Bearing raceway flaking propagation analysis method, flaking analysis device, and program

Abstract

To provide a separation progression analysis method of a bearing in which prediction accuracy is improved in comparison to a conventional technique.SOLUTION: A separation progression analysis method acquires the presence / absence of separation of a bearing ring and the shape of a separation part by separation status acquisition means, calculates a rolling element load acting on a rolling element when the rolling element passes through an outlet part of the separation part of the bearing ring by considering the shape of the progressing separation part on the basis of at least the acquired shape of the separation part, specifications of the rolling bearing and the operation condition of the rolling bearing, calculates the progression speed of the separation considering the shape of the progressing separation part on the basis of the rolling element load in the outlet part of the separation part, and calculates the relation between the elapsed time and the shape of the separation part on the basis of the progression speed of the separation. The progression speed of the separation is calculated on the basis of the surface pressure with respect to the outlet part of the separation part derived from a relief amount of the rolling element in the axial direction generated according to the shape of the separation part.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a method for analyzing the propagation of flaking in a raceway of a bearing, a flaking analysis device, and a program. [Background technology]

[0002] Conventionally, bearings have been used in various devices. One example of a device that uses bearings is a wind power generation device. In the case of large bearings such as those used in wind power generation devices, installation and replacement are not easy, so even if an abnormality occurs in a part, the device may continue to operate for a certain period of time with that part.

[0003] For example, when a bearing rotates under load, the raceway surfaces of the inner and outer rings and the rolling surfaces of the rolling elements are constantly subjected to repeated loads, which can cause minute scale-like damage called spalling due to fatigue of the material. The life of a bearing is generally defined as the time until it becomes unusable due to spalling. Even if spalling occurs while the bearing is in operation, operation is continued by suppressing the operating load, such as limiting the amount of power generated, until replacement parts can be procured and installed. However, if the replacement time is delayed and spalling progresses rapidly within the bearing, even if the abnormality is initially minor, the spalled pieces may get caught in parts such as gears or the inner and outer rings may crack. As a result, in the worst case, there is a risk of causing fatal damage such as the entire device stopping. In addition, if such damage occurs, maintenance work that stops the device for a long period of time may be required.

[0004] To avoid such a situation, for example, Patent Document 1 discloses an analysis method for predicting the expansion and time of micro-flaking after its occurrence so that equipment can be used safely for a certain period of time after the occurrence of micro-flaking. Also, Patent Document 2 discloses a method for predicting the remaining life of rolling bearings using a fracture mechanics technique. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6844764 [Patent Document 2] JP 2017-219469 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the method of Patent Document 1, prediction is made under the assumption that the axial width of the initial flaking is the same as the axial length of the rolling element. Therefore, if the axial width of the flaking is different from the axial length of the rolling element, the prediction accuracy may decrease, i.e., the remaining life may tend to become shorter. In addition, Patent Document 2 does not take into account the shape of the flaking that changes with operation, which results in an error in the flaking growth rate.

[0007] In view of the above problems, an object of the present invention is to provide a method for analyzing the propagation of flaking in a bearing, which has improved prediction accuracy compared to conventional methods. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention has the following configuration: A method for analyzing flaking propagation, which predicts the propagation of flaking in a raceway of a rolling bearing used in a rotary machine, the rolling bearing having inner and outer raceways and rolling elements between the inner and outer raceways, comprises: a step of acquiring information on the presence or absence of flaking on the raceway and the shape of the flaked portion by a flaking state acquiring means; calculating a rolling element load acting on the rolling element when the rolling element passes through an outlet portion of the flaking portion of the raceway, based on at least the acquired shape of the flaking portion, specifications of the rolling bearing, and operating conditions of the rolling bearing, taking into account the shape of the progressing flaking portion; calculating a propagation speed of the flaking, taking into account the shape of the progressing flaking portion, based on a rolling element load at an outlet of the flaking portion; calculating a relationship between an elapsed time and a shape of the peeled portion based on the propagation speed of the peeling; having The propagation speed of the flaking is calculated based on the contact pressure at the outlet of the flaking portion, which is derived from the amount of relief of the rolling element in the axial direction that occurs in accordance with the shape of the flaking portion.

[0009] Another aspect of the present invention has the following configuration: A flaking propagation analysis device for predicting the propagation of flaking in a raceway of a rolling bearing used in a rotary machine, the rolling bearing having inner and outer raceways and rolling elements between the inner and outer raceways, comprising: a flaking condition acquisition means for acquiring the presence or absence of flaking of the raceway and the shape of the flaked portion; a load calculation unit that calculates a rolling element load acting on the rolling element when the rolling element passes through an outlet portion of the flaking portion of the raceway, based on at least the acquired shape of the flaking portion, specifications of the rolling bearing, and operating conditions of the rolling bearing, taking into account the shape of the progressing flaking portion; a propagation speed calculation unit that calculates a propagation speed of the flaking portion, taking into consideration a shape of the flaking portion as it progresses, based on a rolling element load at an outlet of the flaking portion; a calculation unit that calculates a relationship between an elapsed time and a shape of the peeled portion based on the propagation speed of the peeling; Equipped with The propagation speed of the flaking is calculated based on the contact pressure at the outlet of the flaking portion, which is derived from the amount of relief of the rolling element in the axial direction that occurs in accordance with the shape of the flaking portion.

[0010] Another aspect of the present invention has the following configuration. That is, a program comprising: On the computer, a step of acquiring information on the presence or absence of flaking on a raceway of the rolling bearing and the shape of the flaked portion by a flaking state acquiring means; calculating a rolling element load acting on the rolling elements of the rolling bearing when the rolling elements pass through an outlet portion of the flaking portion of the raceway, based on at least the acquired shape of the flaking portion, specifications of the rolling bearing, and operating conditions of the rolling bearing, taking into account the shape of the progressing flaking portion; calculating a propagation speed of the flaking, taking into account the shape of the progressing flaking portion, based on a rolling element load at an outlet of the flaking portion; calculating a relationship between an elapsed time and a shape of the peeled portion based on the propagation speed of the peeling; Run the command, The propagation speed of the flaking is calculated based on the contact pressure at the outlet of the flaking portion, which is derived from the amount of relief of the rolling element in the axial direction that occurs in accordance with the shape of the flaking portion. Effect of the Invention

[0011] According to the present invention, it is possible to provide a method for analyzing the propagation of flaking in a bearing, with improved prediction accuracy compared to conventional methods. [Brief description of the drawings]

[0012] [Figure 1] 1 is a block diagram showing a schematic configuration of a delamination propagation analysis device according to an embodiment of the present invention; [Diagram 2] FIG. 1 is a diagram for explaining the progression of peeling. [Diagram 3] FIG. 11 is a graph for explaining an analysis result obtained by using a conventional analysis method. [Figure 4] FIG. 4 is a diagram for explaining roller relief and the generation of concentrated surface pressure. [Diagram 5] FIG. 1 is a diagram for explaining a dynamic FEM analysis taking into account the inertia of rolling elements. [Figure 6] An exploded view showing an example of the results of a dynamic FEM analysis. [Figure 7] FIG. 11 is a graph illustrating an analysis result obtained by using the analysis method according to the embodiment of the present invention. [Figure 8] 3 is a flowchart of a process according to an embodiment of the present invention. [Figure 9A] FIG. 1 is a conceptual diagram showing the magnitude of the rolling element load before flaking occurs. [Figure 9B] FIG. 1 is a conceptual diagram showing the change in the magnitude of the rolling element load after flaking occurs. [Figure 10A] FIG. 4 is an enlarged view showing the relationship between the flaking portion and the rolling element. [Figure 10B]FIG. 4 is an enlarged view showing the relationship between the flaking portion and the rolling element. [Figure 11A] FIG. 4 is an enlarged view of a main portion showing a rolling element passing through the outlet of the flaking portion. [Figure 11B] A diagram showing stress distribution based on FEM analysis taking into account the shape of the peeled part. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment for carrying out the present invention will be described with reference to the drawings. Note that the embodiment described below is one embodiment for explaining the present invention, and is not intended to be interpreted as limiting the present invention, and all configurations described in each embodiment are not necessarily essential configurations for solving the problems of the present invention. In addition, in each drawing, the same components are given the same reference numbers to indicate their correspondence.

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method and an apparatus for analyzing the propagation of flaking in a raceway of a rolling bearing according to an embodiment of the present invention will be described in detail below with reference to the drawings.

[0015] [Device configuration] As shown in Fig. 1, the raceway crack propagation analysis device 1 of this embodiment analyzes a cracked portion that has occurred on an inner or outer raceway (i.e., the inner ring 11 or the outer ring 12) of a rolling bearing 10 installed in a machine equipment 20. The peeling propagation analysis device 1 includes a control device 30 and an output device 40. The peeling propagation analysis device 1 is connected to the machine equipment 20, which is the object of analysis, via data transmission means 22.

[0016] The peeling state acquisition means 21 acquires the presence or absence and shape of flaking of the rolling bearing 10. The peeling state acquisition means 21 may be installed in advance on the mechanical equipment 20, or may be configured to be detachable from the mechanical equipment 20 and be configured to be attached to the mechanical equipment 20 during analysis. The calculation processing unit 31 receives the signal acquired by the peeling state acquisition means 21 via the data transmission means 22, and performs signal processing to determine the presence or absence of flaking in the raceway of the rolling bearing 10 and to analyze the progress of flaking. In this embodiment, the subject that executes the analysis processing according to this embodiment is shown as the calculation processing unit 31, but each processing step may be divided into separate processing units. The control unit 32 drives and controls the mechanical equipment 20. The part that controls the operation of the mechanical equipment 20 may be a different device, and in that case, the control unit 32 of the control device 30 may be configured to acquire parameters related to the control from that device. The storage unit 33 stores various data and programs related to the analysis, analysis results, and the like. The output device 40 is made up of a monitor, an alarm, etc., and outputs the results of the flaking growth analysis and the remaining life of the rolling bearing 10.

[0017] The rolling bearing 10 has an inner ring 11 that is fitted onto the rotating shaft of the mechanical equipment 20, an outer ring 12 that is fitted into a housing 14 or the like, a plurality of rolling elements 13 arranged so as to be able to roll between the inner ring 11 and the outer ring 12, and a retainer (not shown) that holds the rolling elements 13 so that they can roll freely.

[0018] The peeling condition acquisition means 21 may be selected arbitrarily depending on the method of acquiring the peeling condition. For example, the peeling condition acquisition means 21 may be a fiberscope or a camera to directly observe the shape of the peeled portion. Alternatively, a vibration sensor, a load sensor, a displacement sensor, or the like may be used as the peeling condition acquisition means 21. Furthermore, the peeling condition acquisition means 21 may detect the temperature, the amount (concentration) of iron powder in the lubricating oil, or the like. The vibration sensor, the load sensor, and the displacement sensor are fixed in the load zone of the housing 14 to which the outer ring 12, which is the fixed ring of the rolling bearing 10, is attached. Furthermore, the peeling condition acquisition means 21 is not limited to being constituted by one acquisition means, and may be constituted by a combination of multiple types of acquisition means.

[0019] The calculation processing unit 31 and the control unit 32 of the control device 30 are configured, for example, by a microcomputer (an IC chip, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a DSP (Digital Signal Processor), etc.), and each process described below is executed by a program of this microcomputer.

[0020] The control device 30 stores the analysis results of the flaking part of the rolling bearing 10 analyzed by the calculation processing unit 31 in the storage unit 33, outputs the operation of the mechanical equipment 20 to the control unit 32, and feeds back a control signal for driving the mechanical equipment 20 according to the analysis result to the operation of the mechanical equipment 20 (safety operation such as reducing the rotation speed). Furthermore, the control device 30 sends the analysis result to the output device 40 by a data transmission means 34 using a wired or wireless network. The storage unit 33 is composed of a volatile or non-volatile storage device, and is configured to be able to store and refer to various programs and data according to this embodiment. The storage unit 33 may be composed of, for example, a RAM (Random Access Memory), a ROM (Read Only Memory), a HDD (Hard Disk Drive), etc., and its configuration is not particularly limited.

[0021] The output device 40 displays the analysis results of the rolling bearing 10 on a monitor or the like in real time. Furthermore, if an abnormality is detected, an alarm such as a light or buzzer may be used to alert the operator to the abnormality. Furthermore, the signal data transmission means 22 only needs to be able to accurately send and receive signals from the peeling condition acquisition means 21, so it may be wired or wireless in consideration of a network.

[0022] [Analysis method] The analysis method according to the present embodiment will be described below. First, a conventional method to be compared with the analysis method according to the present embodiment and improvements thereon will be described.

[0023] FIG. 2 is a diagram for explaining an example of the progress of flaking occurring on the raceway surface of the inner ring 11, which is a rotating ring constituting the rolling bearing 10. FIG. 2(a) is an external perspective view of only the inner ring 11 of the rolling bearing 10. Here, the progress of flaking occurring at position 200 will be explained. Here, an example of a self-aligning roller bearing in which the rolling elements are barrel-shaped is shown. The flaking occurs on the raceway surface where contact occurs between the inner ring 11 and the rolling elements 13, and progresses with the use of the rolling bearing 10. Images 210 to 240 shown in FIG. 2(b) to (e) show the progress of the flaking. In the images 210 to 240, the left-right direction corresponds to the axial direction, and the up-down direction corresponds to the circumferential direction. As shown in the images 210 to 240, as the flaking progresses, its range (axial and circumferential directions) gradually increases.

[0024] Fig. 3 is a graph for explaining the correspondence between the results of predictions of flaking growth by a conventional method and the actual results of flaking growth. Here, the above-mentioned Patent Document 1 and Patent Document 2 are used for explanation as conventional methods. In Fig. 3, the vertical axis indicates the length [mm] of the flaking in the rotation direction (circumferential direction) of the rotating ring, and the horizontal axis indicates the passage of time [h] from the occurrence of flaking. The reference numbers of the plots shown in the graph correspond to the reference numbers of each image in Fig. 2. Furthermore, d indicates the pitch between the rollers, which are the rolling elements.

[0025] Here, the measurement results of two tests are compared with the predicted results using the conventional method. In each test, flaking caused by the rollers occurred on the raceway surface of the inner ring, and the general state was similar to that shown in each image in Figure 2. Line 301 shows the predicted results of flaking progression based on the conventional method of Patent Document 1. Line 302 shows the predicted results of flaking progression based on the conventional method of Patent Document 2.

[0026] FIG. 4 is a diagram for explaining the occurrence of axial relief of rolling elements 13 (barrel-shaped rollers in this example) and concentrated surface pressure when flaking occurs. As shown in FIG. 4(a), when flaking occurs on the raceway surface, the rolling elements 13 move in the axial direction (hereinafter referred to as "relief"). The amount of relief varies depending on the state (shape, etc.) of the flaking. When the rolling elements 13 are in a state where relief has occurred, as the rotating ring and the rolling elements 13 rotate, when the rolling elements 13 escape from the flaking region, concentrated surface pressure is generated around the boundary between the flaking region and other regions.

[0027] For example, as shown in Fig. 2, in the early stage of flaking (e.g., image 210), the flaking progresses in the direction of the rotation axis. At such a stage, the rolling element 13 escapes as explained in Fig. 4(a), and further, concentrated contact pressure is generated when escaping from the flaking. For example, the method of Patent Document 2 does not take into account the shape of the flaking related to such concentrated contact pressure, and therefore has the side effect of underestimating the flaking progress speed, as shown by the straight line 302 in Fig. 3.

[0028] In addition, the method of Patent Document 1 calculates the balance of forces taking into account the shape of the flaking, and calculates the load of the rolling element when it escapes from the flaking area. However, since it does not provide a motion analysis that takes into account the inertia of the rolling element, it is not possible to predict the phenomenon in which the rolling element escapes and the concentrated surface pressure gradually increases as the flaking progresses. Therefore, as shown by the line 301 in Figure 3, there is an aspect that the flaking growth speed is overestimated.

[0029] Therefore, the analysis method according to the present embodiment provides an analysis method that takes into account the relief of the rolling element and the concentrated surface pressure that accompanies the change in the shape of the flaking. In the present embodiment, a dynamic FEM (Finite Element Method) analysis is used to identify the parameters of the relief amount of the rolling element and the concentrated surface pressure, and these are reflected in the analysis results.

[0030] Fig. 5 is a diagram for explaining dynamic FEM analysis that takes into account the inertia of the rolling elements, used in this embodiment. Fig. 5(a) is an external perspective view of a self-aligning roller bearing as rolling bearing 10. Fa indicates the axial load on rolling bearing 10, and Fr indicates the radial load on rolling bearing 10. Fig. 5(b) is an image of a flaking region on the raceway surface of the rotating ring in region 500 in Fig. 5(a). In the image of Fig. 5(b), the left-right direction corresponds to the rotation direction of the rotating ring, and the up-down direction corresponds to the rotation axis direction.

[0031] FIG. 5(c) is a model diagram in which the region 500 is enlarged. The rolling elements 13 (in this example, rollers) are disposed between the outer ring 12 and the inner ring 11. A flaking region 501 is formed on the raceway surface of the inner ring 11. In this embodiment, the surface pressure due to contact between the respective members is derived by performing dynamic FEM analysis. The gradation shown around the rolling elements 13 in FIG. 5(c) indicates the surface pressure derived by the dynamic FEM analysis, and the darker the color, the higher the surface pressure. Here, the surface pressure due to contact between the rolling elements 13 and the outer ring 12 and between the rolling elements 13 and the inner ring 11 is shown.

[0032] Figure 6 is a diagram for explaining the transition of surface pressure and the occurrence of concentrated surface pressure based on dynamic FEM analysis. Here, an example is shown in which the rolling bearing 10 is operating in a state in which flaking has occurred. The transition from Figure 6(a) to Figure 6(f) is shown in the order of Figure 6(a) to Figure 6(f), and the surface pressure is shown in gradation, similar to Figure 5(c).

[0033] FIG. 6(a) shows a state where the rolling element 13 is located outside the flaking region. In this state, the rolling element does not escape. FIG. 6(b) shows a state immediately before the rolling element 13 enters the flaking region. FIG. 6(c) shows a state where the rolling element 13 escapes from a part of the flaking region (the narrow region on the right in the figure). In this case, it is assumed that the rolling element 13 escapes to the wide region on the left in the figure, so the surface pressure during the escape is relatively suppressed. Due to the occurrence of the escape, the surface pressure between the outer ring 12 and the rolling element 13 is also suppressed. FIG. 6(d) and FIG. 6(e) show a state where the rolling element 13 has further escaped from the flaking region from the state of FIG. 6(d). At this time, the surface pressure between the rolling element 13 and the inner ring 11 gradually increases. The surface pressure and the contact area between the rolling element 13 and the outer ring 12 also change. FIG. 6(f) shows a state where the rolling element 13 has completely escaped from the flaking region. At this time, the rolling element 13 loses the relief that occurred in the wide region on the left side of the figure, and a concentrated surface pressure is generated around the boundary between the flaking region and the other region.

[0034] In this embodiment, the parameters of the axial relief amount and concentrated surface pressure are derived based on the results of the dynamic FEM analysis and used for prediction. A more detailed derivation method will be described later together with a processing flow.

[0035] Fig. 7 is a semi-logarithmic graph for explaining the correspondence between the results of prediction of flaking progression by the method of this embodiment, the results of prediction of flaking progression by the conventional method, and the actual progression results. Here, the conventional method will be explained using Patent Documents 1 and 2, as in Fig. 2. In Fig. 7, the vertical axis indicates the length [mm] of flaking in the rotation direction (circumferential direction) of the rotating ring, and the horizontal axis indicates the passage of test time [h]. The reference numbers of the plots shown in the graph correspond to the reference numbers of each image in Fig. 2. Also, d indicates the pitch between the rollers, which are the rolling elements.

[0036] Here, the measurement results of two tests are compared with the prediction results by the method of this embodiment and the conventional method. In each test, flaking caused by the rollers occurred on the raceway surface of the inner ring, and the general state is similar to that shown in each image in FIG. 2. Curve 701 shows the prediction result of flaking growth based on the conventional method of Patent Document 1. Curve 702 shows the prediction result of flaking growth based on the conventional method of Patent Document 2. Curve 703 shows the prediction result of flaking growth based on the method of this embodiment.

[0037] 7, the prediction result (curve 703) by the method according to this embodiment can predict the timing of occurrence of peeling closer to the actual timing than the prediction result (curve 701) by the conventional method. Furthermore, the prediction result (curve 703) by the method according to this embodiment more accurately expresses the degree of change (curve) indicating the progress of actual peeling than the prediction result (curve 702) by the conventional method. Therefore, the analysis method according to this embodiment can predict the progress of actual peeling more accurately than the conventional method.

[0038] [Processing flow] 8 is a flowchart of the analysis process according to this embodiment. This process is executed by the control device 30 of the peeling progress analysis device 1, and may be realized, for example, by the calculation processing unit 31 included in the control device 30 reading out from the storage unit 33 a program for implementing the process according to this embodiment and executing it. This process may be started when the rolling bearing 10 starts operating, or may be started based on a user's instruction while the rolling bearing 10 is operating. In addition, this processing flow may be configured to be executed periodically.

[0039] In S801, the control device 30 monitors flaking by acquiring the presence or absence and shape of flaking using the flaking condition acquisition means 21. For example, if the flaking condition acquisition means 21 is a fiberscope, the raceway surface is directly observed. Note that the monitoring of flaking is not limited to direct observation, and it may be indirectly monitored based on an index defined based on the specifications and operating conditions of the rolling bearing 10.

[0040] In S802, the control device 30 determines whether or not peeling has been detected based on the information acquired by the peeling state acquisition means 21. The criteria for determining peeling here may be predefined. For example, it may be determined whether or not a peeled portion has occurred in the early stage prior to the state of FIG. 2(b). If peeling has been detected (YES in S802), the process of the control device 30 proceeds to S803. On the other hand, if peeling has not been detected (NO in S802), the process of the control device 30 returns to S801 and continues monitoring.

[0041] In S803, the control device 30 identifies the shape of the flaking that has occurred, the specifications of the rolling bearing 10, and the operating conditions of the rolling bearing 10 as input parameters, and inputs them into the calculation program according to this embodiment. The shape of the flaking is identified based on information acquired by the flaking state acquisition means 21, and may include, for example, the area, circumferential length, and axial length of the flaking. The specifications of the rolling bearing 10 may be defined in advance and stored in the storage unit 33 or the like. The operating conditions may be set in advance, or may be set based on information obtained from a sensor (not shown) or the like. Other information related to the flaking may be used, and may include, for example, vibration, temperature, and the amount (concentration) of iron powder in the lubricant.

[0042] The bearing load, which is one of the operating conditions, may be a constant bearing load, a directly measured bearing load, or a bearing load indirectly determined from the power generation output or the rotational torque of the shaft. Also, a pre-assumed operating load pattern may be input. As the rotation speed, the current rotation speed may be input assuming that the engine will continue to operate at the current rotation speed, or, if the operating speed is to be decelerated when an initial flaking portion is observed, the decelerated rotation speed may be input.

[0043] In S804, the control device 30 calculates the load F of the rolling element 13 passing through the outlet of the flaking portion that has occurred in the rolling bearing 10. The load may be calculated based on the indicators input in S803 (e.g., the shape of the initial flaking, the specifications of the rolling bearing, the operating conditions, etc.). Here, the load F of the rolling element 13 is calculated by a calculation method in accordance with ISO / TS16281. More specifically, as shown in FIG. 9A, the axial load P pushes the inner ring 11 and thus the multiple rolling elements 13 are pushed simultaneously, and the load F of the rolling element 13 at the outlet of the flaking portion is calculated by solving the balance of forces.

[0044] As shown in FIG. 9A, when the rolling bearing 10 rotates with a radial bearing load acting on the inner ring 11 due to the axial load P, the load range Q area A rolling element load F0 having a magnitude according to the position of the rolling element 13 is generated on each of the rolling elements 13 positioned at the position.

[0045] On the other hand, the load zone Q where the contact pressure between the rolling element 13 and the raceway surface of the inner ring 11 is maximum area Suppose that flaking occurs on the raceway surface of the inner ring 11 at the center. In this case, as shown in FIG. 9B, the rolling element 13 passing through the flaked portion 15 cannot support the bearing load, and falls within the load zone Q shown in FIG. 9A. area The bearing load is supported by a smaller number of rolling elements 13 than the rolling elements 13 in the other load zones Q areaAn increased rolling element load F1 is applied to the rolling element 13 located at the flaked portion. Therefore, by solving the force balance equation in Fig. 9B using the relationship of the rolling element load F0 of the rolling element 13 in Fig. 9A, the rolling element load F at the exit of the flaked portion when the initial flaked portion has occurred can be calculated. Specifically, the rolling element loads F0 and F1 are found by a calculation method conforming to ISO / TS16281. Moreover, the rolling element load F1 of the rolling element 13 passing through the flaked portion 15 is calculated assuming that no load is applied.

[0046] In addition, the load area Q area The initial flaking portion that occurs in the center expands in the circumferential direction of the raceway surface (the direction in which the rolling elements 13 pass in the example shown in this embodiment). Normally, as a rolling element load is repeatedly applied to a crack 15a (see Figs. 10A, 10B, 11A, and 11B) at the exit of the flaking portion 15, the crack 15a gradually grows in the circumferential direction as indicated by the arrow in Fig. 11B, and then a flaking piece 15b of a predetermined length is generated in stages. Then, as shown in Fig. 10B, when the circumferential length A of the flaking portion 15 reaches a length where two adjacent rolling elements 13 enter at the same time (circumferential length A = pitch distance d between the rolling elements), the rolling element load F1 at the exit of the flaking portion 15 increases and is applied.

[0047] In S805, the control device 30 performs a crack growth analysis that takes into account the progressing peeling shape based on the rolling element load calculated in S803, and calculates the crack growth speed as the speed at which the peeling expands (peeling growth speed V). The calculation method here uses the concentrated surface pressure parameters identified by the results of the dynamic FEM analysis as described above.

[0048] The crack growth behavior in fatigue phenomena is governed by the linear fracture mechanics parameter K (stress intensity factor), which is expressed by the crack length and the stress acting on the crack. In the region where the crack grows stably, the variation range ΔK (stress intensity factor variation range) of the stress intensity factor K and the crack growth rate da / dN per stress cycle have a double logarithmic linear relationship, which is known as the Paris law shown below.

[0049] da / dN=C(ΔK)m (1) ΔK: Stress concentration factor fluctuation range C, m: experimental constants

[0050] Therefore, in this embodiment, by substituting ΔK into the above formula (1), the crack growth rate can be calculated as the delamination growth rate V. In this embodiment, taking into account the concentrated surface pressure described above, ΔK is defined using the following formula (2).

[0051]

number

[0052] P0: Maximum surface pressure of the rolling element (concentrated surface pressure) a: Circumferential crack length F c : Proportional coefficient π: Pi

[0053] The proportionality factor F c can be obtained in advance from the results of static FEM analysis. More specifically, the stress distribution at the tip of the crack at the edge when the roller comes into contact with the flaking edge is calculated by static FEM analysis, and F is calculated from the stress distribution. c It is possible to derive in advance the stress intensity factor fluctuation width ΔK for obtaining . FIG. 11B shows the concept of stress distribution around the contact position between the rolling element and the crack site. In this embodiment, the concentrated surface pressure P0 is calculated from the relief amount and substituted for P0 in the above formula (2), thereby reflecting the change in the delamination growth rate in the remaining life estimation result. Note that the delamination growth rate (crack growth rate) V may be formulated in advance using the J integral value that is generally used in fracture mechanics. In this case, too, the formulation is performed using the concentrated surface pressure based on the relief amount of the rolling element calculated from the dynamic FEM analysis.

[0054] In S806, the control device 30 applies bearing specifications such as the number of rolling elements 13 and operating conditions such as rotational speed to the obtained crack growth rate da / dN per stress cycle, and calculates the relationship between the operating time and the spalling size A from theoretical calculations using the following equation (3).

[0055] A = A0 + da / dN × n (3) A0: Circumferential length of the peeled area at the time of observation n: The number of times that the rolling element loads the exit part of the flaking part within the load range

[0056] Then, based on the calculated relationship, the control device 30 calculates the remaining time until the flaking shape input in S803 changes to a predetermined flaking shape (circumferential length in the above example) as the remaining life of the rolling bearing 10. The predetermined flaking shape may be specified in advance or may be received in this step. If it is predictable that the flaking will expand rapidly before the predetermined flaking shape is reached, that is, if it is predictable that the crack growth rate will increase rapidly, the remaining time may be calculated to be the time before the rapid expansion. This makes it possible to treat the time before the behavior of the rolling bearing 10 may suddenly deteriorate as the remaining life.

[0057] In S807, the control device 30 outputs the result calculated in S806. Then, this processing flow ends. The output method here is not particularly limited, and the analysis result may be visually displayed on a monitor, which is the output device 40, or may be audibly output by an alarm. In addition, the analysis result may be output to an external device so that the parameters of the analysis result can be reused in other processing. Note that the analysis processing according to this embodiment may end together with a notification when the calculated remaining life falls below a predetermined threshold value, or may be continued while the rolling bearing 10 continues to operate.

[0058] 4 may be performed by calculating in advance the maximum length of flaked portion assumed as the bearing life for each rolling bearing specification under predetermined operating conditions, and storing the calculation result data in a table in the storage unit 33. This makes it possible to omit some processing during analysis and reduce the processing load.

[0059] As described above, this embodiment makes it possible to analyze the propagation of flaking in a bearing with improved prediction accuracy compared to conventional methods.

[0060] As described above, the present specification discloses the following: (1) A method for analyzing flaking propagation that predicts the propagation of flaking in a raceway of a rolling bearing used in a rotary machine, the rolling bearing having inner and outer raceways and rolling elements between the inner and outer raceways, the method comprising the steps of: a step of acquiring information on the presence or absence of flaking on the raceway and the shape of the flaked portion by a flaking state acquiring means; calculating a rolling element load acting on the rolling element when the rolling element passes through an outlet portion of the flaking portion of the raceway, based on at least the acquired shape of the flaking portion, specifications of the rolling bearing, and operating conditions of the rolling bearing, taking into account the shape of the progressing flaking portion; calculating a propagation speed of the flaking, taking into account the shape of the progressing flaking portion, based on a rolling element load at an outlet of the flaking portion; calculating a relationship between an elapsed time and a shape of the peeled portion based on the propagation speed of the peeling; Equipped with A method for analyzing the propagation of flaking in the raceway of a rolling bearing, wherein the propagation rate of the flaking is calculated based on the surface pressure at the outlet of the flaking portion, which is derived from the amount of axial escape of the rolling element that occurs in accordance with the shape of the flaking portion. This configuration enables bearing flaking propagation analysis with improved prediction accuracy compared to conventional methods. In particular, it is possible to predict flaking propagation with greater accuracy by taking into account concentrated surface pressure based on the axial movement (relief) of the rolling elements that occurs depending on the shape of the flaked area.

[0061] (2) The method for analyzing flaking propagation in a raceway of a rolling bearing according to claim 1, wherein the clearance of the rolling element is determined by dynamic FEM (Finite Element Method) analysis. According to this configuration, it is possible to appropriately derive the clearance of the rolling elements from the results of the dynamic FEM analysis.

[0062] (3) The propagation speed of the peeling is

number

[0063] da / dN: Crack growth rate ΔK: Stress concentration factor fluctuation range C, m: experimental constants P0: Maximum surface pressure of the rolling element (concentrated surface pressure) a: Circumferential crack length F c : Proportional coefficient π: Pi The method for analyzing the propagation of peeling in a raceway of a rolling bearing according to claim 1 or 2, wherein the peeling propagation rate is calculated using the following formula: With this configuration, it is possible to more accurately predict the progression of flaking by taking into account the concentrated surface pressure based on the axial movement (escape) of the rolling element that occurs depending on the shape of the flaking area.

[0064] (4) A method for analyzing the propagation of flaking in a raceway of a rolling bearing according to any one of (1) to (3), further comprising a step of outputting the remaining time until a specified shape of the flaked portion is reached as a remaining life. According to this configuration, by treating the remaining time until the desired peeling shape is achieved as the life, it is possible to predict the time until an arbitrary peeling shape is achieved.

[0065] (5) A flaking propagation analysis device for predicting the propagation of flaking in a raceway of a rolling bearing used in a rotary machine, the rolling bearing having inner and outer raceways and rolling elements between the inner and outer raceways, comprising: a flaking condition acquisition means for acquiring the presence or absence of flaking of the raceway and the shape of the flaked portion; a load calculation unit that calculates a rolling element load acting on the rolling element when the rolling element passes through an outlet portion of the flaking portion of the raceway, based on at least the acquired shape of the flaking portion, specifications of the rolling bearing, and operating conditions of the rolling bearing, taking into account the shape of the progressing flaking portion; a propagation speed calculation unit that calculates a propagation speed of the flaking portion, taking into consideration a shape of the flaking portion as it progresses, based on a rolling element load at an outlet of the flaking portion; a calculation unit that calculates a relationship between an elapsed time and a shape of the peeled portion based on the propagation speed of the peeling; Equipped with A device for analyzing the propagation of flaking in the raceway of a rolling bearing, wherein the propagation rate of the flaking is calculated based on the surface pressure at the outlet of the flaking portion, which is derived from the amount of axial relief of the rolling element that occurs in accordance with the shape of the flaking portion. This configuration enables bearing flaking propagation analysis with improved prediction accuracy compared to conventional methods. In particular, it is possible to predict flaking propagation with greater accuracy by taking into account concentrated surface pressure based on the axial movement (relief) of the rolling elements that occurs depending on the shape of the flaked area.

[0066] (6) To the computer: a step of acquiring information on the presence or absence of flaking on a raceway of the rolling bearing and the shape of the flaked portion by a flaking state acquiring means; calculating a rolling element load acting on the rolling elements of the rolling bearing when the rolling elements pass through an outlet portion of the flaking portion of the raceway, based on at least the acquired shape of the flaking portion, specifications of the rolling bearing, and operating conditions of the rolling bearing, taking into account the shape of the progressing flaking portion; calculating a propagation speed of the flaking, taking into account the shape of the progressing flaking portion, based on a rolling element load at an outlet of the flaking portion; calculating a relationship between an elapsed time and a shape of the peeled portion based on the propagation speed of the peeling; Run the command, The program calculates the propagation speed of the flaking based on the surface pressure at the outlet of the flaking portion, which is derived from the amount of axial escape of the rolling element that occurs in accordance with the shape of the flaking portion. This configuration enables bearing flaking propagation analysis with improved prediction accuracy compared to conventional methods. In particular, it is possible to predict flaking propagation with greater accuracy by taking into account concentrated surface pressure based on the axial movement (relief) of the rolling elements that occurs depending on the shape of the flaked area. [Explanation of symbols]

[0067] 1…Delamination progress analysis device 10...Roller bearing 11. Inner circle 12…Outer ring 13...Rolling element 14. Housing 20...Machinery and equipment 22...Data transmission means 30...Control device 31...Computation processing unit 32...Control section 33...Storage section 34...Data transmission means 40...Output device

Claims

1. A flaking propagation analysis method for predicting propagation of flaking in a raceway of a rolling bearing used in a rotary machine, the rolling bearing having inner and outer raceways and rolling elements between the inner and outer raceways, comprising: a step of acquiring information on the presence or absence of flaking on the raceway and the shape of the flaked portion by a flaking state acquiring means; calculating a rolling element load acting on the rolling element when the rolling element passes through an outlet portion of the flaking portion of the raceway, based on at least the acquired shape of the flaking portion, specifications of the rolling bearing, and operating conditions of the rolling bearing, taking into account the shape of the progressing flaking portion; calculating a propagation speed of the flaking, taking into account the shape of the progressing flaking portion, based on a rolling element load at an outlet of the flaking portion; calculating a relationship between an elapsed time and a shape of the peeled portion based on the propagation speed of the peeling; Equipped with A method for analyzing the propagation of flaking in the raceway of a rolling bearing, wherein the propagation rate of the flaking is calculated based on the surface pressure at the outlet of the flaking portion, which is derived from the amount of axial escape of the rolling element that occurs in accordance with the shape of the flaking portion.

2. 2. The method for analyzing flaking propagation in a raceway of a rolling bearing according to claim 1, wherein the amount of escape of the rolling element is determined by dynamic FEM (Finite Element Method) analysis.

3. The propagation speed of the peeling is [0010] da / dN: crack growth rate ΔK: Stress concentration factor fluctuation range C, m: experimental constants P ０ : Maximum surface pressure of rolling elements (concentrated surface pressure) a: Circumferential crack length F ｃ : proportionality coefficient π: pi The method for analyzing the propagation of flaking in a raceway of a rolling bearing according to claim 1 or 2, wherein the flaking propagation is calculated using the following formula:

4. 3. The method for analyzing flaking propagation in a raceway of a rolling bearing according to claim 1, further comprising the step of outputting a remaining time until a predetermined shape of the flaked portion is reached as a remaining life.

5. A flaking propagation analysis device for predicting propagation of flaking in a raceway of a rolling bearing used in a rotary machine, the rolling bearing having inner and outer raceways and rolling elements between the inner and outer raceways, comprising: a flaking condition acquisition means for acquiring the presence or absence of flaking of the raceway and the shape of the flaked portion; a load calculation unit that calculates a rolling element load acting on the rolling element when the rolling element passes through an outlet portion of the flaking portion of the raceway, based on at least the acquired shape of the flaking portion, specifications of the rolling bearing, and operating conditions of the rolling bearing, taking into account the shape of the progressing flaking portion; a propagation speed calculation unit that calculates a propagation speed of the flaking portion, taking into consideration a shape of the flaking portion as it progresses, based on a rolling element load at an outlet of the flaking portion; a calculation unit that calculates a relationship between an elapsed time and a shape of the peeled portion based on the propagation speed of the peeling; Equipped with A device for analyzing the propagation of flaking in the raceway of a rolling bearing, wherein the propagation rate of the flaking is calculated based on the surface pressure at the outlet of the flaking portion, which is derived from the amount of axial relief of the rolling element that occurs in accordance with the shape of the flaking portion.

6. On the computer, a step of acquiring information on the presence or absence of flaking on a raceway of the rolling bearing and the shape of the flaked portion by a flaking state acquiring means; calculating a rolling element load acting on the rolling elements of the rolling bearing when the rolling elements pass through an outlet portion of the flaking portion of the raceway, based on at least the acquired shape of the flaking portion, specifications of the rolling bearing, and operating conditions of the rolling bearing, taking into account the shape of the progressing flaking portion; calculating a propagation speed of the flaking, taking into account the shape of the progressing flaking portion, based on a rolling element load at an outlet of the flaking portion; calculating a relationship between an elapsed time and a shape of the peeled portion based on the propagation speed of the peeling; Run the command, The program calculates the propagation speed of the flaking based on the surface pressure at the outlet of the flaking portion, which is derived from the amount of axial escape of the rolling element that occurs in accordance with the shape of the flaking portion.

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