Method for renovating bearing

Abstract

This method for renovating a bearing includes an acquisition step (step S121) for acquiring a maximum standard clearance value of a bearing to be renovated, a clearance measuring step (step S122) for measuring the clearance of the bearing before disassembly, a removal step (step S104) for removing a fatigue layer of at least one of an outer ring and an inner ring of the bearing, and a calculation step (step S123) for calculating, on the basis of the maximum standard clearance value and the clearance, a limit removal amount of the fatigue layer in the removal step, the limit removal amount being the upper limit of the total amount of the fatigue layer to be removed from the mutually-opposing surfaces of the outer ring and the inner ring, wherein, in the removal step, the fatigue layer is removed within the range of the limit removal amount.

Description

Bearing refurbishment method

[0001] This disclosure relates to a method for regenerating bearings.

[0002] A regeneration technology for bearings used in various types of machinery has been proposed.

[0003] Patent Document 1 discloses a method for regenerating a rolling bearing, which involves forming rolling grooves in a pair of bearing members that move relative to each other, and interposing rolling elements between these rolling grooves. This regeneration method consists of a step of removing a thickness from the surface of the rolling grooves that corresponds to approximately 10% to 20% of the diameter of the rolling elements, and a step of forming a hardened layer on the rolling groove surface corresponding to the removed thickness. Patent Document 1 also discloses that the hardened layer is made of hard chrome plating.

[0004] Japanese Patent Application Publication No. 2007-120632

[0005] However, the hardened layer formed in the rolling grooves is made of a different type of steel than the original, and the fatigue layer that receives the load is different from the original, so the performance as a bearing cannot be guaranteed. In addition, the plating layer has poor adhesion and is prone to peeling, so it may peel off when subjected to load. Therefore, it is conceivable to regenerate the bearing by removing the fatigue layer from the rolling surface of a fatigued bearing. However, if too much is removed, the load condition will change, which may affect the bearing life.

[0006] The present invention aims to provide a bearing regeneration method that can provide a regenerated bearing that maintains its original bearing performance while suppressing the impact of changes in load conditions on bearing life.

[0007] One aspect of the present invention is a method for regenerating a bearing, comprising: an acquisition step of obtaining the maximum clearance specification of a bearing to be regenerated; a clearance measurement step of measuring the clearance of the bearing before disassembly; a removal step of removing the fatigue layer from at least one of the outer ring and inner ring of the bearing; and a calculation step of calculating the limit removal amount, which is the upper limit of the total amount of the fatigue layer removed from the mutually opposing surfaces of the outer ring and inner ring, based on the maximum clearance specification and the clearance amount, wherein in the removal step, the fatigue layer is removed within the range of the limit removal amount.

[0008] According to the present invention, it is possible to provide a reconditioned bearing that maintains its original bearing performance while suppressing the impact of changes in load conditions on bearing life.

[0009] Figure 1 is a schematic diagram of a reuse decision support system and reuse decision support device for assisting in the determination of whether a bearing can be reused according to Embodiment 1. Figure 2 is a schematic diagram showing the state in which the output voltage value of the raceway surface of the outer ring of a rolling bearing is measured by a probe. Figure 3 is a flowchart showing the procedure of the reuse decision support method performed by the reuse decision support device according to Embodiment 1. Figure 4 is a decision map stored in the map storage unit, which includes the relationship between the output voltage value of the bearing and the fatigue degree of the bearing. Figure 5 is a diagram showing an example of the operation image of the reuse decision support system. Figure 6 is a flowchart showing the procedure of the reuse decision support method performed by the reuse decision support device according to Embodiment 2. Figure 7 is an image diagram of the process for obtaining the correction value in the second mode of Embodiment 2, where (A) is an image diagram of the outer ring of the bearing and (B) is an image diagram of the inner ring of the bearing. Figure 8 is a graph showing the calculation image of the correction value according to the raceway diameter. Figure 9 is an image diagram of the reuse decision support method performed by the reuse decision support device according to Embodiment 3, where (A) is an image diagram of the outer ring of a bearing made of bearing steel, and (B) is an image diagram of the inner ring of a bearing made of bearing steel. Figure 10 is an image diagram of the reuse decision support method performed by the reuse decision support device according to Embodiment 3, where (A) is an image diagram of the outer ring of a bearing made of carburized steel, and (B) is an image diagram of the inner ring of a bearing made of carburized steel. Figure 11 is an image diagram of the reuse decision support method performed by the reuse decision support device according to Embodiment 4. Figure 12 is an image diagram of the reuse decision support method performed by the reuse decision support device according to Embodiment 5. Figure 13 is an image diagram of the reuse decision support method performed by the reuse decision support device according to Embodiment 6, where (A) is an image diagram of a fixed outer ring and there is a non-trailing surface as well as a racing surface on the raceway surface, and (B) is an image diagram of a fixed outer ring and there is no non-trailing surface on the raceway surface.Figure 14 is an image diagram of the reuse decision support method performed by the reuse decision support device according to Embodiment 6, where (A) is an image diagram of a rotating paddle wheel and there are not only a running surface but also a non-running surface on the track surface, and (B) is an image diagram of a rotating paddle wheel and there is no non-running surface on the track surface. Figure 15 is a conceptual diagram showing that the calculated E-dance characteristic V, as displayed on the decision map, is an outlier. Figure 16 is a flowchart showing the procedure of the reuse decision support method performed by the reuse decision support device according to Embodiment 7. Figure 17 is a conceptual diagram of the display unit recommending remeasurement. Figure 18 is a schematic configuration diagram of the reuse decision support system and reuse decision support device according to Embodiment 8. Figure 19 is a flowchart showing the procedure of the reuse decision support method performed by the reuse decision support device according to Embodiment 8. Figure 20 is a flowchart showing the procedure of the reuse decision support method performed by the reuse decision support device according to Embodiment 9. Figure 21 is a schematic configuration diagram of the reuse decision support system and reuse decision support device according to Embodiment 10. Figure 22 is a flowchart showing the procedure of the reuse decision support method performed by the reuse decision support device according to Embodiment 10. Figure 23 is a schematic configuration diagram of the reuse decision support system and reuse decision support device according to Embodiment 11. Figure 24 is a flowchart showing the procedure of the fatigue layer removal method performed by the reuse decision support device according to Embodiment 12. Figure 25 is a flowchart showing the procedure of the regeneration method for the inner ring of a bearing made of bearing steel performed by the reuse decision support device according to Embodiment 12. Figure 26 is an image diagram of the process of the reuse decision support method performed by the reuse decision support device according to Embodiment 12, and is an image diagram of the inner ring of a bearing made of bearing steel. Figure 27 is a flowchart showing the procedure of the regeneration method for a bearing made of carburized steel performed by the reuse decision support device according to Embodiment 12, and is a flowchart showing the procedure for the regeneration of the inner ring, which is a raceway ring that receives rotational load. Figure 28 is an image diagram of the process of the bearing regeneration method performed by the reuse decision support device according to Embodiment 12, and is an image diagram of the inner ring of the bearing in the flowchart of Figure 27.Figure 29 is a flowchart showing the procedure for the regeneration method of a bearing made of bearing steel performed by the reuse decision support device according to Embodiment 12, and is a flowchart showing the procedure for the regeneration of the outer ring, which is a raceway ring with a load area. Figure 30 is an image diagram of the process for the bearing regeneration method performed by the reuse decision support device according to Embodiment 12, and is an image diagram of the outer ring of the bearing in the flowchart of Figure 29. Figure 31 is a flowchart showing the procedure for the regeneration method of a bearing made of carburized steel performed by the reuse decision support device according to Embodiment 12, and is a flowchart showing the procedure for the regeneration of the outer ring, which is a raceway ring with a load area. Figure 32 is an image diagram of the process for the bearing regeneration method performed by the reuse decision support device according to Embodiment 12, and is an image diagram of the outer ring of the bearing in the flowchart of Figure 31. Figure 33 is a schematic diagram showing the relationship between the maximum clearance specification, the clearance amount before removal processing, and the allowance for removal processing of the outer and inner rings combined. Figure 34 is a flowchart showing the procedure for calculating the limit removal amount based on the clearance amount, performed by the reuse decision support device according to Embodiment 13. Figure 35 is an explanatory diagram relating to Embodiment 14, showing a schematic diagram of a single-row tapered roller bearing, where (A) is a cross-sectional view of the single-row tapered roller bearing and (B) is a schematic representation of the raceway surface of the single-row tapered roller bearing. Figure 36 is a flowchart showing the procedure for calculating the limit removal amount performed by the reuse decision support device according to Embodiment 14, which calculates the limit removal amount based on the assembly width value when the bearing is a single-row tapered roller bearing. Figure 37 is an explanatory diagram relating to Embodiment 15, a graph showing an example of the relationship between surface depth and hardness gradient image for a bearing made of carburized steel. Figure 38 is a flowchart showing the procedure for calculating the limit removal amount performed by the reuse decision support device according to Embodiment 16, which calculates the limit removal amount based on past removal history. Figure 38 is a table showing the history image of fatigue layer removal processing stored in the data storage unit according to the procedure in the flowchart of Figure 38. Figure 40 is a graph showing the transition line, which is the relationship between surface depth and fatigue parameters in surface fatigue, created in Embodiment 17. Figure 41 is a graph showing examples of multiple transition lines illustrating the relationship between surface depth and fatigue parameters in surface fatigue, as created in Embodiment 18.

[0010] Preferred embodiments of the bearing regeneration method according to the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to these embodiments, and if there are multiple embodiments, they may be constructed by combining each embodiment. Furthermore, the components in the embodiments include those that are easily conceivable by those skilled in the art, those that are substantially identical, and those within a so-called equivalent range.

[0011] (Embodiment 1) Figure 1 is a schematic diagram of a reuse decision support system 1 and a reuse decision support device 10 that assist in determining whether a bearing can be reused according to Embodiment 1. As shown in Figure 1, the reuse decision support system 1 includes a reuse decision support device 10, which is the main part of the reuse decision, and a data storage unit (storage unit) 50 that stores the data necessary for the decision. The reuse decision support device 10 includes a measurement signal input unit 20, a measurement signal acquisition unit 30, and a fatigue determination unit 40. The reuse decision support system 1 and the reuse decision support device 10 assist the user in determining whether a bearing can be reused by presenting the results of the reuse decision. A reuse decision is to determine whether a bearing can be used or not, and specifically includes determining whether the bearing is "can be used continuously (can be used as is without repair)", "requires repair (can be used after repair)", or "cannot be used (cannot be repaired, requires replacement, or must be discarded)".

[0012] The measurement signal input unit 20 includes a probe 21, a switch 22, and an input unit 23. The probe 21 induces eddy currents in the bearing by applying an AC magnetic field to the bearing to be judged by passing an excitation current through a built-in coil (not shown), and outputs the voltage value generated in the coil by these eddy currents as a measurement signal S01 (analog signal). That is, the probe 21 inputs the output voltage value (measurement signal S01) obtained by eddy current measurement to the input unit 23. The output voltage value obtained by eddy current measurement corresponds to the impedance characteristics of the bearing. The X and Y components of the output voltage value, i.e., X voltage and Y voltage, are converted by multiplying the resistance R and reactance X components in the impedance Z = R + jX by the current value I, respectively, and are expressed as X voltage = R × I and Y voltage = X × I. The switch 22 transmits a measurement control signal S02 (digital signal) that switches the start and end of acquiring the measurement signal of the output voltage value detected by the probe 21. The input unit 23 receives the measurement signal S01 from the probe 21 and the measurement control signal S02 from the switch 22, and converts the analog signals into digital signals.

[0013] The probe 21 induces eddy currents by applying an alternating magnetic field to the bearing to be measured (for example, the outer ring, inner ring, or rolling elements of a rolling bearing), and non-destructively measures the metal structure (for example, the amount of retained austenite) by detecting the voltage change generated in the coil due to these eddy currents. Examples of bearing surfaces to be measured include the raceway surface, outer surface, and axial end faces of the outer ring, the raceway surface, inner surface, and axial end faces of the inner ring, and the circumferential surfaces of the rolling elements.

[0014] When the probe 21 is in contact with the surface of the bearing to be measured, the measurement signal S01 is always transmitted to the input unit 23. However, as will be described later, the input unit 23 does not always acquire the measurement signal S01, and the acquisition of the measurement signal S01 is switched on or off based on the state of the measurement control signal S02 transmitted by the switch 22.

[0015] Switch 22 is a component that can be pressed by the user. For example, when switch 22 is pressed (ON state), a measurement control signal S02 that switches the start and end of acquiring the measurement signal S01 is transmitted to the input unit 23, and when switch 22 is not pressed (OFF state), the measurement control signal S02 is not transmitted to the input unit 23. For example, when the measurement control signal S02 is transmitted to the input unit 23, the measurement signal S01 is acquired by the input unit 23 and measurement is performed, resulting in a measurement execution state. On the other hand, when the measurement control signal S02 is not transmitted to the input unit 23, the measurement signal S01 is not acquired by the input unit 23 and measurement is not performed, resulting in a measurement non-execution state.

[0016] The input unit 23 is connected to the probe 21 via a cable 24 (see Figure 2), which will be described later. The input unit 23 includes an A / D converter (not shown) that receives a measurement signal S01 of the bearing output voltage value detected by the probe 21, and a digital input / output unit (not shown) that is connected to a switch 22 and receives a measurement control signal S02 transmitted by the switch 22. The measurement signal S01 and the measurement control signal S02, converted into digital signals, are transmitted to the measurement signal acquisition unit 30 via the input unit 23.

[0017] The measurement signal acquisition unit 30 includes a measurement switching unit 31 and a data holding unit 32. The measurement switching unit 31 switches between a measurement execution state in which the measurement signal S01 is taken into the fatigue determination unit 40 and measurement is performed, and a measurement non-execution state in which the measurement signal S01 is not taken into the fatigue determination unit 40 and measurement is not performed, based on the state of the measurement control signal S02 transmitted from the input unit 23. For example, the measurement switching unit 31 is in the measurement execution state when the measurement control signal S02 is transmitted from the switch 22 to the input unit 23, and in the measurement non-execution state when the measurement control signal S02 is not transmitted from the switch 22 to the input unit 23. Therefore, the user confirms that the probe 21 is in the correct orientation and contacts the raceway surface 61 of the bearing outer ring 60 shown in Figure 2, and then presses the switch 22 to transition the reuse decision support device 10 to the measurement execution state. In the measurement execution state, the data holding unit 32 holds the measurement signal S01 obtained by eddy current measurement on the raceway surface 61 of the outer ring 60.

[0018] The fatigue determination unit 40 performs a reuse determination based on the output voltage value obtained by eddy current measurement of the bearing to be measured, i.e., the measured value. The measured value is the output voltage value (X voltage, Y voltage) of the X and Y axes on the X-Y coordinate plane represented by the X and Y axes. The fatigue determination unit 40 includes a map storage unit 41, a bearing information processing unit 42, a measurement mode switching unit 43, an output voltage value calculation unit 44, and a reuse determination result display unit 46.

[0019] The fatigue determination unit 40 may include, for example, a computer including a processor and peripheral components such as a memory device. The processor may be, for example, a CPU (Central Processing Unit) or an MPU (Micro-Processing Unit). The memory device may include any of semiconductor memory devices, magnetic memory devices, and optical memory devices. The memory device may include registers, cache memory, and memory such as ROM (Read Only Memory) and RAM (Random Access Memory) used as main memory. The fatigue determination unit 40 may be configured with dedicated hardware for executing each information processing. For example, the fatigue determination unit 40 may include functional logic circuits set in a general-purpose semiconductor integrated circuit. For example, the fatigue determination unit 40 may have a programmable logic device (PLD) such as a field-programmable gate array (FPGA).

[0020] The memory device inside the fatigue determination unit 40 may store a program for implementing the reuse decision support method and fatigue layer removal method described later. The processor of the fatigue determination unit 40 may read the program stored in the memory device and execute the method related to the program.

[0021] The map storage unit 41 stores a determination map (see Figure 4) in which the output voltage values ​​(X voltage, Y voltage) obtained by eddy current measurement of the bearing are represented on the X-Y coordinate axis, and the fatigue level at each coordinate is associated with that determination map. The bearing information processing unit 42 obtains basic information about the bearing by referring to the data storage unit 50, which will be described later, in particular the basic information DB (database) 51. The measurement mode switching unit 43 determines whether or not the basic information includes output voltage value data for a new bearing. Details of the bearing information processing unit 42 and the measurement mode switching unit 43 will be described in Modification Example 1 below (Figure 6).

[0022] The output voltage value calculation unit 44 calculates the output voltage value (X voltage, Y voltage) obtained by eddy current measurement of the bearing to be measured, based on the held measurement signal S01. The reuse determination result display unit 46 includes a determination unit 46a that determines whether the bearing to be measured is usable, requires repair, or is unusable, based on the output voltage value calculated by the output voltage value calculation unit 44 and a determination map, and a presentation unit 46b that presents and displays the reuse determination result. The reuse determination result (determination result) indicates whether the bearing is usable, requires repair, or is unusable.

[0023] The data storage unit 50 is a storage unit that stores data necessary for the determination. The data storage unit 50 includes a basic information DB 51 that stores basic information, particularly about bearings, such as the bearing name and type of the bearing to be determined, the name of the equipment to be determined, whether or not there is new bearing data, correction value information described later, and past repair history. The data storage unit 50 may be configured as a dedicated server, dedicated cloud, etc., dedicated to bearing life determination.

[0024] Figure 2 is a schematic diagram showing the state of measuring eddy currents on the raceway surface 61 of the outer ring 60 of a rolling bearing using a probe 21. As shown in Figure 2, the probe 21 contacts the raceway surface 61 and applies an alternating magnetic field to induce eddy currents on the raceway surface 61, thereby measuring the eddy currents on the raceway surface 61. The measurement signal S01, which represents the output voltage value obtained by this eddy current measurement, is transmitted to the input unit 23 via the cable 24. When the surface to be measured is the raceway surface 61 of the outer ring 60, the determination unit 46a uses a determination map that is pre-stored in the map storage unit 41 of the fatigue determination unit 40, which includes the relationship between the X voltage and Y voltage, which are the output voltage values ​​of the raceway surface 61 of the outer ring 60, and the fatigue level of the outer ring 60. Therefore, based on this determination map and the output voltage value obtained by measuring the eddy currents on the raceway surface 61 of the outer ring 60, a reuse determination result for the outer ring 60 is obtained.

[0025] The output voltage value calculation unit 44 calculates the output voltage values ​​(X voltage, Y voltage) of the raceway surface 61 of the outer ring 60 based on the measurement signal S01 held in the data holding unit 32. The output voltage value calculation unit 44 acquires the output voltage values ​​included in the measurement signal S01 and provides them to the determination unit 46a. Alternatively, as will be described later, the output voltage value calculation unit 44 may calculate output voltage values ​​that take into account the output voltage values ​​(initial values) of the raceway surface 61 of the outer ring 60 in a new state and provide them to the determination unit 46a.

[0026] The determination unit 46a determines whether the outer ring 60 is reusable based on the X and Y components (X voltage, Y voltage) of the output voltage value obtained by eddy current measurement on the raceway surface 61 of the outer ring 60, which are calculated by the output voltage value calculation unit 44, and the determination map stored in the map storage unit 41. The result of the outer ring 60 reuse determination is displayed on the display unit 46b.

[0027] FIG. 3 is a flowchart showing the procedure of the resource determination support method performed by the resource determination support apparatus 10 according to Embodiment 1. This procedure is particularly executed by the determination result display unit 46 for resource determination. That is, the determination unit 46a of the determination result display unit 46 for resource determination determines whether the bearing corresponds to any of continuous usability, requiring repair, or unusable based on a determination map (stored in the map storage unit 41) including the relationship between the output voltage value shown in FIG. 4 and the fatigue degree of the bearing, and the output voltage values (X voltage, Y voltage) calculated by the output voltage value calculation unit 44. The presentation unit 46b of the determination result display unit 46 for resource determination presents (displays) the determination result by the determination unit 46a.

[0028] When the output voltage value calculated by the output voltage value calculation unit 44 is in the area where the fatigue degree is 50% or less in the determination map (the first area in FIG. 4) (Yes in step S1), the resource determination result display unit 46 proceeds to the process of step S2. In step S2, the determination unit 46a determines that the bearing is continuously usable, and the presentation unit 46b displays that it is continuously usable. The determination unit 46a transmits determination information indicating that the determination target bearing is continuously usable to the data storage unit 50, and the basic information DB51 updates the information of the bearing (step S3).

[0029] When the output voltage value calculated by the output voltage value calculation unit 44 is not in the area where the fatigue degree is 50% or less in the determination map (No in step S1), and is in the area where the fatigue degree exceeds 50% and is 80% or less in the determination map (the second area in FIG. 4) (Yes in step S4), the resource determination result display unit 46 proceeds to the process of step S5. In step S5, the determination unit 46a determines that the bearing requires repair, and the presentation unit 46b displays that it requires repair. The determination unit 46a transmits determination information indicating that the determination target bearing requires repair to the data storage unit 50, and the basic information DB51 updates the information of the bearing (step S6).

[0030] If the output voltage value calculated by the output voltage value calculation unit 44 is not in an area of ​​the judgment map where the fatigue level exceeds 50% and is 80% or less (No in step S4), that is, if the output voltage value is in an area where the fatigue level exceeds 80% (the third area in Figure 4), the reuse judgment result display unit 46 proceeds to the process in step S7. In step S7, the judgment unit 46a determines that the bearing to be judged is unusable (requires replacement), and the display unit 46b displays that it is unusable. The judgment unit 46a transmits the judgment information that the bearing to be judged is unusable to the data storage unit 50, and the basic information DB 51 updates the information of the bearing (step S8).

[0031] Figure 4 shows the judgment map stored in the map storage unit 41. This judgment map represents the output voltage values ​​obtained by eddy current measurement of the bearing on the X-Y coordinate axis, and is a judgment map in which the fatigue degree at each coordinate is associated. The judgment map is created based on a technology established by the inventors that can predict the fatigue degree of a bearing using the results of eddy current measurement of the bearing. Due to fatigue, bearings undergo a decrease in retained austenite, a decrease in dislocation density, and changes in surface properties. Due to these changes, the output voltage values ​​detected by eddy current measurement change, and although the behavior is complex, it has become clear that the result of representing the output voltage values ​​on the X-Y coordinate axis (plot of measured values) moves regularly on the X-Y coordinate, and the fatigue degree of the bearing can be predicted from the values ​​(points) on the X-Y coordinate. Furthermore, the inventors have constructed a database of the relationship between fatigue degree and the X-Y coordinate, and have succeeded in constructing a judgment map that predicts the fatigue degree from the X and Y coordinate values ​​obtained by eddy current measurement. Specifically, the judgment map is created using a test bearing with the same specifications as the rolling bearing that is actually used. Specifically, in creating the judgment map, an excitation current is passed through the coil in the probe 21 to induce eddy currents on the surface of the test bearing to be measured, and the voltage value (output voltage value) generated in the coil by these eddy currents is recorded. At the same time, the amount of retained austenite and the full width at half maximum of the martensite are measured using an X-ray measuring device.

[0032] The fatigue degree measured using the X-ray measuring device was calculated by the following formula (1) by measuring the decrease amount δa of the martensite half-width and the decrease amount δb of the retained austenite with respect to the initial product using X-rays. Here, the fatigue degree (%) is (operation time at the time of measurement / separation time) × 100. C is an arbitrary constant. Fatigue degree (%) = 50 × (δa + C × δb) ··· (1)

[0033] In this way, for a predetermined location (for example, 4 locations) of the outer ring of a predetermined number (for example, 6) of test bearings at each elapsed time, the fatigue degree calculated from the values measured by the X-ray measuring device is associated with the output voltage value obtained by eddy current measurement using the probe 21, thereby providing a determination map as shown in FIG. 4.

[0034] The determination map is a map in which the output voltage value obtained by eddy current measurement as described above is represented on the X-Y coordinate axes, and a threshold value that serves as a criterion for determination by the determination unit 46a is set in consideration of the correlation between the fatigue degree and the output voltage value. The correlation between the fatigue degree and the output voltage value will be described later. In the determination map shown in FIG. 4 in which the impedance is represented by the output voltage values (X voltage, Y voltage), as shown in the figure, it is divided into the first region, the second region, and the third region according to two threshold values. The first region is an area where the fatigue degree is 50% or less, the second region is an area where the fatigue degree exceeds 50% and is 80% or less, and the third region is an area where the fatigue degree exceeds 80%. According to this determination map, when the measured value of the output voltage value is plotted in the first region, that is, when the fatigue degree is 50% or less, the determination unit 46a determines that continuous use is possible. Also, when the measured value of the output voltage value is plotted in the second region, that is, when the fatigue degree exceeds 50% and is 80% or less, the determination unit 46a determines that repair is required. Further, when the measured value of the output voltage value is plotted in the third region, that is, when the fatigue degree exceeds 80%, the determination unit 46a determines that it is unusable. Hereinafter, the basis for this determination criterion (threshold value) will be explained.

[0035] The following has been found regarding the correlation between fatigue level and output voltage value, that is, the correlation between fatigue level obtained by an X-ray measuring device and plots obtained by eddy current measurement (ECT plots) (see Japanese Patent Publication No. 5751166): When material fatigue occurs in the object being measured (bearing), the plot of output voltage value (measured value) on the X-Y coordinate plane shifts in a specific direction. When the surface properties of the object being measured change, the plot of the measured value shifts in yet another specific direction.

[0036] Based on the above, the inventors have conducted diligent research and obtained the following findings: ・When the fatigue level is 50% or less, the fatigue of the material structure and the change in surface properties are very small. Therefore, under the same operating conditions, the bearing can be reused for the same period as before (continued use is possible). ・When the fatigue level is between 50% and 80%, the fatigue of the material structure is predominant, so the fatigue can be recovered by removing the fatigue layer. Therefore, the bearing can be reused (repair required) after the fatigue layer is removed. ・When the fatigue level exceeds 80%, changes in surface properties due to delamination or significant wear become dominant. In this case, the bearing is difficult to reuse, and replacement is recommended (unusable). Based on the above findings, the determination unit 46a determines whether the bearing is usable for continued use, requires repair, or is unusable, according to the fatigue level.

[0037] Note that the judgment map shown in Figure 4 will vary depending on the size and type of bearing, the operating lubrication conditions, the measurement conditions, etc., resulting in different numerical values ​​and ranges indicating the same fatigue level. For this reason, the map storage unit 41 has multiple judgment maps prepared for each bearing specification, corresponding to the inner ring, outer ring, and rolling elements.

[0038] Figure 5 shows an example of the operation image of the reuse decision support system 1 according to this embodiment. During periodic maintenance of bearings, bearings are removed from the end user's equipment and brought to the inspection area (for example, the inspection facility of the inspection company that makes the judgment). In the inspection area, an inspector visually inspects the appearance of the bearings (step S11), and bearings that are judged as NG by visual inspection are to be discarded (step S12). Bearings that are judged by the inspector by visual inspection to require repair are repaired at a repair factory (step S13).

[0039] On the other hand, bearings that are deemed OK by visual inspection by an inspector become subject to reuse decision support (fatigue diagnosis) by the reuse decision support system 1 (step S14). If the reuse decision support system 1 determines that the bearing can be used again (step S15), the end user continues to operate the equipment using the bearing (step S16). If the reuse decision support system 1 determines that the bearing requires repair (step S17), it becomes subject to repair at a repair factory (step S13). If the reuse decision support system 1 determines that the bearing is unusable (step S18), it becomes subject to disposal (step S12).

[0040] According to this embodiment, based on the fatigue level of the bearing according to the measurement signal S01, it is indicated whether the bearing is usable for continued use, requires repair, or is unusable. Therefore, the user can take subsequent actions such as continued use, repair, or replacement based on quantitative diagnosis without having to decide whether or not to reuse the bearing themselves. In this way, by quantitatively determining whether to continue using, repair, or discard the bearing from the perspective of material fatigue, it is possible to reduce the burden on the user, prevent sudden equipment shutdowns, and contribute to improving the production efficiency of the equipment.

[0041] (Embodiment 2) Figure 6 is a flowchart showing the procedure of the reuse decision support method performed by the reuse decision support device 10 according to Embodiment 2. In this embodiment, the measurement mode switching unit 43 of the fatigue determination unit 40 switches the measurement mode by referring to the basic information of the bearing to be judged. The configuration of the reuse decision support system 1 and the reuse decision support device 10 in this embodiment is the same as in Embodiment 1.

[0042] First, the bearing information processing unit 42 of the fatigue determination unit 40 refers to the data storage unit 50, in particular the basic information DB 51, to acquire basic information about the bearing (step S21). Then, the measurement mode switching unit 43 determines whether or not the basic information includes output voltage value data for a new bearing (step S22). A new bearing means a state in which the bearing is not fatigued, the state of the bearing before use, etc., and the output voltage value data for a new bearing becomes the so-called initial value.

[0043] If the basic information includes output voltage value data for a new bearing (Yes in step S22), the measurement mode switching unit 43 switches the operation mode of the reuse judgment support device 10 to the first mode (step S23) and proceeds to the judgment by the fatigue judgment unit 40 (step S24). The first mode is a mode that measures only the load measurement position on the raceway surface of the bearing that receives the load. The load measurement position is the measurement position by the probe 21, that is, the position where the probe 21 is in contact with the surface to be measured.

[0044] In the first mode, by measuring only the load area, work efficiency can be improved in the case of static load wheels where the load area is limited to a specific location. For example, to identify the load area, it is desirable to visually check the running marks formed on the running surface of the raceway after bearing disassembly and define the area in which running marks are formed in the circumferential direction as the load area. Alternatively, it is desirable to define the fretting area formed on the inner or outer diameter surface as the load area.

[0045] The output voltage value calculation unit 44 employs either equation (2) or equation (3) described below when calculating the output voltage value in the first mode.

[0046] On the other hand, if the basic information does not include output voltage value data for a new condition (No in step S22), the measurement mode switching unit 43 switches the operation mode of the reuse judgment support device 10 to the second mode (step S25) and proceeds to the judgment by the fatigue judgment unit 40 (step S24). The second mode is a mode in which, in addition to the load measurement position on the raceway surface of the bearing that receives a load, a position on the raceway surface that does not receive a load or a position on a different surface from the raceway surface that does not receive a load is used as a reference position for measurement. The output voltage value calculation unit 44 uses the formula (4) described below to calculate the output voltage value in the second mode.

[0047] According to this embodiment, the operating mode can be switched between cases where the basic information includes the output voltage value of a new bearing and cases where it does not, allowing for a determination appropriate to the situation. Specifically, when the basic information includes the output voltage value of a new bearing, the so-called initial value, a determination can be made appropriately using the first mode, which utilizes the initial value. Furthermore, when the basic information does not include this initial value, a determination can be made appropriately using the second mode, which uses an unloaded position on the raceway surface or an unloaded position on a different surface from the raceway surface as the reference position.

[0048] Furthermore, the output voltage value calculation unit 44 can calculate the difference between the output voltage value based on the measurement signal in the first mode and the output voltage value data for a new product as the load region output voltage value in the region on the bearing raceway surface that receives a load.

[0049] The method for calculating the output voltage value in the load region can be appropriately selected depending on the material constituting the bearing. For example, in the first mode, if the bearing is made of bearing steel, considering the characteristic of bearing steel that material structure variation is small, the output voltage value in the load region can be determined by the following formula (2): Output voltage value in the load region = Raceway surface measurement value (output voltage value) of a used bearing (fatigued product) - Average of raceway surface measurement values ​​(output voltage value data) of a new bearing ... (2)

[0050] Furthermore, in the first mode, when the bearing is made of carburized steel, considering the characteristic of carburized steel that there is a large variation in material structure depending on the location due to the hardening condition, the output voltage value in the load region is determined by the following formula (3): Output voltage value in the load region = Raceway surface measurement value (output voltage value) of a used bearing (fatigued product) at the same location as a new bearing - Raceway surface measurement value (output voltage value data) of a new bearing ... (3)

[0051] On the other hand, the output voltage value calculation unit 44 can calculate the load region output voltage value by adding a correction value to the difference between the output voltage value based on the measurement signal at the load measurement position and the output voltage value based on the measurement signal at the reference position among the measurement signals in the second mode. In this case, the load region output voltage value is obtained by the following formula (4): Load region output voltage value = (Measurement value of the raceway surface of the load region of the bearing (fatigued product) after use (output voltage value) - Average of measurement values ​​at the reference position (output voltage value)) - Correction value ... (4)

[0052] Figure 7 is an illustrative diagram of the process for determining the correction value in equation (4) in the second mode described above, where (A) is an illustrative diagram of the outer ring of the bearing and (B) is an illustrative diagram of the inner ring of the bearing. In Figure 7, an example is assumed in which the outer ring is fixed and the inner ring rotates. As shown in Figure 7(A), the outer ring, which is subjected to a static load, has a load region (load zone) in a specific area, and as shown in Figure 7(B), the inner ring, which is subjected to a rotational load, has a load region around its entire circumference. In equation (4), the part (measured value of the raceway surface in the load region of the bearing after use (fatigued product) - average of the measured value at the reference position) is measured at the actual measurement site. On the other hand, the correction value in equation (4) is determined in advance by measuring new bearings of various specifications (types, sizes) and determining the relationship between them. Specifically, the correction value is determined by subtracting the measured value at the same phase as the measurement position on the inner and outer diameter raceway surfaces from the average value (average measured value) of each measured value at multiple phases in which the raceway surface is equally distributed at at least two locations in the circumferential direction.

[0053] Figure 8 is a graph illustrating the calculation of correction values ​​according to the raceway diameter. The correction values ​​are calculated as follows. First, as shown in Figure 8, the results of measuring "average measured value of the raceway surface of a new bearing - average measured value in the load area of ​​the inner or outer diameter surface" are plotted for bearings of various specifications. All measured values ​​are output voltage values ​​obtained by eddy current measurement. Next, a relationship equation between the plotted measured values ​​(correction values) and the raceway diameter is determined. In Figure 8, two types of relationship equations (correction equation A and correction equation B) are determined with the raceway diameter Ad as the boundary. Then, depending on the raceway diameter of the bearing being measured, correction equation A is used for raceway diameters smaller than a predetermined raceway diameter Ad, and correction equation B is used for raceway diameters equal to or greater than or equal to raceway diameter Ad to determine the correction value.

[0054] This allows the calculation method for the load region output voltage value to be switched depending on whether the basic information includes output voltage value data for a new bearing or not, enabling appropriate judgments for the situation.

[0055] (Embodiment 3) Figures 9 and 10 are illustrative diagrams of the reuse decision support method performed by the reuse decision support device 10 according to Embodiment 3. Figure 9 is an explanatory diagram for the case of a bearing made of bearing steel, and Figure 10 is an explanatory diagram for the case of a bearing made of carburized steel. This embodiment is based on the premise that the basic information DB51 includes output voltage value data of the bearing in a new state, and is a special example of the first mode of Embodiment 2 described above. Figures 9 and 10 show an example in which the outer ring is fixed and the inner ring rotates.

[0056] Figure 9(A) is an image of the outer ring of a bearing made of bearing steel, and Figure 9(B) is an image of the inner ring of a bearing made of bearing steel. When a bearing is made of bearing steel, the variation in material structure is small. Therefore, in the first mode, the load measurement position, i.e., the measurement position by the probe 21, is set to the axial position (position of the maximum measurement value) with the largest output voltage value on the same phase at at least one phase in the circumferential direction of the rolling surface of the load region, in the case of a raceway ring with a load region, as shown in the outer ring of Figure 9(A). The maximum measurement value is the measurement value (output voltage values ​​of the X and Y axes) where the plots showing the output voltage values ​​of the X and Y axes on the X-Y coordinate plane obtained at each measurement position are located furthest towards the third region. On the other hand, in the case of a raceway ring subjected to rotational load, as shown in the inner ring of Figure 9(B), the load measurement position is set to the axial position with the largest output voltage value on the same phase at at least two or more phases (four in Figure 9(B)) where the rolling surface is equally distributed in the circumferential direction. In Figure 9(A), it is generally the case that fatigue progresses most rapidly and the output voltage is highest at the center of the load region in the circumferential direction. Therefore, it is preferable to measure at the center of the load region in the circumferential direction, as indicated by arrow X.

[0057] This allows for the setting of appropriate load measurement positions according to the characteristics of bearing steel, which have low material structure variation, and enables accurate determination, taking into account the characteristics of the load on the raceway. Specifically, for raceway wheels with a load region, the position with the largest output voltage value in the circumferential direction of the rolling surface of the load region can be measured. On the other hand, for raceway wheels subjected to rotational loads, the position with the largest output voltage value can be measured at multiple phases in the circumferential direction.

[0058] Figure 10(A) is an image of the outer ring of a bearing made of carburized steel, and Figure 10(B) is an image of the inner ring of a bearing made of carburized steel. When a bearing is made of carburized steel, there is a large variation in the material structure depending on the hardening condition, etc. Therefore, in the first mode, the load measurement position, i.e., the measurement position by the probe 21, is set to the same position as the measurement position of the output voltage value data in a new state (new measurement position) at at least one phase in the circumferential direction of the rolling surface of the load region in the case of a raceway ring with a load region, as shown in Figure 10(A). On the other hand, in the case of a raceway ring that receives a rotational load, as shown in Figure 10(B), the measurement position is set to the same position as the measurement position of the output voltage value data in a new state at at least two or more phases (four locations in Figure 10(B)) that are equally distributed in the circumferential direction of the rolling surface. In Figure 10(A), the center of the load region indicated by position P1 is most likely to be the area where fatigue has progressed the most along the circumference. However, since there is no initial value corresponding to position P1, it is possible to take measurements at a position within the load region where measurements were taken in a new condition, as indicated by the arrow Y.

[0059] This allows for the setting of appropriate load measurement positions according to the characteristics of carburized steel, which exhibits large variations in material structure, and enables accurate determination. Specifically, for raceways with a load region, the same position as the measurement position for output voltage data in a new state can be measured in the circumferential direction of the rolling surface of the load region. On the other hand, for raceways subjected to rotational loads, the same position as the measurement position for output voltage data in a new state can be measured at multiple phases in the circumferential direction.

[0060] (Embodiment 4) Figure 11 is an image diagram of the process of the reuse decision support method performed by the reuse decision support device 10 according to Embodiment 4. As a premise, the bearing has a two-dimensional code or data matrix that includes output voltage value data of a new state measured by the probe 21 at the time of factory shipment. In addition, the reuse decision support device 10 according to this embodiment is equipped with a reading terminal 65 as a reading unit that can read this two-dimensional code or data matrix and acquire output voltage value data of a new state, in addition to the configuration of the first embodiment. In Figure 11, an information terminal as a user-operable interface is connected to the reuse decision support device 10, and the reuse decision support device 10 reads the two-dimensional code or data matrix and acquires output voltage value data of a new state via the reading terminal 65 and the information terminal.

[0061] The output voltage value calculation unit 44 calculates the output voltage value after the bearing has been used, and can also calculate the difference in output voltage values ​​before and after bearing fatigue using the output voltage value data of the new state contained in the two-dimensional code or data matrix read by the reading terminal 65.

[0062] This makes it easy to read the output voltage value data for the initial, new state, and reduces the complexity of setting up the measurement to match the initial value. The two-dimensional code or data matrix may include data such as bearing name, bearing product number, measurement position, output voltage value (X value, Y value), measurement conditions (frequency, phase, gain, filter information), S / N ratio of the probe used, and S / N ratio of the calibration master used.

[0063] (Embodiment 5) Figure 12 is an image diagram of the process of the reuse decision support method performed by the reuse decision support device 10 according to Embodiment 5. As a premise, the bearing has a data storage unit 50 in which output voltage value data in a new state is stored, or a two-dimensional code or data matrix that includes access information to a dedicated server or dedicated cloud equivalent to the data storage unit 50, at the time of factory shipment. Furthermore, in addition to the configuration of the first embodiment, the reuse decision support device 10 according to this embodiment is equipped with a reading terminal 65 as a reading unit that can read this two-dimensional code or data matrix and access the data storage unit 50, etc., to acquire output voltage value data in a new state. In Figure 12, an information terminal as a user-operable interface is connected to the reuse decision support device 10, and the reuse decision support device 10 reads the two-dimensional code or data matrix via the reading terminal 65 and the information terminal, accesses the data storage unit 50, etc., and acquires output voltage value data in a new state.

[0064] The output voltage value calculation unit 44 calculates the output voltage value after the bearing has been used, and can also calculate the difference between the output voltage value of the bearing before and after fatigue using the output voltage value data of the bearing in its new state stored in the data storage unit 50, or a dedicated server or dedicated cloud equivalent to the data storage unit 50.

[0065] This makes it easy to read the output voltage value data for the initial, new state, and reduces the complexity of setting the measurement parameters corresponding to the initial value. The data storage unit 50, or the dedicated server or dedicated cloud, may contain data similar to the two-dimensional code or data matrix of Embodiment 4.

[0066] (Embodiment 6) Figures 13 and 14 are conceptual diagrams of the reuse decision support method performed by the reuse decision support device 10 according to Embodiment 6, and all are conceptual diagrams of the outer ring. This embodiment is based on the premise that the basic information DB 51 does not include output voltage value data of the bearing in a new state, and is a special example of the second mode of Embodiment 2 described above. Figure 13 shows an example in which the outer ring is fixed and the inner ring rotates, and Figure 14 shows an example in which the outer ring rotates and the inner ring is fixed.

[0067] In the case of a raceway ring having a load region, as shown in Figure 13(A), there are cases where not only a rolling surface but also a non-rolling surface (a position on the raceway surface that is not under load) exists on the raceway surface. In such cases, by measuring with the non-rolling surface near the maximum measurement value of the fatigue surface as the reference position, the influence of variations in material structure (amount of retained austenite, full width at half maximum, etc., which is particularly noticeable in the case of carburized steel) can be suppressed. Therefore, the measurement position by the probe 21 is preferably any position on the same phase as the non-rolling surface at at least one phase in the circumferential direction of the load region, and it is preferable to take multiple measurements at that position and take the average value.

[0068] On the other hand, in the case of a raceway ring with a load region, as shown in Figure 13(B), there are cases where there is no non-running surface on the raceway surface, that is, the entire raceway surface is the running surface. In such cases, by measuring with a reference position that is on a surface different from the raceway surface (the outer diameter surface in the example of Figure 13(B)) and is not under load, the influence of surface properties (fretting, deformation, etc.) can be avoided. Therefore, the measurement position by the probe 21 is preferably any position on a surface different from the raceway surface and not under load at at least one phase in the circumferential direction, and it is preferable to take multiple measurements at that position and take the average value.

[0069] Furthermore, in the case of a raceway wheel subjected to rotational load, as shown in Figure 14(A), there are cases where not only a racing surface but also a non-racing surface (a position on the raceway surface that is not under load) exists on the raceway surface. In such cases, by measuring using the non-racing surface near the maximum measurement value of the fatigued racing surface as the reference position, the influence of variations in material structure (such as the amount of retained austenite and the full width at half maximum, which is particularly noticeable in the case of carburized steel) can be suppressed. Therefore, the measurement position by the probe 21 is preferably any position on the same phase of the non-racing surface in multiple phases distributed at least two (four in Figure 14(A)) in the circumferential direction, and it is preferable to take multiple measurements at that position and take the average value.

[0070] On the other hand, in the case of a raceway wheel subjected to rotational load, as in the outer ring of Figure 14(B), there are cases where there is no non-running surface on the raceway surface. In such cases, the influence of surface properties (fretting, deformation, etc.) can be avoided by measuring at a reference position on a surface different from the raceway surface (for example, the outer diameter surface or inner diameter surface) that is not under load. Therefore, the measurement position by the probe 21 is preferably an arbitrary position on a surface different from the raceway surface that is not under load, distributed at at least two (four in Figure 14(B)) in the circumferential direction, and it is preferable to take multiple measurements at that position and take the average value.

[0071] (Embodiment 7) In the measurement of output voltage values ​​described in Embodiments 1 to 6 above, there are cases in which the calculated output voltage value is clearly an abnormal value, i.e., an outlier.

[0072] Figure 15 is a conceptual diagram showing that the calculated output voltage value V, as displayed on the judgment map, is an outlier. For example, if multiple measurements and calculations are performed at a specific location on the bearing, values ​​exceeding 3σ, which are outside the range of the mean ±1 to 3σ (preferably 1.5σ) of the normal distribution, should be judged as outliers, and remeasurement is desirable. In Embodiment 7, the accuracy of the judgment is improved by prompting the user to remeasure when the reuse judgment support device 10 determines that an outlier exists.

[0073] Figure 16 is a flowchart showing the procedure for the reuse decision support method performed by the reuse decision support device 10 according to Embodiment 7. First, the output voltage value calculation unit 44 calculates the output voltage value based on the measurement of the probe 21 (step S31). The determination unit 46a of the reuse decision result display unit 46 starts determining whether the calculated value is an outlier (step S32). If the calculated value is not an outlier (No in step S33), the process ends. If the calculated value is an outlier (Yes in step S33), the display unit 46b of the reuse decision result display unit 46 displays a message recommending remeasurement (step S34).

[0074] The user, upon viewing the display on the display unit 46b, decides whether or not to perform a remeasurement (step S35). If the user decides not to perform a remeasurement (No in step S35), the process ends. If the user decides to perform a remeasurement (Yes in step S35), the reuse decision support device 10 is activated and the remeasurement is performed (step S36). After the remeasurement, the display unit 46b displays the remeasurement position where the remeasurement was performed (step S37). The determination unit 46a determines whether the remeasurement result is good or bad. If it is good (Yes in step S38), the outliers are updated with the remeasured values ​​(step S39). On the other hand, if the remeasurement result is not good (No in step S38), the process returns to step S34, and the display unit 46b displays a message recommending that the user perform a remeasurement.

[0075] Figure 17 is a conceptual diagram of a display by the display unit 46b recommending remeasurement. The display unit 46b, for example, indicates the position at a phase of 270° where an outlier value exists on the inner diameter surface of the inner ring, and displays a message such as "The measurement value at the inner diameter surface of the inner ring / phase 270° is abnormal. Please remeasure," recommending that the user remeasure.

[0076] (Embodiment 8) Figure 18 is a schematic diagram of the reuse decision support system 1 and reuse decision support device 10 according to Embodiment 8. In this embodiment, the reuse decision support system 1 further comprises a new product information DB 52 and a repair information DB 53 in the data storage unit 50 of the reuse decision support system 1 according to Embodiment 1 shown in Figure 1. In addition, the reuse decision result display unit 46 of the reuse decision support device 10 according to this embodiment comprises an information acquisition unit 46c that acquires new product information and repair information, which will be described later, from the new product information DB 52 and the repair information DB 53.

[0077] New product information DB52 includes new bearing price information, new bearing delivery time information, CO ２ New bearing information, such as emissions data, is received and stored from servers at product factories, etc. Repair information DB53 includes repair bearing price information, repair bearing delivery time information, CO ２ Estimated emissions information, CO2 ２The system receives and stores repair information related to bearing repair, such as actual discharge data, from servers at repair plants and other facilities. Since prices and delivery times for both new and repaired bearings fluctuate daily due to supply and demand from factories and transportation companies, it is desirable that this information be updated in real time on the servers at both the product factory and the repair plant.

[0078] After using machinery and equipment, if fatigued bearings are not to be used again, there are two options: replace them or repair (refurbish) them. In today's society, where concern for environmental issues is growing, which option is more CO2-efficient? ２ Whether it contributes to increasing the amount of reduction is an important factor. However, if the user is CO ２ Currently, it is difficult to quickly decide whether to replace or repair bearings while considering the amount of reduction. In this embodiment, the reuse decision support device 10 quickly presents options according to the situation by referring to the new product information DB 52 and the repair information DB 53.

[0079] Figure 19 is a flowchart showing the procedure of the reuse decision support method performed by the reuse decision support device 10 according to Embodiment 8. If the output voltage value calculated by the output voltage value calculation unit 44 is in the area of ​​the decision map where the fatigue level is 50% or less (the first area in Figure 4) (Yes in step S41), the reuse decision result display unit 46 proceeds to the process in step S42. In step S42, the decision unit 46a determines that the bearing can be used for continued use, and the information acquisition unit 46c of the reuse decision result display unit 46 acquires the CO2 value from the new product information DB 52. ２ The emission information is acquired. The display unit 46b indicates that it can be used continuously, and CO ２ The reduction amount information is displayed (step S43). The determination unit 46a transmits determination information to the data storage unit 50 indicating that the bearing to be determined can continue to be used, and the basic information DB 51 updates the information of the bearing (step S44).

[0080] When the output voltage value calculated by the output voltage value calculation unit 44 is not in the area with a fatigue degree of 50% or less in the determination map (No in step S41), and is in the area with a fatigue degree exceeding 50% and not exceeding 80% in the determination map (the second area in FIG. 4) (Yes in step S45), the reuse determination result display unit 46 proceeds to the process of step S46. In step S46, the determination unit 46a determines that the bearing requires repair, and the information acquisition unit 46c acquires the CO ２ emission amount information at the time of new product production from the new product information DB 52 and the CO ２ expected emission amount information at the time of repair from the repair information DB 53.

[0081] Furthermore, the information acquisition unit 46c acquires the CO ２ emission amount information at the time of new product production and the CO ２ difference between the expected emission amount information at the time of repair (CO ２ emission amount at the time of new product production - CO ２ expected emission amount), that is, calculates the CO ２ reduction amount information (step S47). Furthermore, the information acquisition unit 46c acquires the repair price information and the repair lead time information from the repair information DB 53 (step S48).

[0082] The presentation unit 46b displays the fact that repair is required, the CO ２ reduction amount information, the repair price information, and the repair lead time information (step S49). The determination unit 46a transmits the determination information indicating that the bearing to be determined requires repair to the data storage unit 50, and the basic information DB 51 updates the information of the bearing (step S50). Furthermore, the determination unit 46a transmits the actual emission amount information of the CO ２ required for repair to the data storage unit 50 after repair, and the repair information DB 53 updates the original CO ２ expected emission amount information to the received CO ２ actual emission amount information (step S51).

[0083] If the output voltage value calculated by the output voltage value calculation unit 44 is not in the area of ​​the determination map where the fatigue level exceeds 50% and is 80% or less (No in step S45), that is, if the output voltage value is in the area where the fatigue level exceeds 80% (the third area in Figure 4), the reuse determination result display unit 46 proceeds to the process in step S52. In step S52, the determination unit 46a determines that the bearing to be determined is unusable (requires replacement), and the information acquisition unit 46c acquires new product price information and new product delivery date information from the new product information DB 52. The display unit 46b displays that the bearing is unusable, along with the new product price information and new product delivery date information (step S53). The determination unit 46a transmits the determination information that the bearing to be determined is unusable to the data storage unit 50, and the basic information DB 51 updates the information of the bearing (step S54).

[0084] In this embodiment, the determination unit 46a obtains a determination result of whether the bearing is reusable or not, and the information acquisition unit 46c obtains the CO2 value of the bearing during continued use according to the determination result. ２ Reduction amount information and CO2 during bearing repair ２ The display unit 46b acquires information from at least one of the reduction amount information and displays the determination result and the information. This determines whether the bearing is reusable or not, along with the CO ２ By presenting reduction information, users can easily take subsequent actions, such as replacing or repairing and reusing bearings. ２ This can contribute to reducing emissions. Furthermore, when the information acquisition unit 46c acquires various types of information, it is desirable for the new product information DB 52 and the repair information DB 53 to query the servers of the product factory and repair factory for the latest information.

[0085] (Embodiment 9) Figure 20 is a flowchart showing the procedure of the reuse decision support method performed by the reuse decision support device 10 according to Embodiment 9. The configuration of the reuse decision support system 1 and the reuse decision support device 10 according to this embodiment is the same as in Embodiment 8.

[0086] After using machinery and equipment, if a fatigued bearing is not to be reused, there are options to either replace the fatigued bearing or repair it. However, it is currently difficult for users to quickly decide whether to replace or repair the bearing while considering the economic benefits. In this embodiment, the reuse decision support device 10 presents options according to the situation by referring to the new product information DB 52 and the repair information DB 53.

[0087] If the output voltage value calculated by the output voltage value calculation unit 44 is in the area of ​​the determination map where the fatigue level is 50% or less (the first area in Figure 4) (Yes in step S61), the reuse determination result display unit 46 proceeds to the process in step S62. In step S62, the determination unit 46a determines that the bearing can be used again, and the display unit 46b displays that it can be used again. The determination unit 46a transmits the determination information that the bearing to be judged can be used again to the data storage unit 50, and the basic information DB 51 updates the information of the bearing (step S63).

[0088] If the output voltage value calculated by the output voltage value calculation unit 44 is not in the area of ​​the determination map where the fatigue level is 50% or less (No in step S61), and is in the area of ​​the determination map where the fatigue level exceeds 50% but is 80% or less (the second area in Figure 4) (Yes in step S64), the reuse determination result display unit 46 proceeds to the process in step S65. In step S65, the determination unit 46a determines that the bearing requires repair, and the information acquisition unit 46c acquires new product price information and new product delivery date information from the new product information DB 52, and also acquires repair price information and repair delivery date information from the repair information DB 53.

[0089] The display unit 46b displays a message indicating that repair is required, along with information on the price of a new part, the delivery date for a new part, the repair price, and the delivery date for the repair (step S66). The determination unit 46a transmits the determination information that the bearing to be determined requires repair to the data storage unit 50, and the basic information DB 51 updates the information on the bearing (step S67).

[0090] If the output voltage value calculated by the output voltage value calculation unit 44 is not in the area of ​​the determination map where the fatigue level exceeds 50% and is 80% or less (No in step S64), that is, if the output voltage value is in the area where the fatigue level exceeds 80% (the third area in Figure 4), the reuse determination result display unit 46 proceeds to the process in step S68. In step S68, the determination unit 46a determines that the bearing to be determined is unusable (requires replacement), and the information acquisition unit 46c acquires new product price information and new product delivery date information from the new product information DB 52. The presentation unit 46b displays that the bearing is unusable, along with the new product price information and new product delivery date information (step S69). The determination unit 46a transmits the determination information that the bearing to be determined is unusable to the data storage unit 50, and the basic information DB 51 updates the information of the bearing (step S70).

[0091] In this embodiment, the determination unit 46a obtains a determination result of whether or not the bearing is reusable, the information acquisition unit 46c obtains at least one of the new bearing price information and the bearing repair price information according to the determination result, and the presentation unit 46b presents the determination result and the information. As a result, the new bearing price information or repair price information is presented along with the determination result of whether or not the bearing is reusable, so that the user can easily take the next action, such as replacing the bearing or repairing and reusing it. It also becomes easier to grasp the economic benefits. When the information acquisition unit 46c acquires various information, it is desirable that the new bearing information DB 52 and the repair information DB 53 query the servers of the product factory and the repair factory for the latest information.

[0092] (Embodiment 10) Figure 21 is a schematic diagram of the reuse decision support system 1 and reuse decision support device 10 according to Embodiment 10. In this embodiment, the reuse decision support system 1 further includes an insurance information DB 54 in the data storage unit 50 of the reuse decision support system 1 according to Embodiment 8 shown in Figure 18. The insurance information DB 54 receives and stores insurance information related to bearing insurance, such as contract information and guarantee amount information, from insurance companies, etc. The guarantee amount is determined according to the amount of insurance premiums paid to the insurance company based on an insurance contract concluded in advance with the insurance company regarding the bearings.

[0093] After using machinery and equipment, users have the option of replacing or repairing fatigued bearings. However, it is currently difficult for users to quickly decide whether to replace or repair bearings while considering whether insurance coverage applies. In this embodiment, the reuse decision support device 10 presents options according to the situation by referring to insurance information in the insurance information DB 54.

[0094] Figure 22 is a flowchart showing the procedure of the reuse decision support method performed by the reuse decision support device 10 according to Embodiment 10.

[0095] If the output voltage value calculated by the output voltage value calculation unit 44 is in the area of ​​the determination map where the fatigue level is 50% or less (the first area in Figure 4) (Yes in step S81), the determination unit 46a determines that the bearing can be used continuously, and the display unit 46b displays that it can be used continuously (step S82).

[0096] If the output voltage value calculated by the output voltage value calculation unit 44 is not in the area of ​​the determination map where the fatigue level is 50% or less (No in step S81), and is in the area of ​​the determination map where the fatigue level exceeds 50% but is 80% or less (the second area in Figure 4) (Yes in step S83), the reuse determination result display unit 46 proceeds to the process in step S84. In step S84, the determination unit 46a determines that the bearing requires repair, and further determines whether the repair is covered by insurance. The determination unit 46a determines whether the repair is covered by insurance based on the warranty period, the cause of the damage, the extent of the damage, etc.

[0097] If the repair is covered by insurance (Yes in step S84), the information acquisition unit 46c acquires the guaranteed amount information from the insurance information DB 54, the new product price information and new product delivery date information from the new product information DB 52, and the repair price information and repair delivery date information from the repair information DB 53 (step S85).

[0098] Next, the determination unit 46a calculates the repair cost, and also calculates the new product price after warranty application and the repair price after warranty application (step S86). The new product price after warranty application is the amount obtained by subtracting the warranty amount from the original new product price obtained from the new product information DB 52 (new product price after warranty application = original new product price - warranty amount). The repair price after warranty application is the amount obtained by subtracting the warranty amount from the original repair price obtained from the repair information DB 53 (repair price after warranty application = original repair price - warranty amount).

[0099] The display unit 46b displays that repair is required, along with information on the price of a new product after warranty application, information on the delivery date of a new product, information on the repair price after insurance application, and information on the repair delivery date (step S87). The determination unit 46a transmits the determination information that the bearing to be determined requires repair to the data storage unit 50, and the basic information DB 51 updates the information of the bearing (step S88).

[0100] On the other hand, if the repair is not covered by insurance in step S84 (No in step S84), the information acquisition unit 46c acquires new product price information and new product delivery date information from the new product information DB 52, and also acquires repair price information and repair delivery date information from the repair information DB 53 (step S89).

[0101] The display unit 46b displays that the bearing requires repair, along with information on the price of a new part, the delivery date for a new part, the repair price, and the delivery date for the repair (step S90). The determination unit 46a transmits the determination information that the bearing to be determined requires repair to the data storage unit 50, and the basic information DB 51 updates the information on the bearing (step S91).

[0102] Furthermore, if the output voltage value calculated by the output voltage value calculation unit 44 in step S83 is not in the area of ​​the determination map where the fatigue level exceeds 50% and is 80% or less (No in step S83), that is, if the output voltage value is in the area where the fatigue level exceeds 80% (the third area in Figure 4), the reuse determination result display unit 46 proceeds to the process in step S92. In step S92, the determination unit 46a determines that the bearing is unusable (requires replacement), and further determines whether the replacement (purchase of a new one) is covered by insurance. The determination unit 46a determines whether the replacement is covered by insurance based on the warranty period, cause of damage, extent of damage, etc.

[0103] If the replacement is covered by insurance (Yes in step S92), the information acquisition unit 46c acquires the guaranteed amount information from the insurance information DB 54 and acquires the new product price information and new product delivery date information from the new product information DB 52 (step S93).

[0104] Next, the determination unit 46a calculates the new product price information after the warranty has been applied (step S94). The new product price after the warranty has been applied is the original new product price obtained from the new product information DB 52 minus the warranty amount (new product price after warranty = original new product price - warranty amount).

[0105] The display unit 46b displays that the bearing is unusable (requires replacement), along with information on the price of a new bearing after warranty application and information on the delivery date of a new bearing (step S95). The determination unit 46a transmits determination information that the bearing to be determined is unusable to the data storage unit 50, and the basic information DB 51 updates the information on the bearing (step S96).

[0106] On the other hand, if the replacement in step S92 is not covered by insurance (No in step S92), the information acquisition unit 46c acquires new product price information and new product delivery date information from the new product information DB 52 (step S97).

[0107] The display unit 46b displays that the bearing is unusable, along with new product price information and new product delivery date information (step S98). The determination unit 46a transmits determination information that the bearing to be determined is unusable to the data storage unit 50, and the basic information DB 51 updates the information of the bearing (step S99).

[0108] In this embodiment, the determination unit 46a obtains a determination result of whether the bearing is reusable or not, the information acquisition unit 46c obtains insurance amount information for the bearing according to the determination result, and the presentation unit 46b presents the determination result and either the new price information after warranty application or the repair price information after warranty application. As a result, the determination result of whether the bearing is reusable or not is presented along with the new price information after warranty application or the repair price information after warranty application, so that the user can easily take the next action, such as replacing the bearing or repairing and reusing it.

[0109] (Embodiment 11) Figure 23 is a schematic diagram of the reuse decision support system 1 and reuse decision support device 10 according to Embodiment 11. In this embodiment, the reuse decision support system 1 further includes an inventory information DB 55 in the data storage unit 50 of the reuse decision support system 1 according to Embodiment 8 shown in Figure 18. The inventory information DB 55 receives and stores inventory information related to bearing inventory, such as the number of bearings in stock, from retailers and the like. The reuse decision support device 10 also includes an order processing unit 70.

[0110] In this embodiment, when a bearing needs repair or replacement, the information acquisition unit 46c acquires information on the number of new bearings in stock from the inventory information DB 55, and the display unit 46b displays an order button for ordering a new bearing and an input screen for the order quantity. The display unit 46b may also display the bearing price and delivery date according to the order quantity.

[0111] When a user operates the order button displayed on the display unit 46b, the order processing unit 70 sends order information to the dealer. If the dealer has insufficient stock, the inventory information DB 55 may send an order instruction based on the order information to the new product information DB 52, and the new product information DB 52 may send a production instruction based on the order instruction to the product factory. In addition, if the dealer has insufficient stock, the order processing unit 70 may send a production instruction based on the order information to the product factory.

[0112] In this embodiment, the order processing unit 70 transmits order information to the retailer in response to user operations, or, if there is insufficient stock, an order instruction based on the order information is transmitted from the stock information DB 55 to the new product information DB 52, and a production instruction is transmitted from the new product information DB 52 to the product factory. Therefore, according to the reuse decision support system 1 of this embodiment, new bearings can be quickly prepared.

[0113] (Embodiment 12) When a bearing is used, a load is applied to the outer ring or inner ring via the rolling elements. This load causes fatigue to accumulate on the surface of the raceway of the outer ring or inner ring, inducing flaking. Depending on the type of bearing and the operating environment, the mechanism leading to flaking can be classified into internal near-point and surface-initiated, but in both cases, fatigue cracks are the initiation point of flaking. If this flaking phenomenon becomes severe, the bearing may require repair or become unusable.

[0114] From the perspective of global environmental issues and the efficient use of resources, technologies have been proposed to regenerate and reuse bearings instead of disposing of them as waste. In particular, it is preferable to consider reusing bearings that have been determined to require repair in the reuse determination described in the above embodiment.

[0115] While embodiments 1 to 11 described above focus on determining whether a bearing can be reused, this embodiment and subsequent embodiments describe a method for regenerating a bearing after its use. Bearing regeneration is performed by removing the fatigue layer that has formed on the surface of the outer ring or inner ring. In this embodiment, bearing regeneration is performed on the premise of a reuse determination made by the reuse determination support device 10 or reuse determination support system 1 described above.

[0116] The bearing regeneration method also utilizes the judgment map shown in Figure 4. If the output voltage value calculated by the output voltage value calculation unit 44 is in the area of ​​the judgment map where the fatigue level is 50% or less (the first area in Figure 4), the bearing is determined to be usable for continued use. On the other hand, if the output voltage value calculated by the output voltage value calculation unit 44 is in the area of ​​the judgment map where the fatigue level exceeds 80% (the third area in Figure 4), the bearing is determined to be unusable (requires replacement). In these cases, the bearing is not regenerated, and the bearing is either used for continued use or replaced.

[0117] On the other hand, if the output voltage value calculated by the output voltage value calculation unit 44 is in an area within the judgment map where the fatigue level exceeds 50% but is 80% or less (the second area in Figure 4), the bearing requires repair, and in this case, the bearing is refurbished.

[0118] Figure 24 is a flowchart showing the procedure for the bearing regeneration method performed by the reuse decision support device according to Embodiment 12. The reuse decision support device 10 used in this embodiment may be the same as that in Figure 1.

[0119] The output voltage value calculation unit 44 calculates the output voltage value (step S101). If the calculated output voltage value is not included in the second region of the determination map in Figure 4 (No in step S102), that is, if the calculated output voltage value is in the first or third region of the determination map in Figure 4, the reuse determination result display unit 46 proceeds to the process in step S103. In step S103, the determination unit 46a determines whether the bearing can be used for continued use or is unusable (requires replacement) and terminates the process.

[0120] On the other hand, if the output voltage value calculated by the output voltage value calculation unit 44 falls within the second region of the judgment map in Figure 4 (Yes in step S102), the user performs a process to remove the fatigue layer from the bearing's racing surface (step S104). The fatigue layer removal process can be performed using conventional cutting machines, grinding machines, etc. After processing, the reuse judgment support device 10 is used again to measure and calculate the output voltage value (step S105). If the output voltage value calculated again by the output voltage value calculation unit 44 falls within the first region of the judgment map in Figure 4 (Yes in step S106), that is, if the bearing can be used continuously, the removal of the fatigue layer is completed (step S107). If it does not fall within the first region of the judgment map in Figure 4 (No in step S106), the process returns to step S103, and the fatigue layer removal process is performed again.

[0121] This embodiment makes it possible to gradually and repeatedly remove the fatigue layer, thereby minimizing the amount of material removed and extending the lifespan of the bearing and making efficient use of resources.

[0122] Figure 25 is a flowchart showing the procedure for the regeneration method of a bearing made of bearing steel performed by the reuse decision support device 10 according to Embodiment 12, and is a flowchart showing the procedure for the regeneration of the inner ring, which is the raceway ring that receives the rotational load during inner ring rotation. Figure 26 is an image diagram of the process for the bearing regeneration method performed by the reuse decision support device 10 according to Embodiment 12, and is an image diagram of the inner ring of the bearing in the flowchart of Figure 25.

[0123] As shown in Figure 26, the output voltage value calculation unit 44 measures and calculates the output voltage value at each of the multiple phases, where the rolling surface is equally distributed at at least two locations in the circumferential direction, using the axial position with the largest output voltage value on the same phase as the load measurement position (step S111). Then, the position where the maximum value among the measured values ​​at the multiple load measurement positions is measured is defined as the machining measurement position (step S112).

[0124] The output voltage value calculation unit 44 calculates the output voltage value at the machining measurement position. If the calculation result at the machining measurement position is not included in the second region of the determination map in Figure 4 (No in step S113), that is, if the calculated output voltage value is in the first or third region of the determination map in Figure 4, the reuse determination result display unit 46 proceeds to the process in step S114. In step S114, the determination unit 46a determines whether the bearing can be used for continued use or is unusable (requires replacement).

[0125] On the other hand, if the output voltage value at the machining measurement position falls within the second region of the judgment map in Figure 4 (Yes in step S113), the user performs machining to remove the fatigue layer from the bearing's racing surface (step S115). After machining, a remeasurement is performed, and the output voltage value at the machining measurement position at that time is defined as the post-machining output voltage value (step S116). If the post-machining output voltage value falls within the first region of the judgment map in Figure 4 (Yes in step S117), the removal of the fatigue layer from the racing surface is completed (step S118). If the post-machining output voltage value does not fall within the first region of the judgment map in Figure 4 (No in step S117), the process returns to step S115, and the machining to remove the fatigue layer from the racing surface is performed again.

[0126] Figure 27 is a flowchart showing the procedure for the regeneration method of a bearing made of carburized steel performed by the reuse decision support device 10 according to Embodiment 12, and is a flowchart showing the procedure for the regeneration of the inner ring, which is a raceway ring that receives rotational load. Figure 28 is an image diagram of the process for the bearing regeneration method performed by the reuse decision support device 10 according to Embodiment 12, and is an image diagram of the inner ring of the bearing in the flowchart of Figure 27.

[0127] As shown in Figure 28, the output voltage value calculation unit 44 measures and calculates the output voltage value at multiple phases, where the turning surface is equally distributed at at least two locations in the circumferential direction, using the same position as the measurement position for the output voltage value data in the new state as the load measurement position (step S111A). The following steps are the same as in Figure 25.

[0128] Figure 29 is a flowchart showing the procedure for the regeneration method of a bearing made of bearing steel performed by the reuse decision support device 10 according to Embodiment 12, and is a flowchart showing the procedure for the regeneration of the outer ring, which is a raceway ring with a load area. Figure 30 is an image diagram of the process for the bearing regeneration method performed by the reuse decision support device 10 according to Embodiment 12, and is an image diagram of the outer ring of the bearing in the flowchart of Figure 29.

[0129] As shown in Figure 30, the output voltage value calculation unit 44 measures and calculates the output voltage value at each of the following points in the axial direction, where the measurement position with the largest output voltage value in the same phase is the load measurement position (step S111B). The following steps are the same as in Figure 25.

[0130] Figure 31 is a flowchart showing the procedure for the regeneration method of a bearing made of carburized steel performed by the reuse decision support device 10 according to Embodiment 12, and is a flowchart showing the procedure for the regeneration of the outer ring, which is a raceway ring with a load area. Figure 32 is an image diagram of the process for the bearing regeneration method performed by the reuse decision support device 10 according to Embodiment 12, and is an image diagram of the outer ring of the bearing in the flowchart of Figure 31.

[0131] As shown in Figure 32, the output voltage value calculation unit 44 measures and calculates the output voltage value at at least one phase in the circumferential direction of the rolling surface of the load area, using the same position as the measurement position for the output voltage value data in the new state as the load measurement position (step S111C). The following steps are the same as in Figure 25.

[0132] According to this embodiment, in the bearing regeneration method using the reuse judgment support device 10, the fatigue layer removal process and the remeasurement of the output voltage value after the removal process are repeated until the output voltage value after processing is included in the first region of the judgment map. Therefore, since the fatigue layer in which fatigue has accumulated can be removed while suppressing the amount of removal based on the change in the output voltage value, it is possible to provide a regenerated bearing that can maintain the original bearing performance.

[0133] (Embodiment 13) In the bearing regeneration process described in Embodiment 12, the fatigue layer is removed, which increases the clearance between the rolling elements and the outer or inner ring. Naturally, there is a limit to the allowable clearance, and the maximum allowable clearance standard is set for each bearing. The maximum clearance standard is specified, for example, in JIS B1520:2015 "Rolling bearings - Internal clearance - Part 1: Radial internal clearance of radial bearings". In this embodiment, by setting the limit removal amount so that the clearance after removal of the fatigue layer on the rolling surface does not exceed the maximum clearance standard of the bearing, the impact of changes in load conditions on bearing life can be suppressed.

[0134] Figure 33 is a schematic diagram showing the relationship between the maximum clearance specification, the clearance amount before removal processing, and the allowance for removal processing of the outer and inner rings combined. The clearance amount before removal processing is measured using a tool such as a feeler gauge. The value obtained by subtracting the clearance amount before removal processing from the maximum clearance specification is the allowance for removal processing of the outer and inner rings combined, i.e., the limit removal amount.

[0135] Figure 34 is a flowchart showing the procedure for calculating the limit removal amount based on the gap amount, which is performed by the reuse decision support device 10 according to Embodiment 13. The reuse decision support device 10 used in this embodiment may be the same as that in Figure 1.

[0136] The user obtains, for example, the maximum clearance specification of the bearing to be regenerated, which is stored in the data storage unit 50 (step S121). Before disassembling the machinery, the user measures the amount of clearance of the bearing using an instrument (step S122). The limit removal amount is calculated by subtracting the measured clearance value from the maximum clearance specification (step S123).

[0137] According to Embodiment 13, the limit removal amount can be calculated, thus preventing the clearance after removing the fatigue layer from exceeding the maximum clearance standard. However, depending on the condition of the bearing after use, even if the fatigue layer is removed by the limit removal amount, the fatigue level may not reach an acceptable level, such as an output voltage value of 50%, in which case the fatigue layer removal process is meaningless. Therefore, a removal necessity determination step may be added after the procedure shown in Figure 34 and before the fatigue layer removal step to determine whether or not fatigue layer removal is necessary. In the removal necessity determination step, for example, a pre-created map is used. In creating this map, first, several sample bearings with different fatigue levels are prepared, and the amount of removal required to reach an acceptable level for each fatigue level is measured and mapped. Then, in the removal necessity determination step, it is determined whether or not the relationship is satisfied, where the limit removal amount calculated in step S123 is greater than the amount of removal required to reach an acceptable level, as determined from the map. By performing the fatigue layer removal step on the condition that this relationship is satisfied, it is possible to prevent the bearing regenerated by the fatigue layer removal step from becoming defective (unusable).

[0138] (Embodiment 14) Although the limit removal amount can be calculated by Embodiment 13 described above, in the case of a single-row tapered roller bearing, it is difficult to directly calculate the limit removal amount because the clearance between the outer ring and the inner ring cannot be defined. However, the limit removal amount can be indirectly calculated from the value of the assembly width used when assembling the bearing.

[0139] Figure 35 shows a schematic diagram of a single-row tapered roller bearing, where Figure 35(A) is a cross-sectional view of the single-row tapered roller bearing, and Figure 35(B) is a schematic representation of the raceway surface of the single-row tapered roller bearing. As shown in Figure 35(A), the actual assembled width T in the axial direction of the bearing is equal to the minimum assembly width standard value T. ｍｉｎThis is the sum of the assembly width limit amount ΔT, and as shown in Figure 35(B), when the contact angle of the raceway surface is α, the assembly width limit amount ΔT and the limit removal amount A ｍａｘ The relationship is, A ｍａｘ = ΔT × sinα. The tolerances and permissible values ​​for metric series tapered roller bearings are specified in JIS B 1514-1:2017 Rolling bearings — Geometric specifications (GPS) and tolerances of products — Part 1: Radial bearings. The tolerances and permissible values ​​for inch series tapered roller bearings are specified in ANSI / ABMA std. 19 Tapered Roller Bearings — Radial Metric Design.

[0140] Figure 36 is a flowchart showing the procedure for calculating the limit removal amount performed by the reuse decision support device 10 according to Embodiment 14, when the bearing is a single-row tapered roller bearing, based on the assembly width value. The user, for example, stores in the data storage unit 50 the minimum assembly width standard value T of the bearing to be refurbished. ｍｉｎ Obtain the (step S131) ​​and measure the actual assembly width T before disassembling the bearing (step S132). From the actual assembly width T, the minimum standard assembly width T ｍｉｎ By subtracting this, the assembly width limit ΔT (= T - T) ｍｉｎ ) is calculated (step S133). After disassembling the bearing, the contact angle α of the raceway surface is measured (step S134), and the assembly width limit amount ΔT is set to limit removal amount A. ｍａｘ Convert to (=ΔT × sinα) (Step S135). Before performing the removal process, perform the removal necessity determination process described above to determine the limit removal amount A. ｍａｘ You can also determine whether the amount removed is greater than the amount required to reach the passing standard.

[0141] (Embodiment 15) When the bearing is made of carburized steel, it is desirable to determine the depth of the effective hardened layer and to determine the amount to be removed based on this depth in order to ensure the performance of the bearing. The effective hardened layer is a layer with a hardness of Hv (Vickers hardness) of 550 or more. The measurement of the depth from the surface to Hv 550 is specified in JIS G0557:2019 "Method for measuring the depth of the carburized hardened layer of steel".

[0142] Figure 37 is a graph showing an example of the relationship between surface depth and hardness gradient for a bearing made of carburized steel. As this graph shows, the hardness of carburized steel generally decreases as it approaches the effective hardened layer depth Yo (for example, the depth until Hv550). However, near the surface, in order to ensure hardness that can withstand the maximum shear stress, it is common to design the bearing so that the hardness gradient is gentler compared to the vicinity of the effective hardened layer depth Yo. Therefore, in Embodiment 15, the limit removal amount is set to a value less than or equal to the effective hardened layer depth Yo multiplied by a predetermined coefficient. This allows the performance of the bearing to be maintained. Furthermore, by setting the predetermined coefficient to 0.5 and setting the limit removal amount to 50% or less of the effective hardened layer depth Yo (Yo / 2 or less), the bearing can withstand the maximum shear stress at a hardness close to the surface hardness, thus maintaining the bearing performance. Before performing the removal process, the above-described removal necessity determination process may be performed to determine whether the limit removal amount is greater than the removal amount required to reach the acceptable line.

[0143] (Embodiment 16) Bearing regeneration can be performed not only once but multiple times, and the removal process is also performed multiple times. Therefore, saving past removal history and utilizing it for future regeneration is an important consideration. Figure 38 is a flowchart showing the procedure for calculating the limit removal amount, which is performed by the reuse decision support device 10 according to Embodiment 16, based on past removal history.

[0144] The determination unit 46a of the reuse determination result display unit 46 stores the limit removal amount of the bearing after the previous removal process in the data storage unit 50 (step S141). After the user removes the fatigue layer from the rolling surface (step S142), the determination unit 46a uploads the current removal amount to the data storage unit 50 (step S143). Then, the bearing information processing unit 42 obtains the limit removal amount after the previous removal process from the data storage unit 50, and the determination unit 46a calculates the next limit removal amount by subtracting the current total removal amount from the limit removal amount after the previous removal process (step S144). The determination unit 46a uploads the calculated next limit removal amount to the data storage unit 50 (step S145).

[0145] Figure 39 is a table showing the history image of the fatigue layer removal process stored in the data storage unit 50 according to the flowchart procedure in Figure 38. Various values ​​for the first, second, third, and current removal processes are stored as history. Note that the various values ​​shown in Figure 39 are for illustrative purposes only and are not experimental data. For the outer ring, Yo / 2, the limit removal amount, and the actual removal amount described in Embodiment 15 are stored. For the inner ring, the limit removal amount and the actual removal amount are stored. The total is the sum of the values ​​for the inner and outer rings. In addition, the determination of whether regeneration is possible or not for each process is also stored.

[0146] The initial total limit removal amount shown in Figure 39 is preferably determined based on a comparison of the limit removal amounts described in Embodiments 13 to 16. Specifically, if the bearing is made of carburized steel, the limit removal amount for each raceway is determined based on the effective hardened layer depth of each raceway described in Embodiment 15. In the case of a single-row tapered roller bearing, the total limit removal amount for the inner and outer rings is determined based on the minimum assembly width specification and the actual assembly width described in Embodiment 14. In the case of bearings other than single-row tapered roller bearings, the total limit removal amount for the inner and outer rings is determined based on the maximum clearance specification and the current clearance amount described in Embodiment 13. Of the limit removal amounts determined above, the amount showing the minimum value is determined as the initial total limit removal amount. This makes it possible to provide a reconditioned bearing that maintains its original bearing performance.

[0147] (Embodiment 17) The optimal amount of material to be removed for regeneration can also be determined by removing the fatigue layer from a bearing that has actually been used and obtaining fatigue parameters that indicate the surface condition. Fatigue parameters include, for example, the change in retained austenite, the change in half width, and evaluation values ​​with residual stress as parameters. Such fatigue parameters can be observed and obtained, for example, by X-ray diffraction. The inventors have found that, in a graph showing the relationship between the amount of surface (fatigue layer) removed from the bearing and the fatigue parameters, the value of the fatigue parameters decreases as the amount of material removed increases, but within the range from zero surface depth to the first inflection point, the value of the fatigue parameters decreases rapidly, and thereafter the value of the fatigue parameters decreases gradually. The determination of the optimal amount of material to be removed in this embodiment utilizes the characteristics of this graph.

[0148] First, a test bearing identical in specifications to the bearing to be refurbished is prepared. A fatigue test is performed on this test bearing to create a test piece with a surface fatigue level of 80% (the upper limit of the second region on the judgment map in Figure 4). In other words, in this embodiment, the amount to be removed is determined based on the bearing with the most severe fatigue level, which is 80%, among the bearings that are judged to require repair.

[0149] After removing the fatigue layer from the test piece, X-ray diffraction is performed to calculate the fatigue parameters. The removal of the fatigue layer and X-ray diffraction are repeated, and fatigue parameters corresponding to the surface depth are calculated. As a result, a graph of transition lines showing the relationship between the surface depth r and the fatigue parameter F is created. Figure 40 is a graph showing the transition line of the relationship between the surface depth r and the fatigue parameter F in surface fatigue, created in Embodiment 17.

[0150] By defining the amount of material removed corresponding to the point where the gradient transitioning from the surface first inflects among the created transition lines as the optimal removal amount, fatigue can be removed with the minimum number of processing steps.

[0151] (Embodiment 18) In Embodiment 17, among the bearings determined to require repair, a transition line is created based on the relationship between the surface depth r and the fatigue parameter F of the bearing with the most advanced fatigue, where the surface fatigue level is 80%, and the amount to be removed is determined. Therefore, if, for example, the target bearing has a fatigue level of about 50%, there is a possibility that an excess amount of material will be removed.

[0152] Therefore, in Embodiment 18, multiple test pieces of bearings with different fatigue levels are prepared, such as bearings with a fatigue level of 50%, and multiple transition lines corresponding to the relationship between multiple surface depths r and fatigue parameters F are prepared by going through the process of Embodiment 17. Figure 41 is a graph showing examples of multiple transition lines that show the relationship between surface depth r and fatigue parameters F in surface fatigue, which are created in Embodiment 18. Figure 41 shows graphs (fatigue characteristics) for bearings with a fatigue level of 80%, a bearing with a fatigue level of 65%, and a bearing with a fatigue level of 50%. When determining the amount to be removed, eddy current measurements are performed on the bearing to be regenerated, and the graph with the closest characteristic of the surface fatigue level is adopted, thereby reducing the amount of excess removal and determining the optimal amount to be removed. Alternatively, the multiple fatigue characteristics may be linearly interpolated and the graph with the closest characteristic may be adopted.

[0153] In embodiments 17 and 18 described above, the optimal removal amount was determined based on a graph showing the relationship between the amount of fatigue layer removed and the fatigue parameter. However, the removal amount corresponding to the minimum acceptable level at which the fatigue level of the regenerated bearing can exhibit its original bearing performance may also be determined based on a map showing the relationship between the amount of fatigue layer removed and the fatigue level. In this case, multiple sample bearings with different fatigue levels are prepared in advance, and a map is created showing how much removal is needed to reach the acceptable level for each fatigue level. When determining the removal amount, eddy current measurements are performed on the bearing to be regenerated, and the removal amount at which the acceptable level is reached is determined based on the fatigue level data closest to the surface fatigue level. This makes it possible to provide a regenerated bearing that, although not optimal, can exhibit its original bearing performance.

[0154] Based on the above, this disclosure contains at least the following information. Note that the components and other elements corresponding to those in the embodiments described above are indicated in parentheses, but are not limited thereto.

[0155] (1) A method for regenerating a bearing, comprising: an acquisition step (step S121) for obtaining the maximum clearance specification of the bearing to be regenerated; a clearance measurement step (step S122) for measuring the clearance of the bearing before disassembly; a removal step (step S104) for removing the fatigue layer from at least one of the outer ring and inner ring of the bearing; and a calculation step (step S123) for calculating the limit removal amount, which is the upper limit of the total amount of the fatigue layer removed from the mutually opposing surfaces of the outer ring and inner ring, based on the maximum clearance specification and the clearance amount, wherein in the removal step, the fatigue layer is removed within the range of the limit removal amount.

[0156] According to the above configuration, the fatigue layer is removed from the rolling surface of the outer or inner ring within the range of the limit removal amount, thereby suppressing the impact of changes in load conditions on bearing life.

[0157] (2) A bearing regeneration method according to (1), comprising: a measurement step (step S105) of measuring eddy currents on at least one of the outer ring and inner ring from which the fatigue layer has been removed after the removal step; and a determination step (step S106) of determining whether the output voltage value obtained by the eddy current measurement satisfies predetermined conditions, wherein in the determination step, the removal step and the measurement step are repeated until it is determined that the output voltage value satisfies the predetermined conditions, and in the removal step, the fatigue layer is removed such that the cumulative value of the amount of fatigue layer removed is within the range of the limit removal amount.

[0158] According to the above configuration, the fatigue layer is removed within the limits of the removal amount by repeatedly removing the fatigue layer and measuring eddy currents, thus minimizing the amount of removal to the absolute minimum necessary.

[0159] (3) A bearing regeneration method comprising: an acquisition step (step S131) ​​for obtaining the minimum standard value of the assembly width of a single-row tapered roller bearing to be regenerated; an assembly width measurement step (step S132) for measuring the actual assembly width of the single-row tapered roller bearing before disassembly; a removal step (step S104) for removing the fatigue layer from at least one of the outer ring and inner ring of the single-row tapered roller bearing; a calculation step (step S133) for calculating the assembly width limit amount based on the minimum standard value and the actual assembly width; a contact angle measurement step (step S134) for measuring the contact angle of the raceway surface after disassembly; and a calculation step (step S135) for calculating the limit removal amount, which is the limit removal amount of the fatigue layer in the removal step and is the upper limit of the total amount of the fatigue layer removed from the mutually opposing surfaces of the outer ring and the inner ring, wherein in the removal step, the fatigue layer is removed within the range of the limit removal amount.

[0160] According to the above configuration, the fatigue layer is removed from the rolling surface of the outer or inner ring within the range of the limit removal amount, thereby suppressing the impact of changes in load conditions on bearing life.

[0161] (4) A bearing regeneration method according to (3), comprising: a measurement step (step S105) of measuring eddy currents on at least one of the outer ring and inner ring from which the fatigue layer has been removed after the removal step; and a determination step (step S106) of determining whether the output voltage value obtained by the eddy current measurement satisfies predetermined conditions, wherein in the determination step, the removal step, the measurement step and the determination step are repeated until it is determined that the output voltage value satisfies the predetermined conditions, and in the removal step, the fatigue layer is removed such that the cumulative value of the amount of fatigue layer removed is within the range of the limit removal amount.

[0162] According to the above configuration, the fatigue layer is removed within the limits of the removal amount by repeatedly removing the fatigue layer and measuring eddy currents, thus minimizing the amount of removal to the absolute minimum necessary.

[0163] (5) A bearing regeneration method comprising: a measurement step of measuring the effective hardened layer depth of the outer ring and inner ring of a bearing made of carburized steel, respectively; a removal step of removing the fatigue layer of at least one of the outer ring and the inner ring; and a setting step of setting a value obtained by multiplying the effective hardened layer depth by a predetermined coefficient as the limit removal amount of the fatigue layer in the removal step, which is the upper limit of the fatigue layer that is removed from the surface of either the outer ring or the inner ring facing the other, wherein in the removal step, the fatigue layer is removed within the range of the limit removal amount.

[0164] According to the above configuration, the fatigue layer is removed from the rolling surface of the outer or inner ring within the range of the limit removal amount, thereby suppressing the impact of changes in load conditions on bearing life.

[0165] (6) A bearing regeneration method according to (5), comprising: a measurement step (step S105) of measuring eddy currents on at least one of the outer ring and inner ring from which the fatigue layer has been removed after the removal step; and a determination step (step S106) of determining whether the output voltage value obtained by the eddy current measurement satisfies predetermined conditions, wherein in the determination step, the removal step, the measurement step and the determination step are repeated until it is determined that the output voltage value satisfies the predetermined conditions, and in the removal step, the fatigue layer is removed such that the cumulative value of the amount of fatigue layer removed is within the range of the limit removal amount.

[0166] According to the above configuration, the fatigue layer is removed within the limits of the removal amount by repeatedly removing the fatigue layer and measuring eddy currents, thus minimizing the amount of removal to the absolute minimum necessary.

[0167] (7) The bearing regeneration method according to (5), wherein the predetermined coefficient is 0.5.

[0168] According to the above configuration, by setting the limit removal amount to 1 / 2 or less of the effective hardened layer depth, the bearing can withstand the maximum shear stress at a hardness close to the surface hardness, thereby maintaining bearing performance.

[0169] (8) A method for regenerating a bearing as described in (1), wherein, when the bearing is made of carburized steel, the effective hardened layer depth of the outer ring and inner ring of the bearing is measured, and if the value obtained by multiplying the effective hardened layer depth by a predetermined coefficient is smaller than the limit removal amount, the fatigue layer of the corresponding outer ring or inner ring is removed within the range of that value in the removal step, and if the value obtained by multiplying the effective hardened layer depth by a predetermined coefficient is not smaller than the limit removal amount, the fatigue layer is removed within the range of the limit removal amount in the removal step.

[0170] (9) A method for regenerating a bearing as described in (3), wherein, when the bearing is made of carburized steel, the effective hardened layer depth of the outer ring and inner ring of the bearing is measured, and if the value obtained by multiplying the effective hardened layer depth by a predetermined coefficient is smaller than the limit removal amount, the fatigue layer of the corresponding outer ring or inner ring is removed in the removal step within the range of that value, and if the value obtained by multiplying the effective hardened layer depth by a predetermined coefficient is not smaller than the limit removal amount, the fatigue layer is removed in the removal step within the range of the limit removal amount.

[0171] (10) A method for regenerating a bearing according to any one of (2), (4), and (6), wherein in the determination step, a determination map is used to represent the output voltage values ​​obtained by measuring eddy currents for the bearing on the X-Y coordinate axis, and the fatigue degree at each coordinate is associated with the determination map and the output voltage values ​​obtained by measuring eddy currents for the bearing to be regenerated, and it is determined that the predetermined conditions are met if the output voltage value corresponds to a predetermined fatigue degree.

[0172] According to the above configuration, based on the judgment map and the output voltage value, it is possible to gradually remove the fatigue layer until the bearing reaches a predetermined fatigue level.

[0173] (11) A bearing regeneration method according to (10), comprising a pre-determination step (step S102) for determining whether a used bearing is a bearing to be regenerated, wherein the determination map includes a first region, a second region, and a third region divided by fatigue degree, the first region corresponding to a predetermined fatigue degree, the third region corresponding to a fatigue degree higher than the predetermined fatigue degree, and the second region corresponding to a fatigue degree higher than the predetermined fatigue degree and lower than the fatigue degree of the third region, and in the pre-determination step, if the output voltage value obtained by the eddy current measurement of the used bearing falls in the second region of the determination map, it is determined that the used bearing is a bearing to be regenerated.

[0174] According to the above configuration, it is possible to determine whether a used bearing is eligible for refurbishment based on the output voltage value, and if it is determined to be eligible for refurbishment, the fatigue layer can be gradually removed by repeatedly removing the fatigue layer and measuring eddy currents. Therefore, used bearings can be refurbished to maintain their original bearing performance without the user having to determine whether the used bearing is eligible for refurbishment themselves.

[0175] (12) The method for regenerating a bearing according to (11), wherein in the determination step, if the output voltage value obtained by the eddy current measurement for the bearing to be regenerated falls within the first region of the determination map, it is determined that the predetermined conditions are met.

[0176] With the above configuration, the amount of fatigue layer removed can be kept to the absolute minimum necessary by using the judgment map.

[0177] (13) The method for regenerating a bearing according to (10), wherein the predetermined fatigue level is 50% or less.

[0178] According to the above configuration, if the fatigue level is 50% or less, that is, if the fatigue of the material structure and the change in surface properties are very small, there is no problem in using the bearing, and the refurbished bearing can exhibit its original bearing performance.

[0179] (14) The method for regenerating a bearing according to (11), wherein the predetermined fatigue level is 50% or less, the fatigue level of the second region is greater than 50% and 80% or less, and the fatigue level of the third region is greater than 80%.

[0180] The above configuration enables quantitative diagnosis based on specific thresholds. When the fatigue level is 50% or less, the fatigue of the material structure and the change in surface properties are very small, so the bearing can be determined to be usable for continued time. Furthermore, when the fatigue level exceeds 50% but is 80% or less, the fatigue of the material structure progresses predominantly, but since the fatigue can be recovered by removing the fatigue layer, it can be determined to be a target for regeneration (requires repair).

[0181] (15) A method for regenerating a bearing according to any one of (1), (3), and (5), further comprising a step of determining whether or not to remove the fatigue layer by comparing the limit removal amount with the amount of removal required for the fatigue level to reach an acceptable level, after the calculation step and before the removal step.

[0182] According to the above configuration, the fatigue layer removal process is performed only when it is determined that the limit removal amount is greater than the removal amount required to reach the acceptable level. This prevents the bearing regenerated by the fatigue layer removal process from becoming defective (unusable).

[0183] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to these examples. It is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of the present invention. Furthermore, the components of the above embodiments may be combined in any way without departing from the spirit of the invention.

[0184] This application is based on a Japanese patent application (Patent Application No. 2025-015636) filed on January 31, 2025, the contents of which are incorporated herein by reference.

[0185] 1 Reuse Decision Support System 10 Reuse Decision Support Device 20 Measurement Signal Input Unit 21 Probe 22 Switch 23 Input Unit 30 Measurement Signal Acquisition Unit 31 Measurement Switching Unit 32 Data Holding Unit 40 Fatigue Judgment Unit 41 Map Storage Unit 42 Bearing Information Processing Unit 43 Measurement Mode Switching Unit 44 Output Voltage Value Calculation Unit 46 Reuse Judgment Result Display Unit 46a Judgment Unit 46b Presentation Unit 46c Information Acquisition Unit 50 Data Storage Unit (Storage Unit) 51 Basic Information DB 52 New Product Information DB 53 Repair Information DB 54 Insurance Information DB 55 Inventory Information DB 65 Reading Terminal (Reading Unit) 70 Order Processing Unit

Claims

1. A method for regenerating a bearing, comprising: an acquisition step of obtaining the maximum clearance specification of a bearing to be regenerated; a clearance measurement step of measuring the clearance of the bearing before disassembly; a removal step of removing the fatigue layer from at least one of the outer ring and inner ring of the bearing; and a calculation step of calculating the limit removal amount, which is the upper limit of the total amount of the fatigue layer removed from the mutually opposing surfaces of the outer ring and inner ring, based on the maximum clearance specification and the clearance amount, wherein in the removal step, the fatigue layer is removed within the range of the limit removal amount.

2. A bearing regeneration method according to claim 1, comprising: a measurement step of measuring eddy currents on at least one of the outer ring and inner ring from which the fatigue layer has been removed after the removal step; and a determination step of determining whether the output voltage value obtained by the eddy current measurement satisfies predetermined conditions, wherein in the determination step, the removal step and the measurement step are repeated until it is determined that the output voltage value satisfies the predetermined conditions, and in the removal step, the fatigue layer is removed such that the cumulative value of the amount of fatigue layer removed is within the range of the limit removal amount.

3. A bearing regeneration method comprising: an acquisition step of obtaining the minimum standard value of the assembly width of a single-row tapered roller bearing to be regenerated; an assembly width measurement step of measuring the actual assembly width of the single-row tapered roller bearing before disassembly; a removal step of removing the fatigue layer from at least one of the outer ring and inner ring of the single-row tapered roller bearing; a calculation step of calculating the assembly width limit amount based on the minimum standard value and the actual assembly width; a contact angle measurement step of measuring the contact angle of the raceway surface after disassembly; and a calculation step of calculating the limit removal amount, which is the upper limit of the total amount of fatigue layer removed from the mutually opposing surfaces of the outer ring and the inner ring, based on the assembly width limit amount and the contact angle, wherein in the removal step, the fatigue layer is removed within the range of the limit removal amount.

4. A bearing regeneration method according to claim 3, comprising: a measurement step of measuring eddy currents on at least one of the outer ring and inner ring from which the fatigue layer has been removed after the removal step; and a determination step of determining whether the output voltage value obtained by the eddy current measurement satisfies predetermined conditions, wherein in the determination step, the removal step, the measurement step and the determination step are repeated until it is determined that the output voltage value satisfies the predetermined conditions, and in the removal step, the fatigue layer is removed such that the cumulative value of the amount of fatigue layer removed is within the range of the limit removal amount.

5. A bearing regeneration method comprising: a measurement step of measuring the effective hardened layer depth of the outer ring and inner ring of a bearing made of carburized steel, respectively; a removal step of removing the fatigue layer of at least one of the outer ring and inner ring; and a setting step of setting a value obtained by multiplying the effective hardened layer depth by a predetermined coefficient as the limit removal amount of the fatigue layer in the removal step, which is the upper limit of the fatigue layer removed from the surface of either the outer ring or the inner ring facing the other, wherein in the removal step, the fatigue layer is removed within the range of the limit removal amount.

6. A bearing regeneration method according to claim 5, comprising: a measurement step of measuring eddy currents on at least one of the outer ring and inner ring from which the fatigue layer has been removed after the removal step; and a determination step of determining whether the output voltage value obtained by the eddy current measurement satisfies predetermined conditions, wherein in the determination step, the removal step, the measurement step and the determination step are repeated until it is determined that the output voltage value satisfies the predetermined conditions, and in the removal step, the fatigue layer is removed such that the cumulative value of the amount of fatigue layer removed is within the range of the limit removal amount.

7. The bearing regeneration method according to claim 5, wherein the predetermined coefficient is 0.

5.

8. A method for regenerating a bearing according to claim 1, wherein, when the bearing is made of carburized steel, the effective hardened layer depth of the outer ring and inner ring of the bearing is measured, and if the value obtained by multiplying the effective hardened layer depth by a predetermined coefficient is smaller than the limit removal amount, the fatigue layer of the corresponding outer ring or inner ring is removed within the range of that value in the removal step; and if the value obtained by multiplying the effective hardened layer depth by a predetermined coefficient is not smaller than the limit removal amount, the fatigue layer is removed within the range of the limit removal amount in the removal step.

9. A method for regenerating a bearing according to claim 3, wherein, when the bearing is made of carburized steel, the effective hardened layer depth of the outer ring and inner ring of the bearing is measured, and if the value obtained by multiplying the effective hardened layer depth by a predetermined coefficient is smaller than the limit removal amount, the fatigue layer of the corresponding outer ring or inner ring is removed within the range of that value in the removal step; and if the value obtained by multiplying the effective hardened layer depth by a predetermined coefficient is not smaller than the limit removal amount, the fatigue layer is removed within the range of the limit removal amount in the removal step.

10. A method for regenerating a bearing according to any one of claims 2, 4, and 6, wherein in the determination step, a determination map is used to represent the output voltage values ​​obtained by measuring eddy currents for the bearing on an X-Y coordinate axis, and the fatigue degree at each coordinate is associated with the determination map and the output voltage values ​​obtained by measuring eddy currents for the bearing to be regenerated, and it is determined that the predetermined conditions are met if the output voltage value corresponds to a predetermined fatigue degree.

11. A bearing regeneration method according to claim 10, comprising a pre-determination step of determining whether a used bearing is a bearing to be regenerated, wherein the determination map includes a first region, a second region, and a third region divided by fatigue degree, the first region corresponding to a predetermined fatigue degree, the third region corresponding to a fatigue degree higher than the predetermined fatigue degree, and the second region corresponding to a fatigue degree higher than the predetermined fatigue degree and lower than the fatigue degree of the third region, and in the pre-determination step, if the output voltage value obtained by the eddy current measurement of the used bearing falls in the second region of the determination map, it is determined that the used bearing is a bearing to be regenerated.

12. The method for regenerating a bearing according to claim 11, wherein, in the determination step, if the output voltage value obtained by the eddy current measurement for the bearing to be regenerated falls within the first region of the determination map, it is determined that the predetermined conditions are met.

13. The method for regenerating a bearing according to claim 10, wherein the predetermined fatigue level is 50% or less.

14. The method for regenerating a bearing according to claim 11, wherein the predetermined fatigue level is 50% or less, the fatigue level of the second region is greater than 50% and 80% or less, and the fatigue level of the third region is greater than 80%.

15. A method for regenerating a bearing according to any one of claims 1, 3, and 5, further comprising a step of determining whether or not the fatigue layer needs to be removed, after the calculation step and before the removal step.

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