Rolling bearing monitoring method and device

Abstract

The invention provides a rolling bearing monitoring device and a rolling bearing monitoring method capable of finding a peak value more appropriately. A frequency spectrum of vibration data indicating vibration of a rolling bearing is obtained for each sampling period and stored in a storage unit in association with the sampling period, and a specific peak value that does not occur during normal is detected from the frequency spectrum within a first frequency range including a theoretical frequency at which a peak value occurs during abnormality. When a specific peak value is detected, the present invention detects, as a re-detected specific peak value, a specific peak value within a second frequency range, which includes the specific peak value and is narrower than the first frequency range, for one or more frequency spectrums stored in a storage unit (6) before the sampling period, and detects, as a re-detected specific peak value, a specific peak value within a second frequency range which includes the specific peak value and is narrower than the first frequency range. The specific peak value and the re-detection specific peak value are displayed on a display unit.

Description

TECHNICAL FIELD

[0001] The present application relates to a rolling bearing monitoring method and a rolling bearing monitoring device that monitor a rolling bearing. BACKGROUND

[0002] A rolling bearing is a device that supports a load by interposing a rolling element such as a ball, a roller, or the like between two members (a shaft and a track wheel), and is equipped in a device that has a rotating body for various uses. The rolling bearing can be hindered from smooth rolling by abnormalities such as wear (abrasion, scratch), fatigue due to deformation, and fusion due to pressure, for example, and a failure of the aforementioned device can occur. Therefore, it is desirable to monitor the rolling bearing (the state (condition) of the rolling bearing), and a vibration analysis device that performs diagnosis of a rolling bearing is disclosed in Patent Literature 1, for example.

[0003] The vibration analysis device disclosed in Patent Literature 1 is a vibration analysis device that performs diagnosis of a mechanical state based on detected vibration, and includes a setting section that sets a diagnosis target, a rotational speed, and a determination reference value; a condition determination section that determines a diagnosis condition based on information of the diagnosis target; an analysis section that performs frequency analysis on input data; and an abnormality determination section that performs abnormality determination of the diagnosis target based on the determination reference value. In Patent Literature 1, a rolling bearing is cited as the diagnosis target (for example, paragraph

[0018] ), and the abnormality determination section determines a frequency region in which a peak value is expected to appear when damage occurs in the bearing based on a geometric dimension of the bearing (a characteristic frequency of the bearing) that brings about a peak value on a frequency spectrum, and displays a tendency graph of a first peak value that appears near a theoretical frequency (a characteristic frequency of the bearing) when an abnormality occurs (for example, paragraphs

[0056] ,

[0077] , and

[0083] , and FIGS. 12 and 15).

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Publication No. 2022-120875 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] In the foregoing Patent Document 1, in order to determine a frequency region in which a peak is supposed to appear on a frequency spectrum at the time of an abnormality, a theoretical frequency based on the geometric size of a rolling bearing is used. However, in reality, a peak does not necessarily occur at the theoretical frequency at the time of an abnormality, and there are cases in which a peak occurs at a frequency deviating from the foregoing theoretical frequency. Furthermore, in the initial stage of occurrence of a peak related to an abnormality, since the amplitude is small, if other peaks unrelated to the foregoing abnormality occur, distinction between these peaks cannot be made, and it is difficult to find a peak related to an abnormality. That is, when some kind of obstacle that hinders smooth rolling of a rolling bearing occurs in a normal state, detection of a peak occurring due to the foregoing obstacle is difficult in the initial stage, and detection of a peak occurring due to the foregoing obstacle is possible after the foregoing obstacle develops and the amplitude of the peak becomes large. Thus, it is not possible to grasp how the amplitude of a peak occurring due to the foregoing obstacle changes in a period earlier than when the peak can be detected.

[0009] Means for solving the technical problem

[0010] The present inventors have conducted various studies, and as a result, have found that the foregoing object is achieved by the following invention. That is, a rolling bearing monitoring method according to a technical solution of the present invention includes: a frequency spectrum processing step of acquiring vibration data representing vibration occurring in a rolling bearing at a predetermined acquisition interval and for a predetermined sampling period, calculating a frequency spectrum of the vibration data for the sampling period, and storing the calculated frequency spectrum in a storage section in correspondence with the sampling period; a peak detection step of detecting a specific peak that does not occur when the rolling bearing is normal from the frequency spectrum in a predetermined first frequency range including a theoretical frequency that brings about a peak on a frequency spectrum at the time of an abnormality; a peak redetection step of, when a specific peak is detected by the peak detection step, detecting a specific peak that does not occur when the rolling bearing is normal as a redetected specific peak in a predetermined second frequency range narrower than the first frequency range and including the specific peak detected by the peak detection step, from one or more frequency spectra stored in the storage section for a sampling period earlier than the sampling period in which the specific peak is detected; and a display step of displaying, in a display section, time information about the sampling period in which the specific peak is detected by the peak detection step and the amplitude of the detected specific peak, and time information about the sampling period in which the redetected specific peak is detected by the peak redetection step and the amplitude of the detected redetected specific peak. It is preferable that, in the foregoing rolling bearing monitoring method, the first frequency range be set so that the theoretical frequency is a frequency in the center thereof.

[0011] Generally, in a rolling bearing in a normal state, when some kind of obstacle occurs that hinders smooth rolling, after the amplitude of the peak value increases as the aforementioned obstacle develops, the aforementioned peak value can be determined, and the frequency of the peak value can be specified. On the other hand, it is presumed that the peak value before being specified occurs in the vicinity of the specified frequency. The rolling bearing monitoring method described above, since the specified peak value is detected in the first frequency range including the aforementioned theoretical frequency, the specified peak value can be more reliably detected, and the specified peak value is detected again in the second frequency range that is narrower than the aforementioned first frequency range, so the easily confusing peak value that is included in the first frequency range but is not caused by the occurrence of the aforementioned obstacle is excluded from the detection target, and the specified peak value caused by the occurrence of the aforementioned obstacle can be more correctly detected. Furthermore, in the display section, the amplitude of the peak value caused by the obstacle occurring in the rolling bearing is displayed as to what amplitude value it is in the period earlier than the point in time at which the peak value can be detected, and the user can be made to grasp the transition of the past peak value amplitude.

[0012] In another technical solution, in the rolling bearing monitoring method described above, in the case where the peak value re-detection process detects the re-detected specified peak value in the past direction with respect to the plurality of frequency spectra, with respect to each of the plurality of frequency spectra, the peak value detection process and the specified peak value detected by the peak value detection process are each regarded as each initial peak value re-detection process and initial re-detected specified peak value, and for this frequency spectrum, the re-detected specified peak value is detected in the aforementioned second frequency range including the re-detected specified peak value detected by the first aforementioned peak value re-detection process. Preferably, in the rolling bearing monitoring method described above, the second frequency range is set so that the frequency of the re-detected specified peak value is the central frequency. Preferably, in the rolling bearing monitoring method described above, the peak value re-detection process continuously detects the re-detected specified peak value in the past direction with respect to the plurality of frequency spectra in order. Preferably, in the rolling bearing monitoring method described above, the peak value re-detection process discontinuously detects the re-detected specified peak value in the past direction with respect to the plurality of frequency spectra.

[0013] The rolling bearing monitoring method described above, since the re-detected specified peak value is detected in the second frequency range including the re-detected specified peak value detected by the first peak value re-detection process, in the case where the frequency of the re-detected specified peak value changes over time, the re-detected specified peak value can also be more reliably detected.

[0014] In another aspect, in the above-described rolling bearing monitoring method, the display process displays, in the display unit, a coordinate system having a horizontal axis representing time information about the sampling period and a vertical axis representing the amplitude, displays a first coordinate represented by the time information about the sampling period and the amplitude of the detected specific peak in the case where the specific peak is detected by the peak detection process in the display unit, and displays a second coordinate represented by the time information about the sampling period and the amplitude of the detected re-detected specific peak in the case where the re-detected specific peak is detected by the peak re-detection process in the display unit, using a predetermined first mark. Preferably, in the above-described rolling bearing monitoring method, the first mark and the second mark are the same mark. Preferably, in the above-described rolling bearing monitoring method, the first mark and the second mark are different marks from each other.

[0015] Since the time information about the sampling period and the amplitude of the detected specific peak in the case where the specific peak is detected by the peak detection process and the time information about the sampling period and the amplitude of the detected re-detected specific peak in the case where the re-detected specific peak is detected by the peak re-detection process are displayed in the coordinate system, the user (operator) can visually confirm the time variation of the re-detected specific peak and the specific peak, and can visually confirm the development of the above-described abnormality (time variation trend, tendency) in an easily understandable display form.

[0016] In another aspect, in the above-described rolling bearing monitoring method, the peak detection continuation process is a process of detecting, as an exploratory detection specific peak, a specific peak that does not occur when the rolling bearing is normal in a predetermined second frequency range that is narrower than the first frequency range and includes the specific peak, for the frequency spectrum stored in the storage unit at a sampling period later than the sampling period in which the specific peak is detected by the peak detection process. The display process further displays, in the display unit, the sampling period and the amplitude of the detected post-detection specific peak detected by the peak detection continuation process at a sampling period later than the sampling period in which the specific peak is detected.

[0017] Such a rolling bearing monitoring method can detect the specific peak at a sampling period later than the sampling period in which the specific peak is detected by the peak detection process by performing the peak detection continuation process, and can continue the detection of the specific peak.

[0018] In another aspect, in the above-described rolling bearing monitoring method, the peak detection continuation process detects the post-detection specific peak in the second frequency range including the post-detection specific peak detected by the first peak detection continuation process in the sampling period, with respect to the frequency spectrum stored in the storage section in the sampling period.

[0019] Such a rolling bearing monitoring method can more reliably detect the post-detection specific peak in the case where the frequency of the post-detection specific peak changes over time, since the post-detection specific peak is detected in the second frequency range including the post-detection specific peak detected by the first peak detection continuation process.

[0020] In another aspect, in the above-described rolling bearing monitoring method, the display process is a process of displaying an orthogonal coordinate system having a horizontal axis representing time information with respect to the sampling period and a vertical axis representing the amplitude on the display section, displaying a first mark on the display section in the case where the first coordinate represented by the time information with respect to the sampling period and the amplitude of the detected specific peak is detected by the peak detection process, displaying a second mark on the display section in the case where the second coordinate represented by the time information with respect to the sampling period and the amplitude of the detected re-detection specific peak is detected by the peak re-detection process, and displaying a third mark on the display section in the case where the third coordinate represented by the time information with respect to the sampling period and the amplitude of the detected post-detection specific peak is detected by the peak detection continuation process. Preferably, in the above-described rolling bearing monitoring method, the first mark, the second mark, and the third mark are the same mark. Preferably, in the above-described rolling bearing monitoring method, the first mark, the second mark, and the third mark are mutually different marks. Preferably, in the above-described rolling bearing monitoring method, the first mark, the second mark, and the third mark are partially the same mark.

[0021] Such a rolling bearing monitoring method enables a user (operator) to visually confirm the time variation of the re-detection specific peak value, the specific peak value, and the post-detection specific peak value, and the development state (time variation tendency, trend) of the obstacle, in an easily understood display form, since the time information about the sampling period and the amplitude of the detected specific peak value in the case where the specific peak value is detected by the aforementioned peak value detection process, the time information about the sampling period and the amplitude of the detected re-detection specific peak value in the case where the re-detection specific peak value is detected by the aforementioned peak value re-detection process, and the time information about the sampling period and the amplitude of the detected post-detection specific peak value in the case where the post-detection specific peak value is detected by the aforementioned peak value detection continuation process are displayed in the orthogonal coordinate system.

[0022] In another aspect, in the above-described rolling bearing monitoring method, the length of the sampling period is set based on the second frequency range, and the narrower the second frequency range, the longer the sampling period is set.

[0023] Such a rolling bearing monitoring method enables a peak value to be detected from the frequency spectrum data with an appropriate frequency resolution corresponding to the range of the second frequency range.

[0024] A rolling bearing monitoring device according to another aspect of the present application includes a vibration detection sensor that acquires vibration data representing vibration generated by a rolling bearing; a storage unit; a control processing unit that performs frequency spectrum processing, peak value detection processing, peak value re-detection processing, and display processing; and a display unit; the frequency spectrum processing is processing of acquiring, at a predetermined sampling period and at a predetermined acquisition interval, a frequency spectrum of the vibration data in the sampling period, storing the frequency spectrum thus obtained in the storage unit in association with the sampling period; the peak value detection processing is processing of detecting, from the frequency spectrum, a specific peak value that does not occur when the rolling bearing is normal, in a predetermined first frequency range that includes a theoretical frequency at which a peak value is brought on the frequency spectrum when an abnormality occurs; the peak value re-detection processing is processing of, in the case where a specific peak value is detected by the peak value detection processing, detecting, as a re-detection specific peak value, a specific peak value that does not occur when the rolling bearing is normal, in a predetermined second frequency range that is narrower than the first frequency range and that includes the frequency of the specific peak value detected by the peak value detection processing, from one or more frequency spectrums stored in the storage unit before the sampling period in which the specific peak value is detected; and the display processing is processing of displaying, in the display unit, the time information about the sampling period and the amplitude of the detected specific peak value in the case where the specific peak value is detected by the peak value detection processing, and the time information about the sampling period and the amplitude of the detected re-detection specific peak value in the case where the re-detection specific peak value is detected by the peak value re-detection processing.

[0025] Such a rolling bearing monitoring device can more appropriately find a peak value (a specific peak value and a re-detected specific peak value).

[0026] Inventive Effects

[0027] The rolling bearing monitoring method and the rolling bearing monitoring device relating to the present application display, in a display section, an amplitude value of a peak value occurring due to an obstacle generated in a rolling bearing, in a period earlier than a time point at which the peak value can be detected, and enable a user to grasp a progress of a past peak value amplitude. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a block diagram showing a structure of a rolling bearing monitoring device of an embodiment.

[0029] Figure 2 is a graph for explaining a predetermined time length in vibration data.

[0030] Figure 3 is a graph for explaining a mechanical device equipped with a rolling bearing.

[0031] Figure 4 is a graph for explaining a first and a second frequency range.

[0032] Figure 5 is a graph for explaining a display screen of a peak value (a specific peak value and a re-detected specific peak value) as an example.

[0033] Figure 6 is a flowchart showing an operation of the aforementioned rolling bearing monitoring device relating to a period before a specific peak value is detected.

[0034] Figure 7 is a flowchart showing an operation of the aforementioned rolling bearing monitoring device relating to a period after the aforementioned specific peak value is detected.

[0035] Figure 8 is a block diagram showing a structure of a rolling bearing monitoring device of a modification of the embodiment. DETAILED DESCRIPTION

[0036] Hereinafter, one or more embodiments of the present application will be described with reference to the accompanying drawings. However, the scope of the present application is not limited to the disclosed embodiments. In addition, structures indicated by the same reference numerals in each drawing represent the same structures, and the description thereof will be appropriately omitted. In the present specification, reference numerals without a subscript indicate a general reference numeral, and reference numerals with a subscript indicate a separate structure.

[0037] Figure 1 is a block diagram showing a structure of a rolling bearing monitoring device of an embodiment. Figure 2is a graph for explaining a predetermined time length in vibration data. Figure 3 is a graph for explaining a mechanical device equipped with a rolling bearing. Figure 4 is a graph for explaining a first and a second frequency range. Figure 4 A indicates a first frequency range, Figure 4 B indicates a second frequency range. Figure 4 A and Figure 4 Each horizontal axis of each graph of A and Figure 5 is a graph for explaining a display screen of a peak value (a specific peak value and a re-detection specific peak value) as an example. Figure 5 A indicates a case of a mechanical device of a first example, Figure 5 B indicates a case of a mechanical device of a second example.

[0038] The rolling bearing monitoring device 1000 of the embodiment, for example, as shown in Figure 1 , is equipped with a vibration detection sensor 1, a control processing section 2, an input section 3, a display section 4, an interface section (IF section) 5, and a storage section 6.

[0039] The vibration detection sensor 1 is connected to the control processing section 2, and is a device that acquires vibration data indicating vibration generated in a rolling bearing in accordance with control by the control processing section 2. In the present embodiment, a plurality of vibration data acquired at a predetermined acquisition interval in a predetermined sampling period by the vibration detection sensor 1 that detects vibration generated in a rolling bearing is stored in the storage section 6.

[0040] As described later, vibration data is transformed from a time space to a frequency space by high-speed Fourier transform. In this case, frequency resolution of a frequency spectrum depends on a data point number used at the time of high-speed Fourier transform. The more the aforementioned data point number, the higher the frequency resolution, and the more vibration data of the aforementioned predetermined sampling period corresponding thereto is required. Here, in a case where a sampling interval is SP, a data point number is Nfft, and a length of the aforementioned predetermined sampling period is TW, TW = SP x Nfft is obtained. The length TW of the aforementioned predetermined sampling period is set based on a second frequency range FW2 described later in the present embodiment, and the more narrow the aforementioned second frequency range, the longer the period to which the aforementioned sampling period is set. In order to detect a meaningful peak value in the second frequency range ±△fw2, for example, as Figure 2As shown, the second frequency range ±Δfw2 (=2×Δfw2) needs to be set to 4 or more. Therefore, the frequency resolution is 2×Δfw2 / 4=Δfw2 / 2 [Hz] or more, and thus, the length of the aforementioned predetermined sampling period TW is its reciprocal 2 / Δfw2 [seconds] or more. For example, when Δfw2 is set to 0.02 [Hz] and the sampling interval SP is set to 0.2 [ms] (=0.0002 [s]), the length of the aforementioned predetermined sampling period TW is TW=2 / 0.02=100 [s] or more, and the number of data points Nfft is Nfft=100 / 0.0002=500000 [points] or more. Since the high-speed Fourier transform generally handles the number of powers of 2, the minimum number of powers exceeding 500,000 is 2^19 = 524,288. The length of the aforementioned sampling period TW is TW = 0.0002 × 524,288 = 104.8576 s.

[0041] The aforementioned vibration detection sensor 1 is one or more, and is configured in a device that includes a rolling bearing, such as mechanical equipment. The aforementioned mechanical equipment is an example of a device equipped with a rolling bearing; any device can be used as long as it includes a rolling bearing. For example, the aforementioned mechanical equipment M is... Figure 3 The reducer M shown generally includes first to third rolling bearings BE-1 to BE-3, first and second rotating shafts AX-1 and AX-2, first and second gears GA-1 and GA-2, and a schematic housing (shell) that houses these first to third rolling bearings BE-1 to BE-3, first and second rotating shafts AX-1 and AX-2, and first and second gears GA-1 and GA-2. The first rotating shaft AX-1 is fixed to the first gear GA-1 and is the rotating shaft of the first gear GA-1, supported by the first rolling bearing BE-1. The second rotating shaft AX-2 is fixed to the second gear GA-2 and is the rotating shaft of the second gear GA-2, supported by the second and third rolling bearings BE-2 and BE-3. The first gear GA-1 meshes with the second gear GA-2. For example, the rotational force generated by the rotation of the first rotating shaft AX-1 is transmitted to the second rotating shaft AX-2 via the first and second gears GA-1 and GA-2, and the second rotating shaft AX-2 rotates.

[0042] The vibration detection sensor 1 has three first to third vibration detection sensors 1-1 to 1-3 for such a structure of the speed reducer M. The first to third vibration detection sensors 1-1 to 1-3 are respectively arranged on each outer circumference of the first to third rolling bearings BE-1 to BE-3. In addition, the vibration detection sensor 1 (1-1 to 1-3) is not limited to the rolling bearings BE, but can be arranged in the aforementioned housing, for example. In any case, the first to third vibration detection sensors 1-1 to 1-3 are arranged at positions where vibrations caused by the rolling bearings BE propagate. Such first to third vibration detection sensors 1-1 to 1-3 are, for example, acceleration sensors, AE (Acoustic Emission) sensors, or the like, and appropriate sensors are used depending on the frequency of vibrations generated in the monitoring object. The first to third vibration detection sensors 1-1 to 1-3 output detection results to the control processing portion 2 in this embodiment.

[0043] In this embodiment, for example, if the control processing portion 2 becomes the start point of the predetermined sampling period, the control processing portion 2 instructs the first to third vibration detection sensors 1-1 to 1-3 to acquire the aforementioned vibration data, and in response to the instruction, the first to third vibration detection sensors 1-1 to 1-3 detect vibrations at each sampling point corresponding to the predetermined sampling interval, and output vibration data of the length TW of the aforementioned predetermined sampling period to the control processing portion 2. The control processing portion 2 stores and saves the aforementioned vibration data in the storage portion 6 in association with the aforementioned sampling period (for example, the start time of the sampling period).

[0044] The input portion 3 is connected to the control processing portion 2, and is, for example, a device that inputs various commands such as a command to instruct the start of monitoring, and various data such as the name of the mechanical equipment of the monitoring object required to operate the rolling bearing monitoring device 1000, and is, for example, a plurality of input switches, a keyboard, a mouse, or the like, to which a predetermined function is assigned. The display portion 4 is connected to the control processing portion 2, and is a device that displays commands, data, and monitoring results, or the like, input from the input portion 3, in accordance with the control of the control processing portion 2, and is, for example, a display device such as a CRT display, a liquid crystal display, and an organic EL display.

[0045] In addition, the input section 3 and the display section 4 can also constitute a so-called touch panel. In the case of constituting the touch panel, the input section 3 is a position input device that detects an operation position in, for example, a resistive film method, an electrostatic capacity method, or the like, and inputs the position. In the touch panel, the aforementioned position input device is provided on the display surface of the display section 4, and the display section 4 displays candidates of one or a plurality of input contents that can be input. If the user touches a display position at which an input content that the user wants to input is displayed, the position of the display position is detected by the aforementioned position input device, and the display content displayed at the detected position is input to the rolling bearing monitoring device 1000 as the operation input content of the user. In such a touch panel, since the user can easily intuitively understand the input operation, it is possible to provide the rolling bearing monitoring device 1000 that is easy to operate for the user.

[0046] The IF section 5 is connected to the control processing section 2, and is a circuit that performs input and output of data between the external device in accordance with the control of the control processing section 2, and is, for example, an interface circuit for an RS-232C of a serial communication method, an interface circuit using a Bluetooth (registered trademark) specification, an interface circuit that performs infrared communication of an IrDA (Infrared Data Association) specification, and an interface circuit using a USB (Universal Serial Bus) specification, or the like. In addition, the IF section 5 is a circuit that performs communication between the external device, and can also be, for example, a data communication card, a communication interface circuit that complies with an IEEE 802.11 specification, or the like.

[0047] The storage section 6 is connected to the control processing section 2 and is a circuit that stores various predetermined programs and various predetermined data in accordance with the control of the control processing section 2. The various predetermined programs include, for example, a control processing program, and the control processing program includes a control program, a spectrum processing program, a peak detection program, a peak re-detection program, a peak detection continuation program, and a display processing program. The control program is a program that controls each of the sections 1, 3 to 6 of the rolling bearing monitoring device 1000 in accordance with the function of each section. The spectrum processing program is a program that acquires a plurality of vibration data different from each other in a plurality of sampling periods different from each other, respectively, from the vibration detection sensor 1, calculates a frequency spectrum of the vibration data in each of the sampling periods, respectively, and stores the calculated frequency spectrum in the storage section 6 in correspondence with the sampling period. The peak detection program is a program that detects a specific peak that does not occur at a normal time of the rolling bearing in a predetermined first frequency range including a theoretical frequency that brings a peak on a frequency spectrum at the time of an abnormality in the frequency spectrum. The peak re-detection program is a program that, in the case where the specific peak is detected by the peak detection program, detects a specific peak that does not occur at a normal time of the rolling bearing as a re-detected specific peak in a predetermined second frequency range narrower than the first frequency range and including a frequency of the specific peak detected by the peak detection program, from one or a plurality of frequency spectra stored in the storage section 6 in correspondence with a sampling period earlier than the sampling period in which the specific peak is detected. The peak detection continuation program is a program that, in the case where the specific peak is detected by the peak detection program, detects a specific peak that does not occur at a normal time of the rolling bearing as a detected later specific peak in the predetermined second frequency range and including the frequency of the specific peak, from a frequency spectrum stored in the storage section 6 in a sampling period later than the sampling period in which the specific peak is detected, with respect to the frequency spectrum. The display processing program is a program that displays time information (for example, a part of date and time information) with respect to a sampling period in which the specific peak is detected by the peak detection program and an amplitude of the detected specific peak, and time information (for example, a part of date and time information) with respect to a sampling period in which the re-detected specific peak is detected by the peak re-detection program and an amplitude of the detected re-detected specific peak, on the display section 4. The various predetermined data include, for example, data required for executing each of the programs, such as a frequency spectrum in correspondence with the time information with respect to the sampling period, a theoretical frequency, a first frequency range, a second frequency range, a specific peak, and a re-detected specific peak.Such a storage section 6 has, for example, a ROM (Read Only Memory) that is a nonvolatile storage element, an EEPROM (Electrically Erasable Programmable Read Only Memory) that is a rewritable nonvolatile storage element, and the like. Furthermore, the storage section 6 includes a RAM (Random Access Memory) that is a work memory of the so-called control processing section 2, which stores data and the like generated in execution of the aforementioned predetermined program, and the like. In addition, the storage section 6 can also have a hard disk device (HHD) that can store a relatively large capacity, a solid state drive (SSD), and the like.

[0048] The control processing section 2 is a circuit for monitoring the rolling bearing BE (the state (condition) of the rolling bearing BE) that controls each of the sections 1, 3 to 6 of the rolling bearing monitoring device 1000 in accordance with the function of each section. The control processing section 2 is configured to have, for example, a CPU (Central Processing Unit) and a peripheral circuit thereof. By executing the aforementioned control processing program by the control processing section 2, a control section 21, a spectrum processing section 22, a peak detection section 23, a peak re-detection section 24, a peak detection continuation section 25, and a display processing section 26 are functionally configured.

[0049] The control section 21 controls each of the sections 1, 3 to 6 of the rolling bearing monitoring device 1000 in accordance with the function of each section, and is responsible for the control of the entire rolling bearing monitoring device 1000.

[0050] The spectrum processing section 22 performs spectrum processing of acquiring vibration data in each of a plurality of sampling periods different from each other by the vibration detection sensors 1, calculating a frequency spectrum of the vibration data in the respective sampling periods for the plurality of sampling periods, and storing the calculated frequency spectrum in correspondence with the sampling period to the storage section 6. More specifically, in the spectrum processing section, if it is the start point of the sampling period that becomes the predetermined acquisition interval, vibration data is acquired by the first to third vibration detection sensors 1-1 to 1-3 respectively for the length TW of the sampling period that is the predetermined sampling period, and stored to the storage section 6, and the spectrum processing section 22 acquires the vibration data for this sampling period. Next, the spectrum processing section 22 transforms the time-space vibration data acquired by the first vibration detection sensor 1-1 into frequency-space vibration data by high-speed Fourier transform (FFT), for example, calculates the frequency spectrum of the vibration data, and stores it in correspondence with the sampling period and the first vibration detection sensor 1-1 (for example, the identifier (sensor ID) of the first vibration detection sensor 1-1) to the storage section 6. Next, likewise, the spectrum processing section 22 transforms the time-space vibration data acquired by the second vibration detection sensor 1-2 into frequency-space vibration data by the aforementioned FFT, calculates the frequency spectrum of the vibration data, and stores it in correspondence with the sampling period and the second vibration detection sensor 1-2 (for example, the identifier (sensor ID) of the second vibration detection sensor 1-2) to the storage section 6. Also, likewise, the spectrum processing section 22 transforms the time-space vibration data acquired by the third vibration detection sensor 1-3 into frequency-space vibration data by the aforementioned FFT, calculates the frequency spectrum of the vibration data, and stores it in correspondence with the sampling period and the third vibration detection sensor 1-3 (for example, the identifier (sensor ID) of the third vibration detection sensor 1-3) to the storage section 6. Such processing is repeated at the start point of the sampling period of the predetermined acquisition interval. The aforementioned acquisition interval is appropriately set in advance, for example, in accordance with the life of the monitoring target, and the like. The life of the rolling bearing can be predicted, for example, in accordance with the load and the rotational speed, and the like. For example, in the case where the aforementioned monitoring target is a rolling bearing that accommodates a shaft that is relatively intensively used, such as a shaft that is rotated at high speed by frequent operation, the aforementioned acquisition interval is set to a relatively short period of time, such as 1 hour, 1 day, and the like, or, for example, in the case where the aforementioned monitoring target is a rolling bearing that accommodates a shaft that is relatively gently used, such as a shaft that is rotated relatively gently, the aforementioned acquisition interval is set to a relatively long period of time, such as 1 month, half a year, and the like. The start point of the sampling period is represented by a continuous number from the start of the acquisition of the aforementioned vibration data, the time of the aforementioned start point, and the like, for example.

[0051] The peak detection section 23, when storing the aforementioned frequency spectrum into the aforementioned storage section 6, performs a peak detection process of detecting a specific peak value that does not occur at the time of normality of the rolling bearing, from the aforementioned frequency spectrum, in a predetermined first frequency range that includes a theoretical frequency that brings a peak value on the frequency spectrum at the time of abnormality. The peak detection section 23, in the case where a specific peak value is detected, stores the sampling period, the amplitude, and the frequency of the detected specific peak value into the storage section 6.

[0052] The aforementioned theoretical frequency ft that brings a peak value on the frequency spectrum at the time of abnormality is known, and differs depending on the site of occurrence of damage (bearing damage) of the rolling bearing, and is, for example, as in Table 1 below. The aforementioned site of bearing damage is, for example, the inner ring, the outer ring, the rolling element, and the retainer. Here, fti is the theoretical frequency in the case where bearing damage has occurred in the inner ring, fto is the theoretical frequency in the case where bearing damage has occurred in the outer ring, ftb is the theoretical frequency in the case where bearing damage has occurred in the rolling element, and ftm is the theoretical frequency in the case where bearing damage has occurred in the retainer. d is the diameter of the rolling element, D is the pitch diameter of the rolling element, Z is the number of rolling elements, and a is the contact angle.

[0053] [Table 1]

[0054]

[0055] The frequency of the peak value that occurs on the frequency spectrum due to some kind of obstacle that hinders smooth rolling of the rolling bearing in the normal state (for example, a rolling bearing that has not been used, etc.) does not actually coincide with the theoretical frequency, due to dimensional tolerance of the rolling bearing, deformation by load, etc. Therefore, in order to detect the unclear peak value that occurs on the aforementioned frequency spectrum, a predetermined first frequency range that includes the aforementioned theoretical frequency ft is appropriately set in advance. For example, as shown in FIG. A, the first frequency range FW1 has a frequency ft set as the center thereof (ft - Δfw1 ≤ FW1 ≤ ft + Δfw1, Δfw1 is, for example, about 1 to 5 [%] of ft). Figure 4 A shown, the first frequency range FW1 has a frequency ft set as the center thereof (ft - Δfw1 ≤ FW1 ≤ ft + Δfw1, Δfw1 is, for example, about 1 to 5 [%] of ft).

[0056] In the detection of the specific peak value (peak value due to the aforementioned obstacle) that does not occur at the time of normality of the aforementioned rolling bearing, for example, a peak value is detected in the first frequency range FW1, and in the case where a peak value (high-order harmonic) also exists at a frequency that is an integral multiple of the frequency of the aforementioned detected peak value (for example, a frequency that is twice, a frequency that is three times, etc.), the aforementioned detected peak value is set as the specific peak value, and it is determined that the aforementioned specific peak value has been detected, and in the case where a peak value does not exist at a frequency that is an integral multiple of the frequency of the aforementioned detected peak value, it is determined that the aforementioned detected peak value is not the specific peak value, and it is determined that the aforementioned specific peak value has not been detected. For example, in the case where a peak value exists at a frequency that is twice the frequency of the detected peak value, it is determined that the detected peak value is the specific peak value, and in the case where a peak value does not exist at a frequency that is twice the frequency of the detected peak value, it is determined that the detected peak value is not the specific peak value. Figure 4In A, in a case where a peak PK1 and a peak PK2 are detected in the first frequency range FW1, and a peak characteristic of a bearing damage vibration with respect to the frequency fpl of the peak PK1 does not have a peak at an integral multiple of the frequency, and on the other hand, a peak is present at an integral multiple of the frequency fp2 of the peak PK2, the peak PK1 is determined not to be a specific peak, and on the other hand, the peak PK2 is determined to be a specific peak, and it is determined that a specific peak is detected. In this embodiment, since the first to third vibration detection sensors 1-1 to 1-3 are used, in a case where a specific peak is determined in a common frequency in two or more frequency spectra among the first to third vibration detection sensors 1-1 to 1-3, it is finally determined that a specific peak is detected.

[0057] The peak re-detection section 24, in a case where a specific peak is detected by the aforementioned peak detection section 23, performs, for one or more frequency spectra stored in the aforementioned storage section 6 in advance of the sampling period at which the aforementioned specific peak is detected, a peak re-detection process of detecting a specific peak that is not present at normal times as a re-detection specific peak within a predetermined second frequency range FW2 that is narrower than the aforementioned first frequency range FW1 and that includes the frequency of the aforementioned specific peak detected by the aforementioned peak detection section 23. The peak re-detection section 24 stores the sampling period, the amplitude, and the frequency of the detected re-detection specific peak to the storage section 6.

[0058] Typically, when a rolling bearing in its normal state encounters an obstacle that hinders smooth rolling, the peak value can be determined after the amplitude of the peak increases as the obstacle develops. Therefore, it is possible that a specific peak value exists earlier than the sampling period during which the specific peak value was first detected. The peak re-detection unit 24 detects the specific peak value earlier than the sampling period during which the specific peak value was first detected as a re-detected specific peak value. Therefore, the peak re-detection unit 24 can also detect the specific peak value as a re-detected specific peak value for one frequency spectrum stored in the storage unit 6 earlier than the sampling period of the frequency spectrum in which the specific peak value was detected by the peak detection unit 23, or it can detect the specific peak value as a re-detected specific peak value for some frequency spectra (a few frequency spectra less than all) of all frequency spectra stored in the storage unit 6 earlier than the sampling period, or it can detect the specific peak value as a re-detected specific peak value for all frequency spectra stored in the storage unit 6 earlier than the sampling period. When detecting the aforementioned specific peak as a re-detection specific peak for multiple frequency spectra, the peak re-detection unit 24 may, for example, continuously and sequentially detect the aforementioned re-detection specific peak in the past direction relative to the aforementioned multiple frequency spectra, or, for example, the peak re-detection unit 24 may detect the aforementioned re-detection specific peak discontinuously in the past direction relative to the aforementioned multiple frequency spectra. In this embodiment, the peak re-detection unit 24 continuously and sequentially retrieves a predetermined number of frequency spectra stored in the storage unit 6 corresponding to a predetermined number of sampling periods earlier than the aforementioned sampling period, and continuously and sequentially detects the aforementioned re-detection specific peak in the past direction for the aforementioned predetermined number of retrieved frequency spectra.

[0059] As described above, the peak value can usually be determined after the amplitude of the peak increases due to the development of the aforementioned obstacle. Therefore, the frequency of the specific peak value is unknown before it is detected by the peak detection unit 23, so it is usually necessary to set the first frequency range FW1 relatively wide. On the other hand, it is assumed that the specific peak value before it is determined occurs around the frequency at which it is determined. Therefore, a predetermined second frequency range, which includes the frequency of the aforementioned specific peak value and is narrower than the first frequency range FW1, is appropriately set in advance. For example, as Figure 4 As shown in B, the frequency fp2 of the specific peak PK2 of the second frequency range FW2 is set as its center frequency (fp2-△fw2≤FW2≤fp2+△fw2, △fw2 is, for example, about 0.1 to 0.5% of the theoretical frequency ft).

[0060] In the aforementioned detection of specific peak values, the peak value that has the maximum amplitude within the aforementioned second frequency range FW2 and also has peak values ​​in integer multiples of that frequency is defined as the specific peak value to be detected. For example, in Figure 4In B, a peak value PK2' that is the maximum amplitude in the second frequency range FW2 and that also has a peak value at an integral multiple of the frequency is set as the re-detection specific peak value.

[0061] The second frequency range FW2 can be the same in the case where the re-detection specific peak value is detected from the plurality of frequency spectra, but in the present embodiment, the peak value re-detection section 24, in the case where the re-detection specific peak value is detected in the past direction with respect to the plurality of frequency spectra, for each of the plurality of frequency spectra, regards each of the specific peak values detected in the peak value detection processing and the peak value detection processing as each of the initial peak value re-detection processing and the initial re-detection specific peak value, and for that frequency spectrum, detects the re-detection specific peak value in the second frequency range FW2 that contains the re-detection specific peak value detected in the first of the peak value re-detection processing. For example, even if a deviation occurs in the frequency of the re-detection specific peak value due to wear or the like, the re-detection specific peak value can be detected.

[0062] The peak value detection continuation section 25, in the case where a specific peak value is detected by the peak value detection processing, for the frequency spectrum stored in the storage section 6 at the time of the detection, performs peak value detection continuation processing that detects a specific peak value that does not occur at the time of normality of the rolling bearing in a second frequency range FW2 that contains the frequency of the specific peak value and that is narrower than the first frequency range FW1, as a post-detection specific peak value, at a sampling period later than the sampling period at the time of detection of the specific peak value. The peak value detection continuation section 25 stores the sampling period, the amplitude, and the frequency of the detected post-detection specific peak value in the storage section 6.

[0063] In the detection of the post-detection specific peak value, as with the detection of the specific peak value, in the case where a peak value is detected in the second frequency range FW2 and a peak value also exists at an integral multiple of the frequency, the peak value can be set as the post-detection specific peak value, or a peak value of the maximum amplitude in the second frequency range FW2 can be set as the post-detection specific peak value.

[0064] The second frequency range FW2 can be the same in the case where the post-detection specific peak value is detected at a sampling period later than the sampling period at the time of detection of the specific peak value, but in the present embodiment, the peak value detection continuation section 25 regards the specific peak values detected by the peak value detection processing and the peak value detection processing as the initial peak value detection continuation processing and the initial post-detection specific peak value, respectively, and for the frequency spectrum stored in the storage section 6 at the sampling period, detects the post-detection specific peak value in the second frequency range that contains the post-detection specific peak value detected by the first of the peak value detection continuation processing of the sampling period. For example, in the case where a deviation occurs in the frequency of the post-detection specific peak value due to wear or the like, the post-detection specific peak value can be detected.

[0065] The display processing unit 26 performs display processing, displaying time information regarding the sampling period and the amplitude of the detected specific peak when the peak detection unit 23 detects a specific peak, and time information regarding the sampling period and the amplitude of the detected specific peak when the peak re-detection unit 24 detects a re-detected specific peak. In this embodiment, the aforementioned display processing also involves displaying time information regarding the sampling period following the sampling period after the detection of the specific peak and the amplitude of the detected post-detection specific peak detected by the peak detection continuation processing on the display unit 4. More specifically, assuming the acquisition interval is every day as an example, the display processing unit 26 displays an orthogonal coordinate system on the display unit 4, with the horizontal axis representing the date (time information related to the sampling period) and the vertical axis representing the amplitude. If a specific peak is detected by the peak detection processing, a first coordinate representing the date and the amplitude of the detected specific peak is displayed as a predetermined first mark on the display unit 4. If a re-detection of the specific peak is detected by the peak re-detection processing, a second coordinate representing the date and the amplitude of the re-detected specific peak is displayed as a predetermined second mark on the display unit 4. If a post-detection specific peak is detected by the peak detection continuation processing, a third coordinate representing the date and the amplitude of the post-detection specific peak is displayed as a predetermined third mark on the display unit 4. The first, second, and third marks may be the same, different from each other, or partially the same.

[0066] When the peak re-detection unit 24 detects one re-detected specific peak using one frequency spectrum, the display processing unit 26 displays the specific peak detected by the peak detection unit 23 and the one re-detected specific peak detected by the peak re-detection unit 24 on the display unit 4. When the peak re-detection unit 24 detects multiple re-detected specific peaks using multiple frequency spectra, the display processing unit 26 displays the specific peak detected by the peak detection unit 23 and the multiple re-detected specific peaks detected by the peak re-detection unit 24 on the display unit 4. During the sampling period after the peak detection unit 23 initially detects the specific peak, the one or more re-detected specific peaks, and the post-detection peaks detected after the aforementioned initially detected specific peaks on the display unit 4.

[0067] For example, the display processing unit 26 will Figure 5 The displayed screen is shown on display unit 4. Figure 5 A represents the mechanical equipment in the first example. Figure 5 B represents the mechanical equipment in the second example.

[0068] exist Figure 5In A, an example is shown in which the date with respect to the sampling period this time is the time point TD+1, and the specific peak is initially detected at a time point TD0 which is 1 time point before the time point TD+1. Further, it is assumed that in the peak re-detection processing, 4 frequency spectra are taken back in the past direction to be detected.

[0069] In Figure 5 In the example shown in A, with respect to the frequency spectrum of the time point TD-1 which is 1 time point before the time point TD0, the peak re-detection section 24 performs the re-detection processing in the 2nd frequency range FW2 which includes the specific peak detected by the peak detection section 23, for example, indicated by •, and detects the re-detection specific peak of the time point TD-1, for example, indicated by x. Next, with respect to the frequency spectrum of the time point TD-2 which is 1 time point before the time point TD-1, the peak re-detection section 24 performs the re-detection processing in the 2nd frequency range FW2 which includes the re-detection specific peak x of the time point TD-1, and detects the re-detection specific peak of the time point TD-2, for example, indicated by x. Next, with respect to the frequency spectrum of the time point TD-3 which is 1 time point before the time point TD-2, the peak re-detection section 24 performs the re-detection processing in the 2nd frequency range FW2 which includes the re-detection specific peak x of the time point TD-2. In this Figure 5 In the example shown in A, no peak is detected from the frequency spectrum of the time point TD-3. Next, with respect to the frequency spectrum of the time point TD-4 which is 1 time point before the time point TD-3, the peak re-detection section 24 performs the re-detection processing in the 2nd frequency range FW2 which includes the re-detection specific peak x of the time point TD-3. In this Figure 5 In the example shown in A, no peak is detected from the frequency spectrum of the time point TD-4. If the detection time point TD+1 becomes a time point after the time point TD0, with respect to the frequency spectrum of the time point TD+1, the peak detection continuation section 25 performs the peak detection continuation processing of the time point TD+1 in the 2nd frequency range FW2 which includes the specific peak • of the time point TD0, and detects the post-detection specific peak of the time point TD+1, for example, indicated by x. Further, the display processing section 26 displays the 2nd and 3rd marks x in the display section 4, and displays the 1st mark • in the display section 4. Figure 5 In A, the orthogonal coordinate system is displayed in the display section 4 with the horizontal axis as the date with respect to the sampling period, and the vertical axis as the amplitude, the 1st mark • is displayed in the display section 4 at the coordinates of the time point TD0 and the amplitude of the specific peak thereof, the respective 2nd marks x are displayed in the display section 4 at the coordinates of the time point TD-1 and the amplitude of the re-detection specific peak thereof, and at the coordinates of the time point TD-2 and the amplitude of the re-detection specific peak thereof, and the 3rd mark x is displayed in the display section 4 at the coordinates of the time point TD+1 and the amplitude of the post-detection specific peak thereof. In Figure 5 In the example shown in A, the 2nd and 3rd marks are the same mark x, and the 1st mark is a different mark • from the 2nd and 3rd marks.

[0070] Further, in Figure 5In the example shown in A, the display processing section 26 finds a fitting curve α that best fits the date and amplitude with respect to the sampling period of the specific peak value before, the date and amplitude with respect to the sampling period of the specific peak value after detection, and the date and amplitude with respect to the sampling period of the specific peak value after re-detection, and displays the found fitting curve α in the display section 4 in a coordinate space with time and amplitude as the coordinate axes.

[0071] In Figure 5 In B, an example is shown in which the time point this time is the time point TD+3, and the specific peak value was initially detected at the time point TD0, which is 3 hours before the time point TD+3.

[0072] In Figure 5In the example shown in FIG. B, for the frequency spectrum at the time point TD-1 which is one time point before the time point TD0, the peak re-detection section 24 performs a re-detection process in the second frequency range FW2 which includes the specific peak indicated by • detected by the peak detection section 23, and detects a re-detection specific peak at the time point TD-1 indicated by o. Next, for the frequency spectrum at the time point TD-2 which is one time point before the time point TD-1, the peak re-detection section 24 performs a re-detection process in the second frequency range FW2 which includes the re-detection specific peak o at the time point TD-1, and detects a re-detection specific peak at the time point TD-2 indicated by o. Next, for the frequency spectrum at the time point TD-3 which is one time point before the time point TD-2, the peak re-detection section 24 performs a re-detection process in the second frequency range FW2 which includes the re-detection specific peak o at the time point TD-2, and detects a re-detection specific peak at the time point TD-3 indicated by o. Next, for the frequency spectrum at the time point TD-4 which is one time point before the time point TD-3, the peak re-detection section 24 performs a re-detection process in the second frequency range FW2 which includes the re-detection specific peak o at the time point TD-3, and detects a re-detection specific peak at the time point TD-4 indicated by o. Further, if the time point TD+1 which is one time point after the time point TD0, the peak detection continuation section 25 performs a peak detection continuation process at the time point TD+1 in the second frequency range FW2 which includes the specific peak • at the time point TD0, and detects a post-detection specific peak at the time point TD+1 indicated by o. If the time point TD+2, the peak detection continuation section 25 performs a peak detection continuation process at the time point TD+2 in the second frequency range FW2 which includes the post-detection specific peak o at the time point TD+1, and detects a post-detection specific peak at the time point TD+2 indicated by o. If the time point TD+3 this time, the peak detection continuation section 25 performs a peak detection continuation process at the time point TD+3 in the second frequency range FW2 which includes the post-detection specific peak o at the time point TD+2, and detects a post-detection specific peak at the time point TD+3 indicated by o. Further, the display processing section 26 displays the first mark • at the coordinate of the time point TD0 and the amplitude of the specific peak thereof in the display section 4, displays the second marks o respectively at the coordinates of the respective time points TD-1 to TD-4 and the respective amplitudes of the respective re-detection specific peaks thereof in the display section 4, and displays the third marks o respectively at the coordinates of the respective time points TD+1 to TD+3 and the respective amplitudes of the respective post-detection specific peaks thereof in the display section 4. Figure 5 B, the orthogonal coordinate system having the horizontal axis as the date with respect to the sampling period and the vertical axis as the amplitude is displayed in the display section 4, the first mark • is displayed in the display section 4 at the coordinate of the time point TD0 and the amplitude of the specific peak thereof, the second marks o are respectively displayed in the display section 4 at the coordinates of the respective time points TD-1 to TD-4 and the respective amplitudes of the respective re-detection specific peaks thereof, and the third marks o are respectively displayed in the display section 4 at the coordinates of the respective time points TD+1 to TD+3 and the respective amplitudes of the respective post-detection specific peaks thereof. Figure 5In the example shown in B, the second and third marks are the same mark ○, and the first mark is a different mark ● from the second and third marks.

[0073] In addition, Figure 6 In the example shown in B, the display processing unit 26 calculates the best-fitting curve β for the date and amplitude of the aforementioned specific peak with respect to the sampling period, the date and amplitude of the re-detected specific peak with respect to the sampling period, and the date and amplitude of the detected specific peak with respect to the sampling period in a coordinate space with time and amplitude as the coordinate axes, and displays the calculated fitting curve β on the display unit 4.

[0074] These control processing units 2, input units 3, display units 4, IF units 5, and storage units 6 can be, for example, composed of desktop, laptop, or other types of computers.

[0075] Next, the operation of this embodiment will be explained. Figure 7 This is a flowchart illustrating the operation of the aforementioned rolling bearing monitoring device prior to detecting a specific peak value. Figure 6 This is a flowchart illustrating the operation of the aforementioned rolling bearing monitoring device after detecting the aforementioned specific peak value.

[0076] When the power supply to the rolling bearing monitoring device 1000 with this structure is turned on, the necessary initialization of each part is performed, and the device begins to operate. In the control processing unit 2, the execution of the control processing program functionally constitutes the control unit 21, the spectrum processing unit 22, the peak detection unit 23, the peak re-detection unit 24, the peak detection continuation unit 25, and the display processing unit 26.

[0077] If the aforementioned work begins at the start point of the sampling period, then... Figure 7 First, the rolling bearing monitoring device 1000 obtains vibration data from the storage unit 6 by the spectrum processing unit 22 of the control processing unit 2 for a sampling period of length TW obtained by the first to third vibration detection sensors 1-1 to 1-3, and calculates the frequency spectrum of the vibration data (S11). The calculated frequency spectrum is then stored in the storage unit 6 in correspondence with the current sampling period (S12).

[0078] Next, the rolling bearing monitoring device 1000 uses the peak detection unit 23 of the control processing unit 2 to detect a specific peak value from the frequency spectrum during this sampling period within a predetermined first frequency range that includes the theoretical frequency (S13). If no specific peak value is detected and the detection result is negative (NO), the rolling bearing monitoring device 1000 terminates this process during this sampling period. On the other hand, if a specific peak value is detected and the aforementioned detection result is positive (YES), the rolling bearing monitoring device 1000 then executes process S14.

[0079] In this processing S14, the rolling bearing monitoring device 1000 stores the aforementioned detected specific peak (its sampling period, amplitude, and frequency) to the storage section 6 by the peak detection section 23 of the control processing section 2.

[0080] Next, the rolling bearing monitoring device 1000 detects a specific peak as a redetected specific peak by the peak redetection section 24 of the control processing section 2, and stores the detected redetected specific peak (its sampling period, amplitude, and frequency) to the storage section 6 (S15).

[0081] Then, the rolling bearing monitoring device 1000 displays the specific peak and the redetected specific peak on the display section 4 by the display processing section 26 of the control processing section 2 (S16), and ends this processing in the sampling period. Also, the aforementioned detection results can be outputted to an external device via the IF section 5 as needed.

[0082] On the other hand, if it becomes the sampling period after the aforementioned specific peak is detected, in Figure 5 first, the rolling bearing monitoring device 1000 calculates the frequency spectrum of the vibration data in the sampling period by the frequency spectrum processing section 22 of the control processing section 2 (S21), and stores the calculated frequency spectrum to the storage section 6 in correspondence with the sampling period (S22) as with the processing S11 described above.

[0083] Next, the rolling bearing monitoring device 1000 detects a post-detection specific peak in the sampling period by the peak detection continuation section 25 of the control processing section 2, and stores the detected post-detection specific peak (its sampling period, amplitude, and frequency) to the storage section 6 (S23).

[0084] Then, the rolling bearing monitoring device 1000 displays the specific peak, the redetected specific peak, and the post-detection specific peak detected up to this point on the display section 4 by the display processing section 26 of the control processing section 2 (S24), and ends this processing in the sampling period.

[0085] Generally, in the case where some kind of obstacle that hinders smooth rolling occurs in the rolling bearing BE in a normal state, after the amplitude of the peak value becomes large as the aforementioned obstacle develops, the aforementioned peak value can be determined, and the frequency of the peak value can be specified. On the other hand, it is presumed that the peak value before being specified occurs in the vicinity of the specified frequency. As explained above, the rolling bearing monitoring device 1000 and the rolling bearing monitoring method installed therein according to the embodiment can more reliably detect the specified peak value since the specified peak value is detected in the first frequency range FW1 including the theoretical frequency, and can more correctly detect the specified peak value that is caused by the occurrence of the aforementioned obstacle since the specified peak value is detected again in the second frequency range FW2 that is narrower than the aforementioned first frequency range FW1, and the confusing peak value that is included in the first frequency range but is not caused by the occurrence of the aforementioned obstacle is excluded from the detection target. Furthermore, the user can grasp the transition of the past peak value amplitude by displaying in the display section the amplitude value of the peak value that is caused by the obstacle occurring in the rolling bearing how it is in the period earlier than the point of time at which the peak value can be detected.

[0086] The aforementioned rolling bearing monitoring device 1000 and rolling bearing monitoring method can more reliably detect the redetected specified peak value since the redetected specified peak value is detected in the second frequency range FW2 including the redetected specified peak value detected by the first peak value redetection process, in the case where the frequency of the redetected specified peak value changes with time.

[0087] The aforementioned rolling bearing monitoring device 1000 and rolling bearing monitoring method can detect the specified peak value in the sampling period later than the sampling period in the case where the specified peak value is detected by the peak value detection process, and can continue the detection of the specified peak value since the peak value detection continuation process is performed.

[0088] The aforementioned rolling bearing monitoring device 1000 and rolling bearing monitoring method can more reliably detect the detected-after specified peak value since the detected-after specified peak value is detected in the second frequency range FW2 including the detected-after specified peak value detected by the first peak value detection continuation process, in the case where the frequency of the detected-after specified peak value changes with time.

[0089] The rolling bearing monitoring device 1000 and the rolling bearing monitoring method described above enable the user (operator) to visually confirm the time variation of the re-detection specific peak, the specific peak, and the post-detection specific peak, and to visually confirm the development of the aforementioned obstacle (time variation tendency, trend) because the time information about the sampling period and the amplitude of the aforementioned detected specific peak in the case where the specific peak is detected by the aforementioned peak detection process, the time information about the sampling period and the amplitude of the aforementioned detected re-detection specific peak in the case where the re-detection specific peak is detected by the aforementioned peak re-detection process, and the time information about the sampling period and the amplitude of the aforementioned detected post-detection specific peak in the case where the post-detection specific peak is detected by the aforementioned peak detection continuation process are displayed in the orthogonal coordinate system.

[0090] The time until the rolling bearing needs to be replaced, i.e., the remaining life ((time information about the sampling period in the frequency spectrum (vibration data) in which the specific peak is detected) + (the remaining life at that time) = (replacement period)) after the specific peak is detected depends on the development of the aforementioned obstacle. The user can know, for example, that the replacement period is approaching in the case where the first mark •, the second mark X, and the third mark X are displayed by referring to the display. Figure 5 A shows an example in which the development of the aforementioned obstacle progresses more quickly than Figure 8 B shows an example in which the development of the aforementioned obstacle progresses more quickly than In particular, the remaining life is easily predicted by referring to the display of the fitting curve a. The maintenance plan of the monitoring object can be more reliably made, and the equipment maintenance becomes easy by the prediction of the remaining life.

[0091] Further, the user can estimate the occurrence period of the aforementioned obstacle by referring to the most past re-detection specific peak. In particular, the user easily finds the period in which the fitting curve a rises (= the occurrence period of the aforementioned obstacle) and easily estimates the occurrence period of the aforementioned obstacle by referring to the display of the fitting curve a.

[0092] In addition, in the embodiment described above, the data recorder 7 can be provided between the vibration detection sensor 1 and the control processing section 2, and the spectrum processing section 22 can be provided in the data recorder 7.

[0093] Figure 8 is a block diagram showing the structure of a rolling bearing monitoring device according to a modified example of the embodiment. The rolling bearing monitoring device 1000a according to the modified example, for example, as shown in Figure 1 has the vibration detection sensor 1, the data recorder 7, the control processing section 2, the input section 3, the output section 4, the IF section 5, and the storage section 6.

[0094] The vibration detection sensor 1, the control processing section 2, the input section 3, the output section 4, the IF section 5, and the storage section 6 in the rolling bearing monitoring device 1000a are the same as those in the rolling bearing monitoring device 1000 except that a part of the functions of the control processing section 2 and a part of the functions of the storage section 6 are moved to the data logger 7, so the description thereof is omitted. The control processing section 2 has the control section 21, the peak detection section 23, the peak re-detection section 24, the peak detection continuation section 25, and the display processing section 26 in terms of functions, and the function of the spectrum processing is moved to the data logger 7. The function of storing the vibration data and the frequency spectrum thereof is moved to the data logger 7.

[0095] The data logger 7 is connected to the vibration detection sensor 1 and the control processing section 2, respectively, and is configured with, for example, a computer, and has a data logger control processing section 71 and a data logger storage section 72. The data logger control processing section 71 is configured with a CPU and a peripheral circuit thereof, and has the spectrum processing section 22 which functions in the same manner as described above in terms of functions, except that the data logger storage section 72 stores in place of the storage section 6. The data logger storage section 72 has a ROM, an EEPROM, a RAM, a hard disk device, or the like, and stores the vibration data and the frequency spectrum described above. The data logger 7 outputs the frequency spectrum of the vibration data described above to the control processing section 2 on demand (request) of the control processing section 2.

[0096] In order to embody the present application, the above-described ​ The present application has been described adequately and sufficiently by the embodiments, but it should be recognized by those skilled in the art that the above-described embodiments can be easily changed and / or modified. Thus, as long as the changed or modified form implemented by those skilled in the art is not at a level that deviates from the scope of the claims recited in the claims, the changed or modified form is interpreted as being included in the scope of the claims.

[0097] Explanation of Reference Numerals

[0098] BE (BE-1 to BE-3) Rolling bearing (first to third rolling bearings)

[0099] FW1 First frequency range

[0100] FW2 Second frequency range

[0101] 1000 Rolling bearing monitoring device

[0102] 1 (1-1 to 1-3) Vibration detection sensor (first to third vibration detection sensors)

[0103] 2 Control processing section

[0104] 4 display section

[0105] 6 storage section

[0106] 7 data recorder

[0107] 21 control section

[0108] 22 spectrum processing section

[0109] 23 peak detection section

[0110] 24 peak re-detection section

[0111] 25 peak detection continuation section

[0112] 26 display processing section

Claims

1. A rolling bearing monitoring method characterized by comprising: a spectrum processing step of acquiring vibration data representing vibrations occurring in a rolling bearing at a predetermined acquisition interval for a predetermined sampling period, and calculating a frequency spectrum of the vibration data for the sampling period, and storing the calculated frequency spectrum in correspondence with the sampling period in a storage unit; a peak detection step of detecting a specific peak value that does not occur when the rolling bearing is normal from the frequency spectrum in a predetermined first frequency range including a theoretical frequency that brings about a peak value on the frequency spectrum when an abnormality occurs; a peak re-detection step of, in a case where a specific peak value is detected by the peak detection step, detecting a specific peak value that does not occur when the rolling bearing is normal as a re-detected specific peak value in a predetermined second frequency range narrower than the first frequency range and including a frequency of the specific peak value detected by the peak detection step, from one or more frequency spectra stored in the storage unit for a sampling period earlier than the sampling period in which the specific peak value is detected; a display step of displaying, on a display unit, time information about the sampling period and an amplitude of the detected specific peak value in a case where a specific peak value is detected by the peak detection step, and time information about the sampling period and an amplitude of the detected re-detected specific peak value in a case where a re-detected specific peak value is detected by the peak re-detection step.

2. The rolling bearing monitoring method according to claim 1, characterized in that the peak re-detection step, in a case where the re-detected specific peak value is detected in a past direction with respect to the plurality of frequency spectra, regards the peak detection step and the specific peak value detected by the peak detection step as each an initial peak re-detection step and an initial re-detected specific peak value for each of the plurality of frequency spectra, and detects the re-detected specific peak value in the second frequency range including the re-detected specific peak value detected by the first peak re-detection step for the frequency spectrum.

3. The rolling bearing monitoring method according to claim 1, characterized in that the display step displays, on the display unit, an orthogonal coordinate system having an abscissa axis representing time information about the sampling period and an ordinate axis representing the amplitude, displays a predetermined first mark on the display unit at a first coordinate represented by the time information about the sampling period and the amplitude of the detected specific peak value in a case where a specific peak value is detected by the peak detection step, and displays a predetermined second mark on the display unit at a second coordinate represented by the time information about the sampling period and the amplitude of the detected re-detected specific peak value in a case where a re-detected specific peak value is detected by the peak re-detection step.

4. The rolling bearing monitoring method according to claim 1, characterized by further comprising a peak detection continuation step of, in a case where a specific peak value is detected by the peak detection step, detecting a specific peak value that does not occur when the rolling bearing is normal in a predetermined third frequency range narrower than the second frequency range and including a frequency of the specific peak value detected by the peak detection step, from one or more frequency spectra stored in the storage unit for a sampling period earlier than the sampling period in which the specific peak value is detected. ​ ​ ​ The aforementioned peak detection continuation process is a process of detecting, as a detection-after-peak-detection peak, a specific peak that does not occur when the rolling bearing is normal, in a predetermined second frequency range that is narrower than the aforementioned first frequency range and that includes the aforementioned specific peak, for a frequency spectrum stored in the aforementioned storage section at a sampling period later than the sampling period at which the aforementioned specific peak is detected by the aforementioned peak detection process; The aforementioned display process further displays, in the aforementioned display section, the sampling period and the amplitude of the detection-after-peak-detection peak detected by the aforementioned peak detection continuation process, at a sampling period later than the sampling period at which the aforementioned specific peak is detected.

5. The rolling bearing monitoring method according to claim 4, wherein The aforementioned peak detection continuation process regards the aforementioned peak detection process and the specific peak detected by the aforementioned peak detection process as an initial peak detection continuation process and an initial detection-after-peak-detection peak, respectively, and detects the aforementioned detection-after-peak-detection peak in the aforementioned second frequency range that includes the detection-after-peak-detection peak detected by the first peak detection continuation process at the sampling period, for a frequency spectrum stored in the aforementioned storage section at the sampling period.

6. The rolling bearing monitoring method according to claim 4 or 5, wherein The aforementioned display process is a process of displaying, in the aforementioned display section, an orthogonal coordinate system in which a horizontal axis is time information with respect to the aforementioned sampling period and a vertical axis is the aforementioned amplitude, displaying a predetermined first mark in a first coordinate in the aforementioned display section, displaying a predetermined second mark in a second coordinate in the aforementioned display section, and displaying a predetermined third mark in a third coordinate in the aforementioned display section, the first coordinate being represented by the time information with respect to the sampling period and the amplitude of the detected specific peak in a case where a specific peak is detected by the aforementioned peak detection process, the second coordinate being represented by the time information with respect to the sampling period and the amplitude of the detected re-detected specific peak in a case where a re-detected specific peak is detected by the aforementioned peak re-detection process, and the third coordinate being represented by the time information with respect to the sampling period and the amplitude of the detected detection-after-peak-detection peak in a case where a detection-after-peak-detection peak is detected by the aforementioned peak detection continuation process.

7. The rolling bearing monitoring method according to claim 1, wherein The length of the aforementioned sampling period is set based on the aforementioned second frequency range, and the narrower the aforementioned second frequency range, the longer the sampling period is set to be.

8. A rolling bearing monitoring apparatus, comprising: a vibration detection sensor that acquires vibration data representing vibration generated by a rolling bearing; a storage section; a control processing section that performs a frequency spectrum process, a peak detection process, a peak re-detection process, and a display process; and a display section; the aforementioned frequency spectrum process is a process of acquiring, at a predetermined sampling period, at a predetermined acquisition interval, a frequency spectrum of the vibration data in the sampling period, and storing the aforementioned acquired frequency spectrum in the storage section in correspondence with the sampling period; the aforementioned peak detection process is a process of detecting, as a specific peak, a peak that does not occur when the rolling bearing is normal, in a predetermined first frequency range, for a frequency spectrum stored in the aforementioned storage section at a sampling period, and the aforementioned peak re-detection process is a process of detecting, as a re-detected specific peak, a peak that does not occur when the rolling bearing is normal, in a predetermined second frequency range, for a frequency spectrum stored in the aforementioned storage section at a sampling period later than the sampling period at which the aforementioned specific peak is detected by the aforementioned peak detection process, and the aforementioned display process is a process of displaying, in the aforementioned display section, an orthogonal coordinate system in which a horizontal axis is time information with respect to the aforementioned sampling period and a vertical axis is the aforementioned amplitude, displaying a predetermined first mark in a first coordinate in the aforementioned display section, displaying a predetermined second mark in a second coordinate in the aforementioned display section, and displaying a predetermined third mark in a third coordinate in the aforementioned display section, the first coordinate being represented by the time information with respect to the sampling period and the amplitude of the detected specific peak in a case where a specific peak is detected by the aforementioned peak detection process, the second coordinate being represented by the time information with respect to the sampling period and the amplitude of the detected re-detected specific peak in a case where a re-detected specific peak is detected by the aforementioned peak re-detection process, and the third coordinate being represented by the time information with respect to the sampling period and the amplitude of the detected detection-after-peak-detection peak in a case where a detection-after-peak-detection peak is detected by the aforementioned peak detection continuation process. The aforementioned peak detection processing is processing of detecting a specific peak that does not occur when the rolling bearing is normal from the aforementioned frequency spectrum in a predetermined first frequency range that includes a theoretical frequency that brings about a peak on the frequency spectrum at the time of occurrence of an anomaly; The aforementioned peak re-detection processing is processing of, in a case where the specific peak is detected by the aforementioned peak detection processing, detecting, as a re-detection specific peak, a specific peak that does not occur when the rolling bearing is normal in a predetermined second frequency range that is narrower than the aforementioned first frequency range and that includes a frequency of the aforementioned specific peak detected by the aforementioned peak detection processing, for one or a plurality of frequency spectra stored in the aforementioned storage section for a period earlier than a sampling period at the time of detection of the aforementioned specific peak; The aforementioned display processing is processing of displaying, in the aforementioned display section, time information about a sampling period and an amplitude of the aforementioned detected specific peak in a case where the specific peak is detected by the aforementioned peak detection processing, and time information about a sampling period and an amplitude of the aforementioned detected re-detection specific peak in a case where the re-detection specific peak is detected by the aforementioned peak re-detection processing.

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