ｒ and F ａ The load ratio is , and X and Y are load factors determined by the load ratio e. Here, in the case of a pure radial load condition without axial load, the radial load F ｒcan be the dynamic equivalent load P. Also, in the case of a pure axial load condition without a radial load, the axial load F ａ can be taken as the dynamic equivalent load P.

[0109]

[0110]

[0111] The load ratio e can be estimated by the following method.

[0112] Fig. 18 is a diagram for explaining an example of a method for estimating the load ratio e. As shown in Fig. 18, a housing 44 of the bearing 40 is provided with a plurality of sensors 14r in the radial direction and a plurality of sensors 14a in the axial direction. In the example of Fig. 18, four sensors 14r and four sensors 14a are provided at equal intervals in the radial direction, but this is merely an example. The sensors 14r and 14a are single-axis sensors, and each sensor measures a vector quantity S related to vibration in the radial direction. ｒ１ ~S ｒ４ and the vector quantity S related to the vibration in the axial direction ａ１ ~S ａ４ Here, the vector quantity related to the vibration is, for example, a phase vector, a velocity vector, an acceleration vector, etc., associated with the vibration of the measurement object. In the case of FIG. 18, a resultant vector S of the vector quantities related to the measured vibration in the radial direction is ｒ is calculated by equation (17), and the resultant vector S of the vector quantity related to the measured axial vibration is ａ is calculated by equation (18), and the resultant vector S ｒ The magnitude of the resultant vector S ａ The load ratio e can be estimated by taking the ratio of the magnitudes of

[0113]

[0114]

[0115]

[0116] 19 is a diagram for explaining a different example of a method for estimating the load ratio e. As shown in FIG. 19, a plurality of three-axis sensors 14t are provided in the radial direction on the housing 44 of the bearing 40, and the sensors 14t respectively measure vector quantities S related to vibrations in the radial direction and the axial direction. ｒ１ ~S ｒ４ , S ａ１ ~S ａ４ A plurality of sensors 14a are provided in the axial direction. In the example of FIG. 19, four sensors 14t are provided at equal intervals in the radial direction, but this is merely an example. In the case of FIG. 19, as in the case of FIG. 18, the resultant vector S of the vector quantity related to the measured radial vibration is ｒ is calculated by equation (17), and the resultant vector S of the vector quantity related to the measured axial vibration is ａ is calculated by equation (18), and the resultant vector S ｒ The magnitude of the resultant vector S ａ The load ratio e can be estimated by taking the ratio of the magnitudes of

[0117] The method for estimating the load ratio e is not limited to the method shown in Figures 18 and 19. For example, if the maximum load position is known, the load ratio e may be estimated using only the radial and axial vibrations measured in the direction of the maximum load position. Furthermore, as shown in the fifth embodiment, the load ratio e may be estimated by measuring a physical quantity related to the vibration of the main shaft 51 or a member connected to the main shaft.

[0118] (Maximum rolling element load Q ｍａｘ ) Maximum rolling element load Q ｍａｘ is calculated from the dynamic equivalent load P using equations (20) and (21). In equations (20) and (21), Z is the number of rolling elements, and α is the contact angle. ｒ is the radial integral, J ａis the axial integral. The radial and axial integrals are coefficients defined in Sjovall, H., The load distribution within ball and roller bearings under given external radial and axial load, Tek Tidskr, Mek., Vol.h, No.9(1933).

[0119]

[0120]

[0121] If the load is not pure radial or pure axial, the radial integral J ｒ and the axial integral J ａ can be calculated from the load ratio e.

[0122] In the case of pure radial load conditions, the radial integral J ｒ and the axial integral J ａ can be calculated using equations (22) to (24). Equation (22) is the equation when the bearing 40 is a cylindrical or tapered roller bearing. Equation (23) is the equation when the bearing 40 is a spherical roller bearing. Equation (24) is the equation when the bearing 40 is a ball bearing. In equations (22) to (24), f(ε) is a function of the load factor ε, but the radial load F ｒ and the bearing clearance and the specifications of the bearing 40. In addition, the load factor ε and the radial integral J ｒ The relationship between the load factor ε and the radial integral J is theoretically determined. ｒ can be calculated.

[0123]

[0124]

[0125]

[0126] The load factor ε can be estimated by the following method.

[0127] Fig. 20 is a diagram for explaining an example of a method for estimating the load factor ε. As shown in Fig. 20, a plurality of sensors 15 are provided in the radial direction on the housing 44 of the bearing 40. In the example of Fig. 20, eight sensors 15 are provided at equal intervals in the radial direction, but this is merely an example. The sensors 14r and 14a are single-axis sensors, and each measures a vector quantity S related to vibration in the radial direction. ｒ１ ~S ｒ８ Here, the physical quantity measured by the sensor 15 is, for example, a phase, a speed, an acceleration, etc. The maximum load position and the boundary position between the load zone and the non-load zone are estimated from the circumferential distribution of the physical quantity obtained by the sensor 15. In the example of FIG. 20, the vector quantity S related to the vibration is ｒ１ The magnitude of the vector quantity S related to the vibration ｒ１ ~S ｒ８ Since it is the largest among these, the vector quantity S related to vibration ｒ１ In the example of FIG. 20, the measurement position of the vector quantity S ｒ４ ~S ｒ６ Since the value is close to 0, the vector quantity S related to the vibration ｒ４ ~S ｒ６ Assuming that the measurement position is within the non-load zone, the vector quantity S related to the vibration ｒ３ , S ｒ７ The measurement position is estimated as the boundary position between the loaded and unloaded zones. This allows the angle ψ between the direction from the center of rotation toward the maximum load position and the boundary between the loaded and unloaded zones to be calculated. In the case of Figure 20, the load factor ε can be estimated from the calculated angle ψ using equation (25).

[0128]

[0129] Note that the method for estimating the load factor ε is not limited to the method shown in FIG. 20 . For example, if the maximum load position is known, the load factor ε can be estimated by measuring the vector quantity related to vibration at the maximum load position using a triaxial sensor. More specifically, at the maximum load position, the vector quantity related to vibration in the radial direction and the vector quantity related to vibration in a direction forming an angle of 90° between the radial direction and the rotational direction are simultaneously measured. In this case, the vector quantities measured in the two directions are added to calculate a resultant vector at the maximum load position, and the angle between the resultant vector at the maximum load position and the radial direction at the maximum load position is defined as angle ψ, whereby the load factor ε can be estimated using equation (25).

[0130] As described above, in the bearing remaining life assessment method according to the sixth embodiment, in the step of calculating the maximum rolling element load, the actual measurement data includes physical quantities at a plurality of measurement points aligned circumferentially of the bearing, the rolling element load is calculated from the actual measurement data, and the maximum rolling element load is calculated from the rolling element load and the life modification coefficient. Even in this case, the remaining life of the bearing can be appropriately predicted.

[0131] In addition, in the bearing remaining life assessment method according to the sixth embodiment, in the step of calculating the maximum rolling element load, the measured data includes physical quantities at a plurality of measurement points arranged circumferentially around the bearing, the rolling element load is calculated from the measured data, and the maximum rolling element load is calculated from the rolling element load, the load ratio between the radial load and the axial load, and the load factor. Even in this case, the remaining life of the bearing can be appropriately predicted.

[0132] The load ratio may also be estimated from the vector quantities related to radial vibration and axial vibration measured simultaneously at multiple measurement points spaced equally around the circumference of the bearing. In this case, the remaining life of the bearing can also be estimated appropriately.

[0133] The load ratio may also be estimated from the ratio between the physical quantity related to the radial vibration and the physical quantity related to the axial vibration at the maximum load position. In this case, the remaining life of the bearing can also be appropriately predicted.

[0134] The load factor may also be calculated from measurement data relating to the rotating machine. In this case, the remaining life of the bearing can also be appropriately predicted.

[0135] Alternatively, the load factor may be estimated by estimating the maximum load position and the boundary between the loaded and unloaded zones from the circumferential distribution of physical quantities related to radial vibrations measured simultaneously at multiple measurement points arranged at equal intervals around the circumference of the bearing. In this case, the remaining life of the bearing can also be appropriately predicted.

[0136] The load factor may also be estimated from the angle between the radial direction at the maximum load position and a vector quantity obtained by adding together a vector quantity related to vibrations in the axial direction and a direction perpendicular to the radial direction at the maximum load position. In this case, the remaining life of the bearing can also be appropriately predicted.

[0137] The figures used above are conceptual diagrams for qualitatively explaining the present disclosure, and are not intended to be limiting. Furthermore, while the above-described embodiment is an example of a preferred implementation of the present disclosure, the present disclosure is not limited thereto, and various modifications can be made without departing from the spirit and scope of the present disclosure.

[0138] DESCRIPTION OF SYMBOLS 1 Bearing remaining life assessment system 10 Detection device 11 Data collection unit 11a to 11c Sensor 12 Wind direction and speed meter 14a, 14r, 14t Sensor 15 Sensor 30 Rotor 31 Hub 32 Blade 40 Bearing 41 Inner ring 42 Outer ring 43, 43a, 43b Rolling element 44 Housing 45a, 45b Flaking 50 Gearbox 51 Main shaft 60 Generator 61 Generator shaft 70 Nacelle 80 Tower 90 Foundation 100 Wind power generator 200 Bearing remaining life assessment device 210 Input unit 220 Output unit 230 Memory unit 240 Communication unit 250 Control unit 251 Flaking length acquisition unit 252 Maximum rolling element load calculation unit 253 Maximum contact pressure calculation unit 254 Estimated separation length calculation unit 255 Remaining life calculation unit NW Network W Wind

Claims

1. A bearing remaining life assessment method for predicting the remaining life of a rolling bearing used in a rotating machine, which has inner and outer raceways and rolling elements between the two raceways, comprising the steps of: calculating an estimated peeling length, which is an estimate of the peeling length of the raceway; and calculating the remaining life of the bearing based on the estimated peeling length and a prediction of the operating status of the rotating machine, wherein the step of calculating the estimated peeling length comprises the steps of: calculating a maximum rolling element load from actual measurement data; calculating a maximum contact pressure from the maximum rolling element load; and calculating the estimated peeling length of the raceway from the maximum contact pressure of the raceway.

2. A bearing remaining life assessment method as described in claim 1, wherein, in the step of calculating the maximum rolling element load, the actual measurement data includes physical quantities measured by a sensor at a plurality of measurement points arranged in the circumferential direction of the bearing, the rolling element load is calculated from the actual measurement data, and the maximum rolling element load is calculated from the rolling element load.

3. A bearing remaining life assessment method according to claim 2, wherein the physical quantity measured by the sensor is a physical quantity related to vibration at the measurement point.

4. A bearing remaining life assessment method according to claim 2, wherein the physical quantity measured by the sensor is the displacement of the measurement point.

5. A bearing remaining life assessment method according to claim 2, wherein the physical quantity measured by the sensor is strain at the measurement point.

6. A bearing remaining life assessment method according to any one of claims 2 to 5, wherein the rolling element load is calculated from the measured data, based on a relationship determined by FEM analysis.

7. A bearing remaining life assessment method according to claim 2, wherein the rolling element load is calculated from radial displacement or axial displacement.

8. A bearing remaining life assessment method according to claim 7, wherein the physical quantity measured by the sensor is a radial displacement or an axial displacement of the measurement point.

9. A bearing remaining life assessment method as described in claim 7, wherein the physical quantity measured by the sensor is the radial acceleration or axial acceleration of the measurement point, and the radial displacement or the axial displacement is calculated from the radial acceleration or the axial acceleration.

10. A bearing remaining life assessment method as described in claim 7, wherein the physical quantity measured by the sensor is radial strain or axial strain at the measurement point, and the radial displacement or axial displacement is calculated from the radial strain or axial strain.

11. The bearing remaining life assessment method according to claim 1, wherein the rotating machine is a generator, and the measured data includes an output of the generator.

12. The bearing remaining life assessment method according to claim 1, wherein the rotating machine is a wind power generator, and the measured data includes a direction and a speed of the wind received by the wind power generator.

13. A bearing remaining life assessment method according to claim 1, wherein the measured data includes a physical quantity related to vibration of the bearing.

14. A bearing remaining life assessment method according to claim 13, wherein the physical quantity relating to the vibration of the bearing includes an amplitude of vibration of the rolling elements passing through the bearing.

15. A bearing remaining life assessment method according to claim 13, wherein the physical quantity relating to the vibration of the bearing includes an amplitude of meshing vibration of gears of the rotating machine.

16. A bearing remaining life assessment method as set forth in claim 1, wherein the actual measurement data includes physical quantities related to vibrations in three mutually perpendicular directions at measurement points on a plurality of components connected to a main shaft on which the bearing is mounted.

17. A bearing remaining life assessment method as described in claim 1, wherein, in the step of calculating the maximum rolling element load, the actual measurement data includes physical quantities at a plurality of measurement points arranged in a circumferential direction of the bearing, the rolling element load is calculated from the actual measurement data, and the maximum rolling element load is calculated from the rolling element load and a life correction coefficient.

18. A bearing remaining life assessment method as described in claim 1 or 17, wherein, in the step of calculating the maximum rolling element load, the measured data includes physical quantities at a plurality of measurement points arranged in the circumferential direction of the bearing, the rolling element load is calculated from the measured data, and the maximum rolling element load is calculated from the rolling element load, the load ratio between the radial load and the axial load, and the load factor.

19. A bearing remaining life assessment method as set forth in claim 18, wherein the load ratio is estimated from a vector quantity related to radial vibration and a vector quantity related to axial vibration measured simultaneously at a plurality of measurement points arranged at equal intervals around the circumference of the bearing.

20. A bearing remaining life assessment method as set forth in claim 18, wherein the load ratio is estimated from the ratio between a physical quantity relating to radial vibration and a physical quantity relating to axial vibration at the maximum load position.

21. A bearing remaining life assessment method as set forth in claim 18, wherein the load factor is calculated from measurement data relating to the rotating machine.

22. A bearing remaining life assessment method as set forth in claim 21, wherein the load factor is estimated by estimating the maximum load position and the position of the boundary between the loaded zone and the unloaded zone from the circumferential distribution of physical quantities related to radial vibration measured simultaneously at a plurality of measurement points arranged at equal intervals around the circumference of the bearing.

23. A bearing remaining life assessment method as set forth in claim 21, wherein the load factor is estimated from the angle between the radial direction at the maximum load position and a resultant vector of a vector quantity related to vibration in the radial direction at the maximum load position and a vector quantity related to vibration in the axial direction and in a direction perpendicular to the radial direction at the maximum load position.

24. A bearing remaining life assessment method as described in claim 1, wherein in the step of calculating an estimated length of flaking on the raceway, the amount of flaking progression is estimated by multiplying the amount of flaking progression for each piece of operating data by the frequency of occurrence and summing up the results based on the relationship between the operating data of the rotating machine and the amount of flaking progression, and the estimated length of flaking is calculated by adding the amount of flaking progression to the previously obtained flaking length.

25. A bearing remaining life assessment method as set forth in claim 1, wherein in the step of calculating the latest remaining life of the bearing, the operating condition of the rotating machine is predicted based on the past operating record of the rotating machine.

26. A bearing remaining life assessment method, which, when an actual flaking length, which is an actual measurement of the flaking length of the raceway, is obtained, calculates the remaining life of the bearing based on the actual flaking length and a prediction of the operating status of the rotating machine, and, when the actual flaking length is not obtained, performs the bearing remaining life assessment method described in claim 1.

27. A bearing remaining life assessment method for predicting the remaining life of a rolling bearing used in a rotating machine, which has inner and outer raceways and rolling elements between the two raceways, comprising: a peeling length acquisition unit that calculates an estimated peeling length, which is an estimate of the peeling length of the raceway; and a remaining life calculation unit that calculates the remaining life of the bearing based on a prediction of the estimated peeling length of the raceway and the operating status of the rotating machine, wherein the peeling length acquisition unit comprises: a maximum rolling element load calculation unit that calculates a maximum rolling element load from actual measurement data; a maximum contact pressure calculation unit that calculates a maximum contact pressure from the maximum rolling element load; and an estimated peeling length calculation unit that calculates an estimated peeling length of the raceway from the maximum contact pressure of the raceway.

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